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General Forums => The Mess Hall => Topic started by: andrew383 on July 31, 2009, 03:05:06 PM
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cranks just fine but i have no fire from the coil.
Things i have checked-
1) both crank and cam sensor's have been swapped out
2) coil has been swapped
3) wires from ecm to plugs for coil,crank and cam have been checked
4) ASD and FP relays have been switched around and both function
5) i have the 5v at the cam sensor
6) battery has been unplugged and ecm reset
7) when i remove the ASD relay the FP still kicks on when the key is turned on
Ive pretty much ran out of ideas here and need some help :wall:
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When my YJ was like that it turned out to be the computer itself. I'm sure the TJ is different but on the YJ the main clue was that the check engine light was not coming on for a while when the key was tuned to RUN.
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it comes on for a few seconds then goes away when the key is turned on
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Have you checked the codes from the ECM? If nothing comes up I would get the computer checked to rule it out.
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i tried the way its told on JF with the key on/off deal but the light never flashed
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I´m not sure if the 97 is like my 95 but on mine you have to cycle the key pretty fast to get it to work. I think on the TJs you get acual code numbers on the odometer readout instead of just flashes on the check engine light.
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I've never been able to get my 97' to code with the 3 turns of the ignition. My sisters 01' worked everytime though? I'd borrow/rent a code reader from an auto store.
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Well here are a few simple checks, do the injectors fire when you plug a noid light in? In other words with either a noid light or a small light bulb or test light does it flicket when you crank it? If so the coil is bad, if not see if you can get an rpm reading from the engine, either from the tach or beg borrow or steal an OBD 2 scanner and see if it gives you cranking rpm in the datastream, which would mean that the crancksensor and wiring to the ecm is good. Also when you crank it does it engage the ASD relais? Which would mean that the ecm does see an rpm reading from the crank sensor. If all that is happy look at the ignition module.
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Well here are a few simple checks, do the injectors fire when you plug a noid light in? In other words with either a noid light or a small light bulb or test light does it flicket when you crank it? If so the coil is bad, if not see if you can get an rpm reading from the engine, either from the tach or beg borrow or steal an OBD 2 scanner and see if it gives you cranking rpm in the datastream, which would mean that the crancksensor and wiring to the ecm is good. Also when you crank it does it engage the ASD relais? Which would mean that the ecm does see an rpm reading from the crank sensor. If all that is happy look at the ignition module.
did you see what all ive done so far?
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heard of this once and the distributor was out of sync (the cam signal was out of sync with the crank signal) - the ecu would err and not send issue a spark in that case, cant think of anything else out of the ordinary and since it seems that you did quite a bit of checks i won't go into the obvious ones.
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the dist has not been moved at all,im really at a loss here as to what to do next :brick:
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the dist has not been moved at all,im really at a loss here as to what to do next :brick:
i'll try and list what i can think of, you might have done all this but have a look:
one thing to check again is the voltage at the camshaft positon sensor - it is supposed to be 8v and not 5v (that's on my 95YJ). also check the voltage at the crank sensor as well (same there, 8v in my case).
I am assuming you did all the following but i'll list them anyway: check if the distributor is rotating, check 12v at the coil, test the coil, check 12v at injectors (all ASD related), check that you get ground while cranking at the injectors (or do the light bulb test like aw suggested), and since you said you have 5v at the cam sensor (or 8v?) that means you have power at the ECU. I would check the MAP sensor 5v and output (you should get 4.65v or so when you put the contact, and if you have a vacuum pump check that the voltage goes towards zero the more vacuum you apply). Also you might want to check the grounds as well at the sensors and that you have 12v ignition on pin 9 at the ecu (you should based on what you checked so far, white/yellow wire).
i would say if you gone thru all the above plus the ones you listed you could check the signals coming from the cam and crank with an oscilloscope and see if you get signals while cranking and to also check that your signals are in sync (it's a long shot as you mentioned that the distributor hasn't moved but you might want to look at it anyway if you have to oscilloscope connected - preferably one with 2 inputs/probes in that case).
