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General Forums => The Mess Hall => Topic started by: jfrabat on October 31, 2011, 03:29:44 PM

Title: Some engine issues- Need help
Post by: jfrabat on October 31, 2011, 03:29:44 PM
Hey, guys, I need your help!

When I took the Jeep out on my last outing, I felt it a bit underpowered (well, more than ussual).  I remember that before I could accelarate up a hill near my house in 3rd gear, yet now, the speed is slowly drained by the same hill.  I also noticed that if I shut the Jeep off and then try to restart, I have a hard time.  If I let it rest a bit, it then starts up just fine.  Any ideas as to what I could check for this?  I am thinking there may be some gunk in the engine (before my trip to CR about a month or so ago, the plugs were stuffed with what my dad described as "mud").  As a result, I am also starting to look as my injectors as suspect...  I also had some issues with the spark for Cyl 1 jumpint from the top of the distributor boot to the AC Compressor (have not chequed it again, but I did change wires).  So I am thinking about changing out the injectors (I changed them about 4 or 5 years ago), maybe put a new rail in there (already got one, so might as well), check the FPR (if you see my last post, pressure seemed a bit high), check the return line to be sure there are no obstructions there, maybe put a checkvalve to be sure the fuel is not going back through the pump, and changing plugs and wires.  Should I look at anything else?  I already replaced all the vacuum lines (the power issue came up BEFORE this, so this is not the cause) and cleaned the air filter (it was not that dirty anyway).

Any help is greatly appreciated (including the best place to get good quality injectors that are balanced at a reasonable price)...

Felipe
Title: Re: Some engine issues- Need help
Post by: jfrabat on October 31, 2011, 03:35:35 PM
Oh, and one more question; what could be causing me to go through Oil Pressure Sending units every 6 months or so?  I am tired of changing this...  And about every 6 months or so, they die on me (granted, I abuse mine with lots of mud and water, but STILL, they should at least last one year!)
Title: Re: Some engine issues- Need help
Post by: sharpxmen on October 31, 2011, 03:49:01 PM
Felipe,
if your plugs had something "mud" like looking on them i would do a compression test. As far as a check valve, that should be ok but that doesn't explain why it starts better if you let it sit for a while. Re: your pressure bleeding - can't remember if you fixed your gasoline smell, there are 4 external o-ring quick connect fittings that can also cause this issues, 2 are at the injector fuel rail and 2 are on the frame at the fuel pressure and return lines on the driver side right below the firewall, if any of those o-rings leak (on the pressure side) you would have the pressure bleeding out of the rail, also if any of these 4 leak (on the pressure and return lines) you would have fuel smell. You should also inspect the FPR o-rings, either large or small one not sealing properly would cause the pressure to bleed. Also make sure your pressure is not too high, like i mentioned before should not be higher than 45psi, so have a look at that as well. The PCM temperature sensor is another place i would check (and this can be somewhat related to letting it rest for a bit and would start up ok) and possibly the o2 sensor (could be running to rich due to bad signal from o2).

oil pressure sender - just install a mechanical one, you'd be glad you did (way more accurate and won't fail on you as often) - the only thing i can think of in regards to failing is that they are not quality sensors, they are sealed so it shouldn't matter if they are underwater the whole time unless it's the electrical contact on the terminal that causes the issues (but it would not damage the sensor so from what you are saying that's not it).
Title: Re: Some engine issues- Need help
Post by: Jeffy on October 31, 2011, 03:49:37 PM
'mud' would suggest water and oil.

Not sure about the oil pressure sender.  I replaced mine with an OE from a pulled engine.  The senders are cheap for the most part so I'd think that they're jsut failing because of that.  You could replace it with an aftermarket sender if you wanted to.
Title: Re: Some engine issues- Need help
Post by: jfrabat on October 31, 2011, 04:57:53 PM
My theory on the mud is that, on the last run some months ago before I took the Jeep back to Panama, there was a vaccuum leak, which is why I replaced all the lines with silicone ones.  My guess is that the engine ingested either dirt (from the air being sucked up), mud (when crossing mud pits), or both, and this got the whole combustion chamber dirty.  I am planning on doing compression tests, and also checking how well it is holding compression (I have both testers; the one that measure compression regularly, and the one you use with the air compressor, so I will use both).

But the reason I am considering changing the injectors is that they could also be causing the Fuel Pressure to drop if they are leaking into the combustion chamber.  As for the pressure, i am not sure what to do; I dont completely trust the fuel pressure testing unit I got, and I quoted a new one locally, and the cheap ones run over $400, so I am not buying one of those...

