4bangerjp.com
General Forums => The Mess Hall => Topic started by: countryboy15 on January 25, 2010, 05:27:46 AM
-
What all comes off the 2.5 L throttle body when swapping to the 4.0L throttle body? I plan on doing the swap this weekend but I just want to make sure I know what to take off the 4.0 L throttle body and replace with the 2.5 L throttle stuff. I don't know much about this type of stuff, and I figured I might as well swap to the 4.0 L throttle body since I have the part sitting on my wrecked jeep in my backyard. Thanks for any help you can give me.
-
Take the IAC off the old one. Might as well swap the tps too since you know the one on your 2.5 is working.
Make sure you get a new TB gasket before you start the process.
-
Be sure to swap the IAC housing, it's usually attached to the TB with 4 tamper-proof torx.
Are the two TB's similar as far as the MAP sensor attachment? '91-'95 is different from '96-'04.
-
My good jeep is '91 models along with the wrecked jeep in my backyard.
-
I broke two torx bits already while trying to remove the throttle position sensor from both the 2.5 L and 4.0 L throttle bodys, any suggestions on how to do this without breaking anything else including the bolts holding it on.
-
penatrating oil to loosen em up a bit.
-
You can try a good penetrating spray like PB Blaster, but I think they are still prone to breakage if seized.
Let me know if you need anything, I've got a bunch of 2.5L, 4.0L, and 62mm throttle bodies, sensor bolts, sensors, etc.
-
The small torx use locktite so you can heat them up a little and they should break free,
-
I did the swap and now jeep wont start. It is turning over, when I put the pedal to the floor it just catches and jumps then immediately stops.
-
riGHT AFTER i DID THE SWAP IT STARTED. tHEN I KILLED IT TO CHANGE THE RADIATOR FLUIDS. aFTER i DID THAT iT STARTED BUT i NOTICED there was a clunking vibration coming from motor. I killed it to add more fluids, but after it didn't start how much more details are needed.
-
you either unplugged something by accident or maybe the tps got damaged during the swap. check methodically all the connectors
tps
map
cps
camshaft position sensor
ignition coil
iat
as well as map vac line.
and a question, it won't stay at idle or it would die even with the throttle open?
-
IT bearly catches a spark with the pedal to the floor, but won't keep going. It would not start with me pushing the pedal to the floor. I am going to try and start it again today, if it dont I am going to check everything you said to. I couldn't get the TPS off during the swap so I left it on, even when I PUT WD-40 on it(I didn't come back to this website until I had reinstalled the 4.0 L throttle body .
you either unplugged something by accident or maybe the tps got damaged during the swap. check methodically all the connectors
tps= Throttle position sesnsor(right?)
map= map sensor (does a '91 2.5 L have a map sensor)
cps= is what?
camshaft position sensor= where is this located
ignition coil
iat= what is this?
as well as map vac line. does a '91 jeep 2.5 have the map sensor as well as map sensor? if so where would I FIND this located at?
-
A '91 2.5L does have a MAP sensor, it's located on the firewall above the valve cover, has a vacuum line and electrical connection leading to it.
Did you swap over the IAC housing (idle air control)? It's on the passenger side of the throttle body and the only thing attached with 4 torx or tamper-proof torx bolts. This housing needs to be swapped over as the 2.5L housing has a smaller bore than the 4.0L housing. If you attached the 2.5L IAC to the 4.0L IAC housing then there is too much air moving past the IAC plunger. (The IAC housing may have 2.5L or 4.0L embossed on the outside).
CPS is commonly the crank position sensor, it's located on the driver's side of the bellhousing just behind the exhaust manifold. There is also a camshaft position sensor in the distributor but it doesn't commonly fail.
TPS is the Throttle Position Sensor and is attached to the front of the throttle body.
-
iat = intake air temperature sensor - i don't think would make your engine not run at all (from what you are saying that's the case right now).
i'm leaning towards tps if everything else is plugged in properly. I would also check the map sensor vac line (see Bounty's post for explanation where it is located), the map sensor connector and the tps connector - these are things that you might have left unplugged and can [to a certain extent] cause the problems you describe
-
I'm working on this today. Got one of Bounty hunters fancy TB and spacer kits. Got the manifold ground out and unfortunately I realized that I don't have the security torx bit that I need for the IAC housing, so it's off to the store to find one.
-
IT bearly catches a spark with the pedal to the floor, but won't keep going. It would not start with me pushing the pedal to the floor. I am going to try and start it again today, if it dont I am going to check everything you said to. I couldn't get the TPS off during the swap so I left it on, even when I PUT WD-40 on it(I didn't come back to this website until I had reinstalled the 4.0 L throttle body .
Take the not starting part back, IT started this morning but not last night, so my 2 cents is something is going out. I know it definitely isn't the starter changed that last week. ANY Ideas?
