Jeep wont Start... (HELP)

[Punisher]

Hey Guys!! long time no see... Just been so busy at work and had no internet. But I'm back. the other day I was drivin to work and all of the sudden the jeep just shut down. I had it towed to a friend's and I replaced the "crankshaft position sensor" and its trying to start but wont stay running but as soon as I push the pedel it just keeps turing over without a kick over until I let the pdel go and its wants to kick again like its not getting gas but I know its getting gas cuz the plugs are getting wet with it and it back fired twice (which scared the crap out of me) So I checked the timeing and its on TDC, and the cap and rotors, wires, plugs, and coil is all brand new. So does anyone has any idea what it could be? :confused:

[Mudderoy]

Clean the Throttle body and the Idle Air Controller and its housing.

CPS testing is below -


CPS Testing


Crankshaft Position Sensor Connector


http://xjtalk.com/images/special/cpsplug.jpg


TESTING PROCEDURE 1991 – 2001 4.0L H.O. engines

1. Near the rear of intake manifold, disconnect sensor pigtail harness connector from main wiring harness.
2. Place an ohmmeter across terminals B and C (SEE Image). Ohmmeter should be set to 1K-to-1OK scale for this test.
3. The meter reading should be open (infinite resistance). Replace sensor if a low resistance is indicated.

TESTING PROCECURE for 1987 – 1990 4.0 L engines

Test # 1

Get a volt/ohm meter and set it to read 0 - 500 ohms. Unplug the CPS and measure across the CPS connector's A & B leads. Your meter should show a CPS resistance of between 125 - 275 ohms. If the CPS is out of that range by much, replace it.


Test # 2

You'll need a helper for this one. Set the volt/ohm meter to read 0 - 5 AC volts or the closest AC Volts scale your meter has to this range. Measure across the CPS leads for voltage generated as your helper cranks the engine. (The engine can't fire up without the CPS connected but watch for moving parts just the same!) The meter should show .5 - .8 VAC when cranking. (That's between 1/2 and 1 volt AC.) If it's below .5vac, replace it.

[rguignard]

well we have been talking about this on chat and the 91 and 95 are not the same the ohms are diffrent hope this helps :thumbsup:

[xj4life2]

Check the distributor, could have a cam shaft pos sensor out (its inside) since your a 91 your a renex system try this link for sensor testing
http://www.lunghd.com/Tech_Articles/Engine/Basic_Sensors_Diagnostics.htm

[reddragon72]

I have a 94 and mine died on me. I eventually had to replace the CPS, CSPS(cam shaft position sensor AKA distributor pickup sensor) and the ignition coil. that was a very stressful day and a lot of work for the CSPS.

if your getting fuel then your good there so the CPS is working, so now check your spark with a timing gun or tried and true screwdriver test, I suggest the timing gun can it's safer and you can check your timing. But it sounds like you might have lost your spark which could me the CSPS(pickup coil) or the ignition coil.

[4.3LXJ]

If you have wet plugs, they won't fire. Take them out and dry them in an oven on 220* for a little while. Then install 5 and leave one out and grounded and crank to see if it sparks. If it does, it should start.

[Punisher]

Ok guys thanks for the help so I'm going to have it towed to my house monday and try this out... I'll get back to you as soon as I try this test..

[Punisher]

Ok I put a new 1991 crankshaft position sensor in and it wants to start but i put a little ges in the carb and its tryin to start but then it just turns over... any ideas?

[Mudderoy]

Ok I put a new 1991 crankshaft position sensor in and it wants to start but i put a little ges in the carb and its tryin to start but then it just turns over... any ideas?

Damn that sucks! I can't remember, did you measure the voltage going to the coil?

[Punisher]

well no but im getting spark but i notice i took all the plugs out anda few are dry and a few were wet with gas... this is driving me crazy :smiley-scared002:

[Punisher]

i took off the cap and rotors and they seem to be ok they are not even a year old and same as the wires...

[Punisher]

it feels like its fireing on a few cylinders.. what could cause that?