Anyway, I will start by removing the fuel rail and looking at the O-Rings in both the rail itself and the FPR.  I will also change the O-Rings in the frame that Sharp mentioned...  I may also just get rid of the cat altogether in case that is acting up as well (I dont have to pass any inspections).

Felipe
Title: Re: Some engine issues- Need help
Post by: Jeffy on October 31, 2011, 04:59:04 PM
Hmm, I don't think mud would be around for long in the combustion chamber.
Title: Re: Some engine issues- Need help
Post by: sharpxmen on October 31, 2011, 05:14:04 PM
you can check the injectors to see if they leak by taking out the fuel rain with the injectors on it, create pressure (without attempting to start the engine) and having the tips of the injectors in some small plastic bottles (to avoid gas being sprayed on the engine, plugs, etc and cause a fire, sometime you get the odd spark when the key is switched on) - if you see drops coming out at the injector tip then they leak.
Title: Re: Some engine issues- Need help
Post by: jfrabat on October 31, 2011, 05:30:01 PM
Hmm, I don't think mud would be around for long in the combustion chamber.

Depends how much got in there in the first place, I guess...  But for now, I'll start simple and work my way to the more complicated.  For now, O rings and tests will be done first, along with a plug change (and probably the rotor, cap and wires, since I already got them).
Title: Re: Some engine issues- Need help
Post by: grumpygy on October 31, 2011, 05:32:06 PM
Coil could be the reason it starts easier after it cools down.
Title: Re: Some engine issues- Need help
Post by: jfrabat on October 31, 2011, 05:43:56 PM
Coil could be the reason it starts easier after it cools down.

That's a good point, but I changed it less than a month ago.  unless it suddenly died, I dont think it is the culprid.  Also, it acts up to start, but once it starts, it runs fine; the coil (I THINK!) would act up whenever it is hot (so it should act up AFTER it starts as well, right?)  Anyway, correct me if I am wrong, and thanks for the help!
Title: Re: Some engine issues- Need help
Post by: sharpxmen on October 31, 2011, 06:46:14 PM


 As for the pressure, i am not sure what to do; I dont completely trust the fuel pressure testing unit I got, and I quoted a new one locally, and the cheap ones run over $400, so I am not buying one of those...


all you need is a pressure gauge, one that you would use for air would work since is not permanent install and keep the hose/adapters from the current one. A 60 psi is preferred for better resolution but 100 would work just fine also - just need to match the fitting on it, most of them are 1/4'' NPT (pipe thread) for that size but you'll need to check yours - possibly use an adapter if you can't find a matching one. Use teflon tape to seal the thread and you're good to go.
Title: Re: Some engine issues- Need help
Post by: grumpygy on October 31, 2011, 08:27:08 PM
That's a good point, but I changed it less than a month ago.  unless it suddenly died, I dont think it is the culprid.  Also, it acts up to start, but once it starts, it runs fine; the coil (I THINK!) would act up whenever it is hot (so it should act up AFTER it starts as well, right?)  Anyway, correct me if I am wrong, and thanks for the help!

Stock or after market coil.   Not always will it act up, but you may notice a lack of power cause its not working right.  Just at start up it may take a little more to start.
Title: Re: Some engine issues- Need help
Post by: sharpxmen on October 31, 2011, 08:50:54 PM
Felipe, how's the battery voltage?
Title: Re: Some engine issues- Need help
Post by: jfrabat on November 01, 2011, 08:21:41 AM
Coil IS aftermarket; I have a spare one, so I will replace it and see how that goes (I'll keep the current one as a spare).  Battery was also fine (have not checked voltage, but the starter did not have any issues; I even started in 4L in 1st gear at one point).  I'll give the air PSI gauge a shot and see how that works...
Title: Re: Some engine issues- Need help
Post by: grumpygy on November 01, 2011, 06:54:50 PM
I threw back in a stock coil and my Problems went away.  It was not rated at the right Ohms for the stock ignition system.
Title: Re: Some engine issues- Need help
Post by: jfrabat on November 02, 2011, 09:11:19 AM
I threw back in a stock coil and my Problems went away.  It was not rated at the right Ohms for the stock ignition system.

I believe you; I have gone through 2 screaming demon coils and one accel, plus two cheap ones...
Title: Re: Some engine issues- Need help
Post by: Torch_Ind on November 02, 2011, 04:27:27 PM
I believe you; I have gone through 2 screaming demon coils and one accel, plus two cheap ones...