I read this article a while ago and this image is relevant in this case: http://www.asashop.org/autoinc/feb99/img/fig4.gif with the explanation below:
# Dst Sync (cam sensor) MUST be seen prior to crank signal.
# Crank signal is x amount of degrees after cam signal.
# Primary ignition signal is seen.
# Injector signal is turned on.
# Once in order, the PCM sees everyone is OK and allows the engine to run. Any other sequence and the PCM shuts down after two sparks!
and this is the link to the article http://www.asashop.org/autoinc/feb99/techtotech.htm - it is related to a 4.0L, but the idea is the same - just in case you run out of options.
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well im going to recheck all the voltages at the coil,crank,cam senors,and also at the injectors then if all that checks out its new ecm time i guess :)
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Before you spend the big bucks for a new PCM you need to
1.check the faults.
2. check the voltage going into the coil?
3.There is a sync that needs to be run on the cam crank that you need a diagnostic tool to run.
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i'll try and list what i can think of, you might have done all this but have a look:
one thing to check again is the voltage at the camshaft positon sensor - it is supposed to be 8v and not 5v (that's on my 95YJ). also check the voltage at the crank sensor as well (same there, 8v in my case).
I am assuming you did all the following but i'll list them anyway: check if the distributor is rotating, check 12v at the coil, test the coil, check 12v at injectors (all ASD related), check that you get ground while cranking at the injectors (or do the light bulb test like aw suggested), and since you said you have 5v at the cam sensor (or 8v?) that means you have power at the ECU. I would check the MAP sensor 5v and output (you should get 4.65v or so when you put the contact, and if you have a vacuum pump check that the voltage goes towards zero the more vacuum you apply). Also you might want to check the grounds as well at the sensors and that you have 12v ignition on pin 9 at the ecu (you should based on what you checked so far, white/yellow wire).
i would say if you gone thru all the above plus the ones you listed you could check the signals coming from the cam and crank with an oscilloscope and see if you get signals while cranking and to also check that your signals are in sync (it's a long shot as you mentioned that the distributor hasn't moved but you might want to look at it anyway if you have to oscilloscope connected - preferably one with 2 inputs/probes in that case).
I read this article a while ago and this image is relevant in this case: http://www.asashop.org/autoinc/feb99/img/fig4.gif with the explanation below:
# Dst Sync (cam sensor) MUST be seen prior to crank signal.
# Crank signal is x amount of degrees after cam signal.
# Primary ignition signal is seen.
# Injector signal is turned on.
# Once in order, the PCM sees everyone is OK and allows the engine to run. Any other sequence and the PCM shuts down after two sparks!
and this is the link to the article http://www.asashop.org/autoinc/feb99/techtotech.htm - it is related to a 4.0L, but the idea is the same - just in case you run out of options.
i shouldnt have 12v at the injectors should i?When the key is on there shouldnt be any voltage correct?
i did check out the wire(s) back to the ecm and there ok and the other wire was ground.Thge asd relay is clicking when the key is turned on and the fuelpump is also coming on.
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i shouldnt have 12v at the injectors should i?When the key is on there shouldnt be any voltage correct?
i did check out the wire(s) back to the ecm and there ok and the other wire was ground.Thge asd relay is clicking when the key is turned on and the fuelpump is also coming on.
when you crank it you should get 12v - you're correct, the injectors are powered by the ASD, so whenever that closes you will have 12v at the injectors, coil and O2 sensor.