[Mudderoy]

I'm just grasping at straws here. I'm wondering if you have a computer problem. I'm also wonder if the injectors are all spraying fuel. Have you reset the computer? I mean if it's bad resetting probably won't help.

[Punisher]

yeah i took the battery cables off + and - and waited for a while so the computer should have gotten the new CPS set.. I'm just hopeing its not the onboard computer... i dont have the money to replace that...

[Mudderoy]

yeah i took the battery cables off + and - and waited for a while so the computer should have gotten the new CPS set.. I'm just hopeing its not the onboard computer... i dont have the money to replace that...

I'm hoping someone will jump in here with more ideas. Wait someone asked you about the grounds, right? I remember a member had a problem with it running but as soon as you gave it gas it would die. He had a broken ground running from the block to the firewall.

How much is a computer from the junk yard? I mean it could be bad as well but I doubt it would have exactly the same symptoms. If it was cheap it might be a good way to tell if you needed to buy a replacement computer or not.

I wonder if it could be something simple like contaminated fuel. That might explain why some spark plugs were wet and others were not. The injectors might be clogged, or spraying fuel and water, or SUGAR!

[4.3LXJ]

If those plugs are wet, they won't fire. Take them all out and get them completely dry. I usually put them in the oven on 220* for 30 min. Don't get them mixed up with the cookies though :D

[Punisher]

Check list:
Full tank of fresh gas
ground wire good
I've dried out spark plugs
new CSP
new Battery conectors
Good battery
good compresstion
fuel pump working (new)
cap and rotor (new)
Wires great shape
All vacum hoses checked
and still no firing up :mad0090:
but I've noticed 3 of the plugs were wet and the others are not... ummmmmm???

[4.3LXJ]

I am assuming you get a spark on a plug if you take one out and crank it?

If so, you are left with fuel issues. Are you sure you have good fuel pressure? Any codes?

[Mudderoy]

I am assuming you get a spark on a plug if you take one out and crank it?

If so, you are left with fuel issues. Are you sure you have good fuel pressure? Any codes?

How hard would it be to run an external fuel source to the rail?

[4.3LXJ]

How hard would it be to run an external fuel source to the rail?

It can be done, but you would need a pump that will maintain the required pressure. So you would need to get a sending unit with the pump and hook up that pump in a can of gas or something.

[Mudderoy]

It can be done, but you would need a pump that will maintain the required pressure. So you would need to get a sending unit with the pump and hook up that pump in a can of gas or something.

It just dawned on me. I had my injectors cleaned a couple of years ago. They disconnected the fuel rail and connected to the cleaner. It ran the engine for about 10 minutes just off of the pressurized container. I wonder how much those things cost. That would be perfect for a test.

[Punisher]

I'm hearing the fuel pump work and getting great fuel pressure...:confused:
I just called a buddy that I just remembered that he has a analizer so he going to be coming tomorrow to get it a engine test will see what happens...

[Mudderoy]

I'm hearing the fuel pump work and getting great fuel pressure...:confused:
I just called a buddy that I just remembered that he has a analizer so he going to be coming tomorrow to get it a engine test will see what happens...

Yeah but I'm thinking something may be wrong with the fuel. Wow problems like this scare the hell out of me.

[Four_X_What]

Check list:
Full tank of fresh gas
ground wire good
I've dried out spark plugs
new CSP
new Battery conectors
Good battery
good compresstion
fuel pump working (new)
cap and rotor (new)
Wires great shape
All vacum hoses checked
and still no firing up :mad0090:
but I've noticed 3 of the plugs were wet and the others are not... ummmmmm???

Are the 3 wet ones in a row? Or just scattered. Cant you pull out a plug and hear if the cylinder drops? My Tahoe did the same thing I got AAA to tow me home. 2days later it cranked and has run fine since...