I had lots of issues with the stock style replacement coils. what I found was the problem was the connection style of the plug. would always cause coil failure.

I went to the old style coil with bolt on connections and haven't had any issues since

only prob I had was the connection end of the coil for the spark plug wire was opposite as the stock style one but the parts guys had cables to go to that style coil

http://store.prestoliteperformance.com/accel/accel-coils-accessories/superstock-high-vibration-coil.html (http://store.prestoliteperformance.com/accel/accel-coils-accessories/superstock-high-vibration-coil.html)

(http://store.prestoliteperformance.com/media/catalog/product/cache/1/image/370x/9df78eab33525d08d6e5fb8d27136e95/8/1/8140HV.jpg)
Title: Re: Some engine issues- Need help
Post by: jfrabat on November 03, 2011, 03:07:28 PM
Guys, just to check (so I don't screw up when I do the test), the process is as follows, right?


If I get any significant differences, I may run a leakage test, since I already got the tester... 

Anyway, if someone can confirm the process, I think I'll give this test a shot on Saturday...

Felipe
Title: Re: Some engine issues- Need help
Post by: aw12345 on November 03, 2011, 04:29:12 PM
When you do a leak down test make sure to disconnect all the crank case ventilation hoses. Other than that to check engine mechanical condition a leak down tester is a much better tool to use than a compression tester. Just a bit more work
Title: Re: Some engine issues- Need help
Post by: jfrabat on November 03, 2011, 04:54:03 PM
When you do a leak down test make sure to disconnect all the crank case ventilation hoses. Other than that to check engine mechanical condition a leak down tester is a much better tool to use than a compression tester. Just a bit more work

Which one is that?  the one that goes back to the filter box?
Title: Re: Some engine issues- Need help
Post by: sharpxmen on November 03, 2011, 07:02:39 PM
it will vent to the filter, i doubt you need to disconnect the hoses, there's no check valve at the valve cover.

your plan looks good.
Title: Re: Some engine issues- Need help
Post by: jfrabat on November 05, 2011, 07:08:17 PM
OK, guys, I'm stuck!  I took the jeep for a morning drive (minus the top) with the family, and it was running fine.  I then got it into the garage to do the compression test, and got all plugs out (they looked fine; I'll post pics later on).  For some reason (and yes, the thread is the correct size; it is not that!), I could not catch the threads of the plug holes with the compression tester on any of the cylinders.  I really dont get why I cant do this!  Anyway, while thinking about it, I took a look at the TB, and it was FILLED with gunk (pics of that also coming up), so I took it apart to clean it.  This is when I noticed that my TPS was cracked (and I accidentally finished the job of killing it - yet more of the pics loading up as I write).  Perhaps this is what was acting up, don't know...  So anyway, I cleaned it up, but now I need to buy a new TPS on Monday (IF I can find one locally!).  For now, the Jeep is sitting in the garage with no TB or plugs, as I still want to do the compression test just to see what it turns out...  I just put a rag over the TB opening, and another over the plug holes.  I may even take the oportunity to enlarge the intake manifold opening, but that kind of scared me a bit!
Title: Re: Some engine issues- Need help
Post by: jfrabat on November 05, 2011, 08:10:00 PM
Here's how the plugs looked when I pulled them (Cyl #1 is on the left; there is some faint dust one the #1 and #2 cylinders, which are the ones my dad described as having "mud" last time he pulled the plugs):

(http://i46.photobucket.com/albums/f138/jfrabat/Jeep/DSC08946.jpg)

By the way, I am using Champion RC12LYC plugs; can you guys confirm if these are the right plugs?  According to the Bosch book, these are a bit too cold (the comparable Bosch plug is, anyway) and Bosch recommended one step hotter for the Jeep...

Here's how the TB looked when I took it off:

(http://i46.photobucket.com/albums/f138/jfrabat/Jeep/DSC08947.jpg)

Had gunk both inside:

(http://i46.photobucket.com/albums/f138/jfrabat/Jeep/DSC08948.jpg)

(http://i46.photobucket.com/albums/f138/jfrabat/Jeep/DSC08952.jpg)

and outside...