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one other thing is when the ASD relay is pulled the fuelpump STILL kicks on
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one other thing is when the ASD relay is pulled the fuelpump STILL kicks on
the fuel pump relay is separate - the feed is the same (circuit A14), they are controlled by different circuits - page 18 and 15 of 95YJ_8W.pdf from FSM (or by their numbering page 8w-11-6 and 8w-11-3)
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the fuel pump relay is separate - the feed is the same (circuit A14), they are controlled by different circuits - page 18 and 15 of 95YJ_8W.pdf from FSM (or by their numbering page 8w-11-6 and 8w-11-3)
yes but with the ASD relay pulled and the FP relay still in shouldnt the FP be dead when the key is on?
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yes but with the ASD relay pulled and the FP relay still in shouldnt the FP be dead when the key is on?
mine clicks in when i turn the key on and turns off after a couple of seconds. Once you start cranking it should power the pump. There is an ASD sense pin on the ECU, not sure what happens when you pull the ASD relay if the fuel pump will still spin, if i have time i'll test and see what happens on mine.
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ok i rechecked a few things today.The coil HAS 12v at the plug,the injectors also HAVE 2v at the plugs,but i still dont have any spark through the coil.The cam/crank sensors have 5v at the plug which is what the haynes calls for.Soooo ill test/swap the coil,and cam/crank sensors AGAIN.
What else is there to check?If the coil and the sensors check out what else what not spark?
There is ONE problem i didnt mention before but when i put the gas tank skid on about 4 months ago i messed up the check valve and have had to do the "turn key 3 times" deal and havent had a problem other wise.I did have the FP checked and on the key on its 32psi and 2nd is 50psi.If i was getting spark but no fuel then i would think that was the problem but since there is no spark i dont think it is.
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did you check if your distributor is rotating/spinning?
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yes checked with cap off...
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this is for sure interesting (unless is the ecu/pcm). keep us posted with what you find.
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sorry i didnt get back with you andrew, the batt temp sensor shouldnt have anything to do with the starting circuit...you could track the wire down and unplug it and try that. As far as i know there are only 2 sensors that tell the computer to fire the coil...but if you're holding a constant 12v TO the coil then i'd say those sensors are working. I wouldnt think you'd have voltage at the coil if they werent. I would prolly try the coil first. How do the contacts on the rotor button and cap look? worn? corroded? nicked?
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You still haven't answered this question, when you crank the engine do the asd relais and fuel pump relais engage and do the injectors pulse?
IT's not all that important that those relais turn on when you cycle the key
If they come on when cranking it means the ecm gets a signal from the cranksensor
Then if the injectors pulse it means that the ignition module works saves a lot of time. Instead of measuring voltage here and there. Check the basics keep it simple if it does all that and there is no spark the coil or the wiring to or from it is faulty.
All of the above can be checked with a simple test light and should not take all that long. Even if the distributor for some reason is way out of time due to say a jumped timing chain, as long as it turns it should make spark. Probably will not run but you should have spark
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You still haven't answered this question, when you crank the engine do the asd relais and fuel pump relais engage and do the injectors pulse?
IT's not all that important that those relais turn on when you cycle the key
If they come on when cranking it means the ecm gets a signal from the cranksensor
Then if the injectors pulse it means that the ignition module works saves a lot of time. Instead of measuring voltage here and there. Check the basics keep it simple if it does all that and there is no spark the coil or the wiring to or from it is faulty.
All of the above can be checked with a simple test light and should not take all that long. Even if the distributor for some reason is way out of time due to say a jumped timing chain, as long as it turns it should make spark. Probably will not run but you should have spark
i checked the injector plug with a meter and test light.When its turning over the volts just drop down to 11 but they dont pulse.Same thing with test light it just dims alittle.