Also THe clunking type of vibration was still there this morning. THis morning when I got it started the idle speed is at 1000 rpm in neutral, I pressed the clutch and the idle speed went to about 1500 rpms, would the 4.0 L throttle position sensor do this?
Also what size torx bit fits the small torx bolts on the throttle body? The reason I ask I broke 3 different sized torx bits, a T-15H, T-20, and a T-20H.
I did swap the IAC, so if this is it, what to do?
ALSO I cant get the 4.0L TPS or the 2.5L TPS off, but I have yet to try applying heat to the torx bolts yet. Could the 4.0 TPS be the problem?
-
ALSO I cant get the 4.0L TPS or the 2.5L TPS off, but I have yet to try applying heat to the torx bolts yet. Could the 4.0 TPS be the problem?
It could be the problem if it is bad. The 2.5L and 4.0L use the same TPS.
-
I am going to have to change it when I get the time to.
-
Just throwing this out there but when I swapped on my 4.0 TB, I had never previously read anything about swapping over sensors :confused: Either that or I did and flat out forgot. I've never had a problem though with the 4.0 sensors on my motor... I did get mine off a like 96 or 97 Cherokee. Idle has always been the same and I've never had any weird issues....
-
Take the not starting part back, IT started this morning but not last night, so my 2 cents is something is going out. I know it definitely isn't the starter changed that last week. ANY Ideas?
Also THe clunking type of vibration was still there this morning. THis morning when I got it started the idle speed was at 1500 rpms immediately than gradually went down to 1000 rpm in neutral, would the 4.0 L throttle position sensor do this?
Also what size torx bit fits the small torx bolts on the throttle body? The reason I ask I broke 3 different sized torx bits, a T-15H, T-20, and a T-20H.
I did swap the IAC, so if this is it, what to do?
ALSO I cant get the 4.0L TPS or the 2.5L TPS off, but I have yet to try applying heat to the torx bolts yet. Could the 4.0 TPS be the problem?
-
YJ 4.0L tps P/N: 5234904
YJ 2.5L tps P/N: 2264 270
they are different
i used the 2.5L one when i did mine and had no issues
I didn't measure them though, i'll do that later tonight and will post back (i think it's a resistive pot - just a gut feeling).
-
seems to run good but there is a clunking type vibration when idling, any ideas on how to get rid of this?
-
seems to run good but there is a clunking type vibration when idling, any ideas on how to get rid of this?
i don't think the clunking has anything to do with your throttle body swap
-
i don't think the clunking has anything to do with your throttle body swap
i dont think it does either but I didnt want to start a new thread if the clunking vibration isnt nothing. i just never noticed it before the swap.
-
i dont think it does either but I didnt want to start a new thread if the clunking vibration isnt nothing. i just never noticed it before the swap.
i understand, i just don't know of anything that can be related so it would start right after a t/b swap - or at least i can't think of anything. where is it coming from?
EDIT: is your idle lower?
-
It feels like it is coming from the motor.
The idle goes up to 1500 rpms right off the start then will graually work back down to a little under 1000 rpms.
Thanks for all the help.
-
It feels like it is coming from the motor.
The idle goes up to 1500 rpms right off the start then will graually work back down to a little under 1000 rpms.
Thanks for all the help.
you'll have to pinpoint it better, but just as a general guess since this is common in our Jeeps i'd say it's a hydraulic lifter or (less likely) a loose or broken bolt on your exhaust header.
1000 rpm is high for idle unless you have an auto (even then i think it's more like 900 but the guys with an auto should confirm that as i'm not really sure). I'm going to measure that tps and see if they're really different, not just the part numbers.
-
Might want to check if it's just an air leak. Take a propane torch (unlit) and spray propane around the base of the TB. If that increases the idle, then you have a leak.
-
I
you'll have to pinpoint it better, but just as a general guess since this is common in our Jeeps i'd say it's a hydraulic lifter or (less likely) a loose or broken bolt on your exhaust header.
1000 rpm is high for idle unless you have an auto (even then i think it's more like 900 but the guys with an auto should confirm that as i'm not really sure). I'm going to measure that tps and see if they're really different, not just the part numbers.
It gets to about 700-800 rpms idling, but it takes a while.
-
I
It gets to about 700-800 rpms idling, but it takes a while.
the tps seems to be an active device not just a pot so i can't measure it - i need to use a 5v power supply but my lab p/s is out for repairs so i need to wait until it comes back. You need a T20 to take the tps off, i had no trouble taking them out, you need a good torx though - if you put the torx in and tap slightly on the end of it should help losen the bolts. You can also cut a slit across the bolt with a dremel cutting wheel and make it wide enough for a large flat screwdriver, that would most likely do it - aas far as hear, not sure, i'd be worried not to damage the tps. On a guess since the part numbers are different i would guess the output is also different so better use the one off your 2.5L - should go down to 750 to 800 rpm fairly quick, my guess is the tps that makes the difference.