(http://i46.photobucket.com/albums/f138/jfrabat/Jeep/DSC08949.jpg)

so I cleaned it and it ended up looking like this:

(http://i46.photobucket.com/albums/f138/jfrabat/Jeep/DSC08953.jpg)

(http://i46.photobucket.com/albums/f138/jfrabat/Jeep/DSC08955.jpg)

Unfortunately, I killed my TPS in the process (not sure, but I THINK it was already cracked, as it broke off WAY too easily):

(http://i46.photobucket.com/albums/f138/jfrabat/Jeep/DSC08951.jpg)

Still trying to figure out why the compression tester will not catch the threads on the plug holes...

Felipe
Title: Re: Some engine issues- Need help
Post by: sharpxmen on November 05, 2011, 08:33:59 PM
what's the hex size on the compression tester fitting, that migt bottom out in the plug holes before getting to the thread, there is usually an extender you can use in that case.

(http://i46.photobucket.com/albums/f138/jfrabat/Jeep/DSC08946.jpg)

1 & 2 look normal, not sure why 3 & 4 have nothing on, were they wet?
Title: Re: Some engine issues- Need help
Post by: jfrabat on November 05, 2011, 08:47:30 PM
what's the hex size on the compression tester fitting, that migt bottom out in the plug holes before getting to the thread, there is usually an extender you can use in that case.

(http://i46.photobucket.com/albums/f138/jfrabat/Jeep/DSC08946.jpg)

1 & 2 look normal, not sure why 3 & 4 have nothing on, were they wet?

No extender on this one; I think it may be the angle, but I'll give it another shot tomorrow...  I'm too lazy to do a leak down test (TDC is kind of a pain to do 4 times...).  #3 and #4 were not wet...
Title: Re: Some engine issues- Need help
Post by: sharpxmen on November 05, 2011, 09:30:30 PM
can you take a picture of the compression tester fitting.
you could be right about the angle
Title: Re: Some engine issues- Need help
Post by: grumpygy on November 05, 2011, 09:53:48 PM
Just as plugs come in different Sizes so do the Compression testers.  I would bet the tester is for larger plugs than you are using.  were there any adapters with the tester.
Title: Re: Some engine issues- Need help
Post by: jfrabat on November 06, 2011, 10:55:27 AM
Just as plugs come in different Sizes so do the Compression testers.  I would bet the tester is for larger plugs than you are using.  were there any adapters with the tester.

For some reason (and yes, the thread is the correct size; it is not that!), I could not catch the threads of the plug holes with the compression tester on any of the cylinders.

Thanks, Grumpy, but that is not the cause...

can you take a picture of the compression tester fitting.
you could be right about the angle

The problem is I got NO visibility in there to see what's going on when I put the tester hose in there...  Even in Cyl #3, which is the one I can look at the better, I cannot see what's going on!
Title: Re: Some engine issues- Need help
Post by: grumpygy on November 06, 2011, 06:54:54 PM
http://compression-tester-extension.salehugedeal.com/
Title: Re: Some engine issues- Need help
Post by: jfrabat on November 06, 2011, 08:18:27 PM
http://compression-tester-extension.salehugedeal.com/

That's more like what I need...  I have been trying to figure out how to use the leak down tester's hose for the compression test, but I cant figure out how to install a valve on that one...
Title: Re: Some engine issues- Need help
Post by: sharpxmen on November 06, 2011, 08:22:26 PM
That's more like what I need...  I have been trying to figure out how to use the leak down tester's hose for the compression test, but I cant figure out how to install a valve on that one...

i'm thinking that could be too long for cyl 1 and possibly 2 since you have the A/C compressor there.

try to wrap some electrical take around the fitting on the compressor so it will keep it centered in the spark plug hole (just how the socked does when you install the plugs) - i remember having to fiddle that fitting a bit to get it right on the thread so this could help.
Title: Re: Some engine issues- Need help
Post by: jfrabat on November 06, 2011, 08:30:46 PM
I am still trying to see if I can use the leak down tester hose instead...  By the way, here's a pic I managed to get of the compression tester trying to reach the threads on the plug hole, as well as a comparisson with the leak down tester:

(http://i46.photobucket.com/albums/f138/jfrabat/Jeep/DSC08962.jpg)

(http://i46.photobucket.com/albums/f138/jfrabat/Jeep/DSC08964.jpg)

Felipe
Title: Re: Some engine issues- Need help
Post by: aw12345 on November 06, 2011, 08:31:14 PM
what's the hex size on the compression tester fitting, that migt bottom out in the plug holes before getting to the thread, there is usually an extender you can use in that case.