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i checked the injector plug with a meter and test light.When its turning over the volts just drop down to 11 but they dont pulse.Same thing with test light it just dims alittle.
you should have 12v when cranking at the ASD side of the injectors but if you measure between the connector terminals you should have 0v and get a "pulse" once every 2 crank rotations (the ecu will ground 1 wire per cycle for each injector). The start of the sequence is given by the cam sensor (distributor sensor).
also thinking of another thread where the guy had problems with the engine interrupting and it turned out there was oil in the distributor which was causing the problem, someone else also mentioned that his engine stopped running due to the same reason, you might want to have a look just in case. They both said it worked fine after cleaning all that oil out of the distributor.
this is the camshaft position sensor test procedure from the 94/95 XJ/YJ FSM - it will tell you if the sensor is giving the appropriate signal (not sure if 97 is the same but i think the idea is similar, and most likely the same idea for the crank sensor) - this is on page 6 from 95XJ_8D.pdf
CAMSHAFT POSITION SENSOR TEST
To perform a complete test of this sensor and its circuitry, refer to the DRB scan tool.
Also refer to the appropriate Powertrain Diagnostics Procedures manual.
To test the sensor only, refer to the following:
....
For this test, an analog (non-digital) voltmeter is needed. Do not remove the distributor connector from the distributor.
Using small paper clips, insert them into the backside of the distributor wire harness connector to make contact with the terminals.
Be sure that the connector is not damaged when inserting the paper clips. Attach voltmeter leads to these paper clips.
(1) Connect the positive (+) voltmeter lead into the sensor output wire. This is at done the distributor wire harness connector. For wire identification, refer to Group 8W, Wiring Diagrams.
(2) Connect the negative (-) voltmeter lead into the ground wire. For wire identification, refer to Group 8W, Wiring Diagrams.
(3) Set the voltmeter to the 15 Volt DC scale.
(4) Remove distributor cap from distributor (two screws). Rotate (crank) the engine until the distributor rotor is pointed to approximately the 11 o’clock position. The movable pulse ring should now be within the sensor pickup.
(5) Turn ignition key to ON position. The voltmeter should read approximately 5.0 volts.
(6) If voltage is not present, check the voltmeter leads for a good connection.
(7) If voltage is still not present, check for voltage at the supply wire. For wire identification, refer to Group 8W, Wiring Diagrams.
( 8 ) If voltage is not present at supply wire, check for voltage at pin-7 of powertrain control module (PCM) 60-way connector.
Leave the PCM connector connected for this test.
(9) If voltage is still not present, perform vehicle test using the DRB scan tool.
( 10 ) If voltage is present at pin-7, but not at the supply wire:
(a) Check continuity between the supply wire. This is checked between the distributor connector and pin-7 at the PCM.
If continuity is not present, repair the harness as necessary.
(b) Check for continuity between the camshaft position sensor output wire and pin-44 at the PCM.
If continuity is not present, repair the harness as necessary.
(c) Check for continuity between the ground circuit wire at the distributor connector and ground.
If continuity is not present, repair the harness as necessary.
(11) While observing the voltmeter, crank the engine with ignition switch. The voltmeter needle should fluctuate between 0 and 5 volts while the engine is cranking. This verifies that the camshaft position sensor in the distributor is operating properly and a sync pulse signal is being generated.
If sync pulse signal is not present, replacement of the camshaft position sensor is necessary.
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i checked the injector plug with a meter and test light.When its turning over the volts just drop down to 11 but they dont pulse.Same thing with test light it just dims alittle.
you should have 12v when cranking at the ASD side of the injectors but if you measure between the connector terminals you should have 0v and get a "pulse" once every 2 crank rotations (the ecu will ground 1 wire per cycle for each injector). The start of the sequence is given by the cam sensor (distributor sensor).
Here is the answer to your problem.
If the injectors do not puls it means either the ecm does not see a signasl from the crank sensor or the ignition module does not get that info or failed.
Now if the ASD relais and the fuelpump relais engage, it means that the ecm does get a signal. If you could find a obd2 scanner somewhere it would show cranking rpm while cranking. So you would look for a signal at the ecm that goes to the coil.
From what it looks like it would not hurt to try swapping the ecm if that is a remote posibility. Since the ignition module is integrated into the ecm/pcm.