(http://i46.photobucket.com/albums/f138/jfrabat/Jeep/DSC08946.jpg)

1 & 2 look normal, not sure why 3 & 4 have nothing on, were they wet?

Looking at the plugs I doubt that a serious lack of compression is your problem.
They all have good combustion. Have you tried the easiest thing of all a plain ole vacuum gauge? It tells quite a bit about engine condition with very little work.
Cylinder contribution is not a bad test either, use a tach and pull plug wires one at a time while the engine runs at about 2000 rpm and watch the rpm drop for each cylinder. Could be a bit of a electrifying experience but it gives you a pretty good idea of what is going on. If the cyl contribution and the idle vacuum is 19" or better with no needle fluctuation, then there is no need for doing a compression test.
Title: Re: Some engine issues- Need help
Post by: sharpxmen on November 06, 2011, 09:12:54 PM

(http://i46.photobucket.com/albums/f138/jfrabat/Jeep/DSC08964.jpg)


those are stupid short, no wonder you can't get it squared on the plug threads, you need an extender about as long as the plug so you have some control, the hose will never be straight as much as you are trying, it can be done but def harder than with a longer one.
Title: Re: Some engine issues- Need help
Post by: jfrabat on November 07, 2011, 04:45:48 PM
Well, i got me an extension for the compression tester; I'll see if I can hook it up tonight and report back.  I will also test vacuum (got me a new gauge today) and see how that's doing...  Also got the new TPS and IAC sensors today, so those are also going in tonight...  And the Performance Distributor ignition system should be here before the end of the week, so that's going in soon as well!  Anyway, I'll report back tomorrow with some results (hopefully!).
Title: Re: Some engine issues- Need help
Post by: jfrabat on November 07, 2011, 09:38:18 PM
OK, finally did the compression test.  It seems cyl #1 is a bit on the low side, but nothing to worry about (17% from the lowest reading to the highest)...  Could even be that I did not catch the thread properly (AC compressor is in the way).  Here are the readings:

Cyl #1 (119 PSI):

(http://i46.photobucket.com/albums/f138/jfrabat/Jeep/Piston1secondtake.jpg)

Cyl #2 (136 PSI):

(http://i46.photobucket.com/albums/f138/jfrabat/Jeep/Piston2.jpg)

Cyl #3 (140 PSI):

(http://i46.photobucket.com/albums/f138/jfrabat/Jeep/Piston3.jpg)

Cyl #4 (135 PSI):

(http://i46.photobucket.com/albums/f138/jfrabat/Jeep/Piston4.jpg)

Also took a vacuum reading; seems I may still have some issues in this department, as the idle vacuum is a bit on the low side.  Here's what the gauge read at idle (15 in Hg):

(http://i46.photobucket.com/albums/f138/jfrabat/Jeep/vacuumidle.jpg)

Here's how it read at 1,500 RPM's (18/5 in Hg):

(http://i46.photobucket.com/albums/f138/jfrabat/Jeep/vacuum1500rpm.jpg)

Also rechecked the Fuel Pressure with the new PSI gauge; Sharp, it seems we were both right.  Pressure is closer to what you reported, and it seems the old gauge was just off...  Here's the reading with the vacuum connected (37 PSI):

(http://i46.photobucket.com/albums/f138/jfrabat/Jeep/FPwithvaccum.jpg)

And without vacuum (44 PSI):

(http://i46.photobucket.com/albums/f138/jfrabat/Jeep/FPvacuumdisconnected.jpg)

Title: Re: Some engine issues- Need help
Post by: sharpxmen on November 07, 2011, 10:43:38 PM
fuel pressure is good, leave it as it is.

was the compression done warm engine or cold?

vacuum is low (as in higher than it should be, 18 or 19 is normal like Art said) given that the engine was warm - are you doing it at sea level or is it higher altitude - that also matters, the higher you are less vacuum you get.

EDIT: this is what i got on mine with the engine cold (but it was hot outside - not extremely, something like 30C), this was a retest, the first time around they were lower but not by much (10 psi), could have been that it was cooler outside.