Got to hate this integrated stuff
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i checked the injector plug with a meter and test light.When its turning over the volts just drop down to 11 but they dont pulse.Same thing with test light it just dims alittle.
you should have 12v when cranking at the ASD side of the injectors but if you measure between the connector terminals you should have 0v and get a "pulse" once every 2 crank rotations (the ecu will ground 1 wire per cycle for each injector). The start of the sequence is given by the cam sensor (distributor sensor).
Here is the answer to your problem.
If the injectors do not puls it means either the ecm does not see a signasl from the crank sensor or the ignition module does not get that info or failed.
Now if the ASD relais and the fuelpump relais engage, it means that the ecm does get a signal. If you could find a obd2 scanner somewhere it would show cranking rpm while cranking. So you would look for a signal at the ecm that goes to the coil.
From what it looks like it would not hurt to try swapping the ecm if that is a remote posibility. Since the ignition module is integrated into the ecm/pcm.
Got to hate this integrated stuff
you quoted my statement but i'm not sure if you agreed or otherwise. just in case i didn't explain properly the first time: you need a cam signal or the injectors will not be open by the pcm. the cam sensor tells the pcm when cyl 1 is at compression. the injectors are opened by a ground given to the control terminal of each injector (individually) in sequence (not all at the same time). so if he sees the injectors opening it means he's got cam signal.
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Doesn't the cam sensor just sync the injectors? Might be of topic somewhat but just trying to get the Jeep specifics straight, they are a bit of an odd beast
Even with out the cam signal it should have ingintion spark right, so it would point back towards pcm/ ignition module?
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not knowing if it would work i swapped in a 95 zj 4.0 ecm and i still have no spark....i still need to retest the injector pulse tho
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Doesn't the cam sensor just sync the injectors? Might be of topic somewhat but just trying to get the Jeep specifics straight, they are a bit of an odd beast
Even with out the cam signal it should have ingintion spark right, so it would point back towards pcm/ ignition module?
not sure but i see what you mean - since the crank would alternate tdc for pistons 1-4 and 2-3 you could be right that it does not actually need the cam sensor to give spark, however according to that article that i posted the link for in this thread if the cam/crank are not seen in sync by the pcm it will not give spark, so by that account i assume that if there is no cam signal at all there shouldn't be a spark either.
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not knowing if it would work i swapped in a 95 zj 4.0 ecm and i still have no spark....i still need to retest the injector pulse tho
don't think so since is programmed to see 3 groups of 4 teeth at the crank for 1 cam signal - if it gives you spark then you know it's the pcm, if it doesn't you're at square zero as you don't know if it is because it's a 6cyl pcm or not.
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ok i have 12v with key on at inj but no pulsing on any of them when cranking.When i turn the key on the asd relay will click twice and 5 sec apart.Is there a way to bypass the asd relay?Im fixin to do the camsensor test that was posted. :brick: :rant:
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you don't need to bypass the asd to test the camsensor - make sure your multimeter is a needle one and not a digital.
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tested the cam sensor and i have 5v on both out side wires and the middle is ground.The one outside wire will light the test light and the other wont but they both read 5v with a meter.
i went and bought an anolog meter this morning just for injector testing :mad: i still didnt get any pulse from the injectors BUT the inside of the intake manifold is wet with gas so not really sure whats up with that.
Im really at wits end here guys i just dont know whatelse to to do but change the ecm... :brick: :brick: :brick: :brick:
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did you use the analog multimeter to test the cam sensor? go thru the testing procedure and see if you get a pulse while crancking on the cam sensor as per testing instructions.
EDIT: while you're at it test the crank sensor as well (you can find the testing procedure in the same pdf as the cam sensor test)
you could test with another ecm, that would be a quick rule-out or confirmation if that's the problem. btw, do you see voltage between the injector terminals? you shouldn't, you should only see a quick spike while cranking.