1 - 155psi
2 - 155psi
3 - 140psi
4 - 160psi

i remember doing it after running the engine until it got to the temperature, can't remember exactly the results but it think it was somewhere in the 180s or so but can't tell for sure, i do remember that the difference with cyl 3 was not as much, it was still lower but closer to the other ones.
Title: Re: Some engine issues- Need help
Post by: aw12345 on November 07, 2011, 11:15:09 PM
You would prefer no more than a 10% spread between lowest and highest.
Would not hurt to do a leak down test between the lowest and highest cylinders to see what the difference between those 2 is. Again you would should for 10% or less difference.
Vacuum is kinda low could be due to the non stock cam. What running problem does the engine have? Lack of power but runs smooth, misfire or?
Sometimes comparing compression while idling and reving it up to say 2000 rpm and doing this to each cylinder gives you a good idea about valve opening / camshaft condition/ lifters collapsing
Title: Re: Some engine issues- Need help
Post by: sharpxmen on November 07, 2011, 11:57:42 PM
Vacuum is kinda low could be due to the non stock cam.

yeah that could be one reason, good catch.

Title: Re: Some engine issues- Need help
Post by: jfrabat on November 08, 2011, 08:15:00 AM
I guess I forgot to mention some background info...  Compression test was done dry only, and since I had taken engine apart 2 days prior (but could not run the test due to tje tester issues), the engine was cold (as in there was no oil to help in the compression).  I did not have time to put the TB back together in time to start the engine prior to running the test, so I just went for it as it was.  Its a good point you make abput the vacuum being low due to the cam...  Just in case, though, I am thinking of plugging all the vacuum outlets.except the MAP and retesting to be sure.  Regarding the compression of cyl 1, it could also be that the seal of the tester was not up to par; I feel I could not tighten the tester as well as I did on the other 3 cylinders because of how difficult it was to get the tester in there.  IIRC, I did not even get a full turn in...  so I am not too worried about it.  Oh, and there were no misfires or anything; I just felt it lacked power.  In fact, going up a hill near my house, I normally cam accelarate in third, but now I could not even maintain speed.  But then on Saturday when I took a ride with the top off with the family, it felt fine again.  I am thinking it could have been the broken TPS, to be honest...
Title: Re: Some engine issues- Need help
Post by: jfrabat on November 09, 2011, 12:39:24 PM
Received the PD Ignition today, so new coil, Live Wires, rotor and cap are going in today.  Looks like I'll be wheeling on Saturday!
Title: Re: Some engine issues- Need help
Post by: jfrabat on November 22, 2011, 07:25:29 AM
Well, it took a while (too much work, thankfully), but I finally got the PD ignition system in place.  When I took out the old distributor cap, I think I may have stumbled into my power loss issue; you see, the old cap had corrossion on 3 of the 4 post, and 2 of them had grooves in them as well.  Here are some pics:

(http://i46.photobucket.com/albums/f138/jfrabat/Jeep/DSC09231.jpg)

(http://i46.photobucket.com/albums/f138/jfrabat/Jeep/DSC09234.jpg)

(http://i46.photobucket.com/albums/f138/jfrabat/Jeep/DSC09238.jpg)

(http://i46.photobucket.com/albums/f138/jfrabat/Jeep/DSC09240.jpg)

Now, when I put the new system on, I had a bit of a hard time starting the Jeep the first time, so I took off a boot and checked the spark.  Well, not only was there spark, but the jeep started on 3 cylinders, so I put it back on and it fired right off...  Idled better also!
Title: Re: Some engine issues- Need help
Post by: jfrabat on November 22, 2011, 01:32:31 PM
I am DEFENETLY doing something wrong...  During my lunch break, I picked up the Jeep in my house to take it to a brake shop to have the rear brakes fixed (I am having issues with the eBrake), and, not even a mile away from home, the Jeep starts acting up.  So, AGAIN, it seems my PD Screaming Demon is dying on me...  WHAT THE HELL!?  It's EXACTLY the same symptoms as it has done in the past.  It starts up fine, then when it warms up, it starts to sputter until it eventually dies.  I drive it back to the house and switched cars again.  I still have the previous coil (plus 2 more as spares), so I'll just put a cheapo coil back on and see how it drives, but this is REALLy starting to get on my nerves. 

Anyway, do you guys have ANY ideas as to what could be going on with my Jeep and the PD Coils????

Felipe
Title: Re: Some engine issues- Need help
Post by: sharpxmen on November 22, 2011, 02:08:24 PM
I am DEFENETLY doing something wrong...  During my lunch break, I picked up the Jeep in my house to take it to a brake shop to have the rear brakes fixed (I am having issues with the eBrake), and, not even a mile away from home, the Jeep starts acting up.  So, AGAIN, it seems my PD Screaming Demon is dying on me...  WHAT THE HELL!?  It's EXACTLY the same symptoms as it has done in the past.  It starts up fine, then when it warms up, it starts to sputter until it eventually dies.  I drive it back to the house and switched cars again.  I still have the previous coil (plus 2 more as spares), so I'll just put a cheapo coil back on and see how it drives, but this is REALLy starting to get on my nerves. 