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ok retested the cam sensor and i get the pulse from it.The injectors still have NO pulse!!I do however have fuel IN the intake manifold. What else is there? (http://i230.photobucket.com/albums/ee313/andrew383/jeep/th_MOV01897.jpg) (http://s230.photobucket.com/albums/ee313/andrew383/jeep/?action=view¤t=MOV01897.flv)
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ok retested the cam sensor and i get the pulse from it.The injectors still have NO pulse!!I do however have fuel IN the intake manifold. What else is there? (http://i230.photobucket.com/albums/ee313/andrew383/jeep/th_MOV01897.jpg) (http://s230.photobucket.com/albums/ee313/andrew383/jeep/?action=view¤t=MOV01897.flv)
test the crank sensor using the same method. not sure how you got fuel in the intake. if your crank generates a pulse/signal then it is likely to be the PCM (unless you've got that weird situation where the crank and cam are out of sync). Not sure what to tell you, would be great if you could borrow a pcm and test with it - that would be a quick way to evaluate it (or maybe take your ecu and put it on another vehicle to see if it works, that might be even quicker). keep us posted.
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OOOOOOOOOOOKKKKKKKKKk whole new batch of cookies :koolaid:
ok so i went back out and started messing with the coil power/ASD.I bypassed the ASD with a jumper and BAM fired rite up :brick:.
Sooo put the relay back in and no fire,swapped with the FP relay and still no fire,jumped it again and fired rite up.
When it fired up it wouldnt idle without me pressing on the pedal,after it ran for a min and a few rev's it idled but has a dead mis.The mis IS NOT constant but happens about every 5 sec.
Sooo what is the ASD not seeing that it needs to?
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didn't you say you were getting 12v at the injectors (i think that is given by the ASD)? or am i mixing this with another thread. did you check to see if you have 12v at the coil side of the ASD (pin 86 or 87, can't remember) - my recollection is that the ecu is controlling it by ground to one of those 2 pins and the other one has 12v when you turn the key in run position. since it runs it means you have crank signal, otherwise you wouldn't have ignition/spark. interesting is that your FP relay is working and the ASD not.
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i looked at the diagrams for the 94/95 wrangler in FSM - look at pages 44 and 50 in the 95YJ_8W.pdf file. the coil side of the relay is the same (both positive and ground) for both ASD and FP relay. even more the feed for the contacts side is the same. so unless there is a wiring problem and assuming the connections are the same for your year you should have power at the asd when your FP relay gives power. i would check to see if there is a wiring prob there and if you have 12v on the coil and contact side of the ASD (again, assuming that your model is the same with 94/95).
from that document this is the description of how ASD operates
AUTOMATIC SHUT DOWN (ASD) RELAY
When the ignition switch is in either the START or
RUN position, it connects circuit A1 from fuse 4 in
the Power Distribution Center (PDC) to circuit A21.
Circuit A21 powers fuse 5 in the fuse block. Circuit
G50 from fuse 5 splices to power the coil side of the
Automatic Shut Down (ASD) relay. The Powertrain
Control Module (PCM) provides ground for the relay
on circuit K51. Circuit K51 connects to cavity 51 of
the PCM.
When the PCM grounds the ASD relay, contacts inside
the relay close and connect circuit A14 from fuse
1 in the PDC to circuit A142. Circuit A142 splices to
the generator field terminal, fuel injectors, ignition
coil, and heated oxygen sensor. Circuit A142 also connects
to cavity 57 of the PCM.
Circuit A14 from fuse 1 in the PDC supplies battery
voltage to the contact side of the ASD relay.
HELPFUL INFORMATION
˛ Along with supplying voltage to the ASD relay
contacts, circuit A14 supplies voltage to the contact
side of the fuel pump relay.
˛ Circuit G50 also supplies battery voltage to the
coil side of the fuel pump relay.
˛ Circuit A14 also connects to cavity 3 of the PCM.