Anyway, do you guys have ANY ideas as to what could be going on with my Jeep and the PD Coils????

Felipe

are you sure it's the coil and not the signal from the PCM, and if the latter could be the issue then i would think maybe the crank sensor could be the problem (acting up once it's warming up). If that's not it and it runs fine with a stock coil then i have no idea other than you got bad luck with the PD stuff but it's very unlikely that 3 of them to do the same thing though.
Title: Re: Some engine issues- Need help
Post by: jfrabat on November 22, 2011, 03:09:22 PM
are you sure it's the coil and not the signal from the PCM, and if the latter could be the issue then i would think maybe the crank sensor could be the problem (acting up once it's warming up). If that's not it and it runs fine with a stock coil then i have no idea other than you got bad luck with the PD stuff but it's very unlikely that 3 of them to do the same thing though.

But how come it only happens with the PD coil?  I did notice that there is something loose (well, not loose, but it not solid) in the connector from the ECU to the coil...  Not sure that is the cause, but again, why only with the PD coil?  I could swap the PCM out (I have a spare one) and see what happens... 

I have an old crank position sensor that I could swap out and test, but again, why does it act up only with the PD coil?
Title: Re: Some engine issues- Need help
Post by: neale_rs on November 22, 2011, 03:21:18 PM
Impedance mismatch (whatever that means!).  I would just use the stock coil and be done with it, it's not so bad.
Title: Re: Some engine issues- Need help
Post by: jfrabat on November 22, 2011, 03:31:43 PM
I talked to PD today, and they say it sounds like a bad ground.  They told me to scratch the paint off the distributor to create a better ground, so I'll give that a shot tonight.  He said to use a screw driver, but I will probably just sand it down, and take the opportunity to sand the mounting as well to insure the best possible contact.  We'll see how that goes...  
Title: Re: Some engine issues- Need help
Post by: grumpygy on November 22, 2011, 05:28:45 PM
Impedance mismatch (whatever that means!).  I would just use the stock coil and be done with it, it's not so bad.

That was my problem got a new performance coil and the Impedence was wrong.  Changed back to the stock type of copild and its running great.
Title: Re: Some engine issues- Need help
Post by: sharpxmen on November 22, 2011, 09:18:24 PM
I talked to PD today, and they say it sounds like a bad ground.  They told me to scratch the paint off the distributor to create a better ground, so I'll give that a shot tonight.  He said to use a screw driver, but I will probably just sand it down, and take the opportunity to sand the mounting as well to insure the best possible contact.  We'll see how that goes...  

huh?  :yikes:

they are certainly mixing medication and alcohol - wtf does the ground on the distributor has to do with the spark on a fully electronic ignition system triggered by the crankshaft position sensor, even the sensor in the distributor (cam position sensor) has nothing to do with the spark in this case (the spark is distributed by the cap, not a 4 coil setup) and has its own ground wire - the distributor can be completely groundless, there are no points or anything related to the spark in there other than the mechanical positioning of the rotor so it sends the spark to the corresponding cylinder.

You'd be wasting your time, i would call and tell them exactly what i said above, this is 100% accurate and not a guess as per PCM (but then again not related to the spark but injector opening sequence):

CAMSHAFT POSITION SENSOR
The Powertrain Control Module (PCM) supplies 8
volts to the camshaft position sensor (in distributor)
on circuit K7. Circuit K7 connects to cavity 7 of the
PCM.
The PCM receives the camshaft position sensor signal
on circuit K44. Circuit K44 connects to cavity 44
of the PCM.
The PCM provides a ground for the camshaft position
sensor signal (circuit K44) through circuit K4.
Circuit K4 connects to cavity 4 of the PCM.
Title: Re: Some engine issues- Need help
Post by: Jeffy on November 22, 2011, 09:43:58 PM
I recommend emailing them so you don't have to explain it all over again.
Title: Re: Some engine issues- Need help
Post by: jfrabat on November 23, 2011, 07:04:54 AM
I talked to PD today, and they say it sounds like a bad ground.  They told me to scratch the paint off the distributor to create a better ground, so I'll give that a shot tonight.  He said to use a screw driver, but I will probably just sand it down, and take the opportunity to sand the mounting as well to insure the best possible contact.  We'll see how that goes...  

Meant coil, not distributor...  Apparently, the paint over the metal part does not allow for a good ground to the mount, so they recommended I scratch that paint so that a good ground is possible.  Made sense to me when they explained it, so I'll give it a shot.
Title: Re: Some engine issues- Need help
Post by: sharpxmen on November 23, 2011, 08:46:01 AM
Meant coil, not distributor...  Apparently, the paint over the metal part does not allow for a good ground to the mount, so they recommended I scratch that paint so that a good ground is possible.  Made sense to me when they explained it, so I'll give it a shot.

i don't know why the coil would need ground, it has 12v permanently as long as the engine rotates from the automatic shutdown relay, the PCM gives it ground when it needs to fire a spark - maybe their coil is different and needs a ground (in that case i would wonder why is it painted where it should make contact). Keep us posted.
Title: Re: Some engine issues- Need help
Post by: jfrabat on November 23, 2011, 10:01:23 AM
i don't know why the coil would need ground, it has 12v permanently as long as the engine rotates from the automatic shutdown relay, the PCM gives it ground when it needs to fire a spark - maybe their coil is different and needs a ground (in that case i would wonder why is it painted where it should make contact). Keep us posted.

As I said, I'll give it a shot and see how it happens.  I got plenty of other coils if this one does not work, but now that you mentioned it, I used to have a coil where the entire metal part was encased in plastic, so I dont see why paint should be an issue (it did have brass where it bolts to the engine, though).
Title: Re: Some engine issues- Need help
Post by: sharpxmen on November 23, 2011, 11:58:46 AM
As I said, I'll give it a shot and see how it happens.  I got plenty of other coils if this one does not work, but now that you mentioned it, I used to have a coil where the entire metal part was encased in plastic, so I dont see why paint should be an issue (it did have brass where it bolts to the engine, though).

actually it makes sense that it needs ground (for the secondary coil, the primary is the one that gets it from the PCM), my bad.
Title: Re: Some engine issues- Need help
Post by: jfrabat on November 26, 2011, 04:11:12 PM
actually it makes sense that it needs ground (for the secondary coil, the primary is the one that gets it from the PCM), my bad.

Well, its not the groun.  I sanded both the coil as well as the mount to insure a good ground, but the engine died on me again.
Title: Re: Some engine issues- Need help
Post by: grumpygy on November 26, 2011, 05:30:13 PM
Well, its not the groun.  I sanded both the coil as well as the mount to insure a good ground, but the engine died on me again.

So have you tried a stock coil yet, also do you have a stock Distributor.

  Keep asking cause I would like to get this kit for my 74 cause it looks like and easy upgrade.
Title: Re: Some engine issues- Need help
Post by: dwtaylorpdx on November 26, 2011, 10:59:57 PM
This is acting EXACTLY like my plugged tank filter problem, very
intermittent and went away if you let the thing idle of sit for 5 or 10 minutes.
The pump would overheat and lose volume, it would show fine on a
gauge but not at power going down the road.

It was worse at low fuel levels and hot air temps...

Dave

Title: Re: Some engine issues- Need help
Post by: grumpygy on November 27, 2011, 11:45:37 AM

Meant 94 in the above post. :brick:
Title: Re: Some engine issues- Need help
Post by: jfrabat on November 27, 2011, 01:09:28 PM
In my case, it is defenetly the coil.  I put the OEM type back in, and it firednright up without issues...  I am calling PD again tomorrow.  This is the second time this happens with their Screaming Demon coil!  By the way, the fuel filter waschanged about 3 months ago along with the fuel pump and prefilter.
Title: Re: Some engine issues- Need help
Post by: dwtaylorpdx on November 28, 2011, 12:01:45 AM
Ah cool Last thing, did you check to see if the tank had shrunk like mine and was pushing on the bottom of the pump? (It was the primary problem, I discovered the other stuff after I pulled the tank... :)

Wonder if your seeing a weak circuit in the ECU that cant drive the higher capacity coil?

Dave

Title: Re: Some engine issues- Need help
Post by: jfrabat on November 28, 2011, 05:48:26 AM
Ah cool Last thing, did you check to see if the tank had shrunk like mine and was pushing on the bottom of the pump? (It was the primary problem, I discovered the other stuff after I pulled the tank... :)

Wonder if your seeing a weak circuit in the ECU that cant drive the higher capacity coil?

Dave




Yeah,remember I had to changr fuel pumps 3 months ago...