J 8W-30 FUEL/IGNITION—YJ VEHICLES 8W - 30 - 1
BATTERY FEED
Circuit A14 from fuse 1 in the Power Distribution
Center (PDC) supplies battery voltage to cavity 3 of
the Powertrain Control Module (PCM).
HELPFUL INFORMATION
Circuit A14 also supplies power to the contact sides
of the Automatic Shut Down (ASD) relay and fuel
pump relay.
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well its fixin to go on the scanner :)
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I don't think you need a scanner at this point. Just check the wiring to determine why the relay is not being activated. Looks like you are pretty close to fixing it. If the FP relay is working, that would mean the computer is providing the ground so you don't need to worry about that any more.
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:clap: :dance: :clap: :dance: :clap: :dance: :clap: :dance: :clap: :dance: :clap: :clap: :dance: :clap:
found a broke wire :brick:
i still have an idle/miss issue.We check with the scanner to see if any of the cyl were missfiring but none of them were and i have no code's.
It happens while driving as well.when i unplug the IAC it still surges.
(http://i230.photobucket.com/albums/ee313/andrew383/jeep/th_MOV01898.jpg) (http://s230.photobucket.com/albums/ee313/andrew383/jeep/?action=view¤t=MOV01898.flv)
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you're not still running that SD coil are you?
put the stock coild back on and regap the plugs to 0.035 and see if its still there
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Glad to hear you got it running again.
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:clap: :dance: :clap: :dance: :clap: :dance: :clap: :dance: :clap: :dance: :clap: :clap: :dance: :clap:
found a broke wire :brick:
i still have an idle/miss issue.We check with the scanner to see if any of the cyl were missfiring but none of them were and i have no code's.
It happens while driving as well.when i unplug the IAC it still surges.
so was the wire going to the ASD? where was it broken? glad to hear you got that part sorted out. Now you just have to solve the misfire, i'm sure you'll figure it out soon.
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ive swapped coils.wires,plugs,cam/crank sensors. im out of ideas now.When we scanned it all cyl's were firing.Whatelse could it be?
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when you put the scanner on it - was it one that showed the cam and crank waveforms? also, were you monitoring the fuel pressure? You said that no cyls were misfiring - if that is indeed the case then it would lead to a fuel delivery issue, whether is from sensors (MAP, TPS) or the fuel system itself (fuel pump, regulator, injectors or injector wiring maybe) - can you determine if it is on one of the cylinders or not? (try to take one wire off at the time and see if there are no changes when you rev it then it could be the injector on that cyl) - you might want to also visually check the plugs and see if one is not looking healty.
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ill get it back on the scanner tommorrow,but im not sure it can the read the wave's between the cam and crank.
Ill also run it by the dealer to check the FP again.
What i did do is disconnect each injector and it still had the miss.I disconnected 2 at a time and it still missed.When i unplug the IAC,either o2's,TPS,or MAP it still miss's,plugs were changed along with cap and rotor.
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ill get it back on the scanner tommorrow,but im not sure it can the read the wave's between the cam and crank.
Ill also run it by the dealer to check the FP again.
What i did do is disconnect each injector and it still had the miss.I disconnected 2 at a time and it still missed.When i unplug the IAC,either o2's,TPS,or MAP it still miss's,plugs were changed along with cap and rotor.
i was thinking more on the line of looking at the waveform and see if you get any misses in signal. you did it right unplugging the injectors, the only thing you don't cover in that case is if one of them leaks. I would also check the ignition advance (not that you can adjust it but to make sure it's correct) - not sure if you can do that with the scanner but a strobe light would do. check the output of the MAP and i did have a misfire like problem (it would idle rough and stumble when accelerating) and in that case it turned out to be the TPS. good luck, but at least you got it running.
also, i was asking where was the broken wire?
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pull the injectors again, and make sure you didnt roll one of the o rings when you put them in....lil bit of dielectric grease on the o ring should help it slide in
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well while looking on the scanner the timing would jump around between 8* and 20*ish when it would miss.
Ive got a new TPS thats going in tommorrow hoping to solve the high idle problem.The way the tach drops every few miss's leds me to think its a crank.cam sensor??I dont have my hayne's in front of me but whats the test for the MAP?Ive searched around a bit but cant find a test procedure.
I can still beat on it pretty good without any problems and it runs fine aside from the miss,but the Exhaust has a weird smell to it.
The broke wire was a red wire going from the PDC to a (factory)splice in the harness next to the batt and i think came from the start/run circuit.
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pull the injectors again, and make sure you didnt roll one of the o rings when you put them in....lil bit of dielectric grease on the o ring should help it slide in
never had them out,waitin on you to look at that fuel rail in the attic :wall:
i have moved the injectors some when trying to pull the wires off the tho
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well while looking on the scanner the timing would jump around between 8* and 20*ish when it would miss.
that could be the crank, but not sure. the map (this is from memory so don't take it as a sure thing) should be around 0.65 at idle and 4.65 when you have the contact on and engine not running, from there it should vary between those 2 as you accelerate, if you suddenly open the throttle full would go to max and when you decelerate would go below the min (more vacuum due to higher rpm and closed throttle). i guess you have no codes at this point - you might have another bad wire too. I can't remember if you changed your tb - if you did you should throw in the old one just for a test.
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does the ECU only read the map during closed loop mode or no? I know his miss happens no matter what temp the motor is at, and also at all engine RPMs, and throttle positions.
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diff between open and closed loop is that in closed loop uses o2 sensor input to adjust afr. all the other inputs are used in both instances.
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well it seems to be day to day with this thing now.I went to load it up on the trailer yesterday for aride at it didnt want to go.IT had ran fine all morning but it started to break up in higher rpm's 3K+ and would die.Putting fuelin the intake did little help.So i left it at home,came back tried to start and its a no go.We pull the jeep around the yard back to to the front and while we were pullin i tried to start it but still nothin.
One thing to note is while trying to pull start it (4lo,1st)the rpms came up to about 1000 and even tho it wasnt running it still had that miss in it as i could see it on the tach and also hear it.So that leads me to believe that its not fuel related.
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it's either you lose power somewhere or one of the sensors has misses - but from another thread here, the guy had this problem where the tach would suddenly go to zero and it turned out to be oil in the distributor which was affecting the cam sensor - but since you replaced that already maybe it's your crank sensor (unless as i mentioned before you lose power somehow - could be another bad wire like the one you found).
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well i wheeled it both days this weekend and it did fine but still has a miss and idle's at 1500rpm+.I replaced the TPS but it didnt fix it.Ive "readjusted" the IAC 3 times now but it always ends up with a high idle.
Im taking the inspection cover off the trans tommorrow and going to check the 8 spots the crank sensor gets its mark from.
On a sad note a trashed not 1 but 2 tires this weekend :brick: but had fun doin it :lol:
candy for ya 8)
(http://i230.photobucket.com/albums/ee313/andrew383/jeep/6460_144720567348_547052348_3762533.jpg)
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well i pulled the inspection cover on the trans to inspect the notches in the flywheel for the crank sensor and they were all clean and there was no other obstruction's on it.
I spray some cleaner in the distributor,but its fairly clean.
The problem i had where it wouldnt rev over 3500 rpm was fixed by putting the stock coil back on :brick:
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lol, i told you about that coil....its designed to be run with their ignition parts...
you need to have a Fuel pressure gauge on it and watch the pressure and see if it drops while you are driving it....
I know i still havent checked that fuel rail i have....i promise i'll let you know, works been crazy this week.
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ive ran that coil for almost a year now without issue's :naughty:. The coil requires spiral wound core wires which i have there just not the live wires.
i do have 1 wire thats stock on there cause one ofthe other wires pulled apart and ive yet to crimp the end back on.