[Punisher]

1,4,5 are dry 2,3,6 are wet.... wierd

[Mudderoy]

1,4,5 are dry 2,3,6 are wet.... wierd


i have a 98 grand cherokee that did the same thing after replaceing the pcm and many other pricy parts found out the o2 sensor is the ground circuit for the pcm and cluster will not run if the circuit is broken have any questions call napa in denver city texas ask for heath


hi emily,
i had the same problem and it was expensive to learn i could have fixed it my self!! get a new battery. i can not stress the misery i went through last summer. voltage was all messed up, would crank and then do nothing. after jumping it would work until i turned it off. or the engine would sound really horrible. just try a new battery. before taking it anywhere!

I found this :link: (http://www.askamechanic.info/askamech2/component/option,com_fireboard/Itemid,53/id,65/catid,3/func,fb_pdf/)

The guy worked and worked on fixing his no start problem. Finally he sold the Jeep as non-working for $450. The new owner got it started. He replaced the new CPS and re-adjusted the distributor coil position sensor. :smiley-laughing021:

[Punisher]

I found this :link: (http://www.askamechanic.info/askamech2/component/option,com_fireboard/Itemid,53/id,65/catid,3/func,fb_pdf/)

The guy worked and worked on fixing his no start problem. Finally he sold the Jeep as non-working for $450. The new owner got it started. He replaced the new CPS and re-adjusted the distributor coil position sensor. :smiley-laughing021:

whats the PMC again? :stars:

[Mudderoy]

whats the PMC again? :stars:

I thought it was the computer. Let me check...

Powertrain Control Module (PCM)

I think ECM is Engine Control Module, same thing as PCM.

[Punisher]

Ok I thought thats what you mean... im wondering if its the pick up in the distributor? but that should not make it spark at all if its that..? im getting some spark on some of the plugs.

[Mudderoy]

Ok I thought thats what you mean... im wondering if its the pick up in the distributor? but that should not make it spark at all if its that..? im getting some spark on some of the plugs.

No popping like a backfire that might indicate a timing issue?

I wonder what is on the flywheel that the CPS reads. I wonder if that could come off.

[Punisher]

No popping like a backfire that might indicate a timing issue?

I wonder what is on the flywheel that the CPS reads. I wonder if that could come off.

Ya know i did get back fire twice and i did take the valve cover off and set it up to TDC and all timing looks great..

On the flywheel are magnetic fields on it but they dont come off.. thats what the machanic told me.. and what they do is tells the computer when to spray fuel and when to spark...

[Punisher]

I'm going to discribe what its doing...
I turn the key to start it up with out puching the pedel
engine turns over for a few sec. and then it trying to kick in
like its not getting furl but i know it is (ive checked it)
as its trying to start it sounds like its only firein' off a few cylinders
as soon as I push the pedel down a little it goes back to turning over
without firing as soon as i let the pedel go a few sec. later it tries
to kick in again and so for...

[4.3LXJ]

I am going to suggest something basic here. Take the wet plugs out, dry them out and crank it and make sure they spark. If not, work on that. You might have distributor problems. Take the cap off and spray it out with WD40 to clean it. You can put it back wet (old mudders trick). If it still will not fire all plugs, check into the cam position sensor on the distributor plate. They can do some weird things sometimes.

[Punisher]

I am going to suggest something basic here. Take the wet plugs out, dry them out and crank it and make sure they spark. If not, work on that. You might have distributor problems. Take the cap off and spray it out with WD40 to clean it. You can put it back wet (old mudders trick). If it still will not fire all plugs, check into the cam position sensor on the distributor plate. They can do some weird things sometimes.

Ok i got spark on 1,5,6 not on 2,3,4 but i put the 2,3,4 plugs on the 1,5,6 wire and they sparked so its not the plugs gotta be sumin else.. im about to just take my 9 and shoot it up :D
and the CPS are on 2000 models and up... i have a '91 unless your talking about the pickup.. thats new

[Mudderoy]

Ok i got spark on 1,5,6 not on 2,3,4 but i put the 2,3,4 plugs on the 1,5,6 wire and they sparked so its not the plugs gotta be sumin else.. im about to just take my 9 and shoot it up :D
and the CPS are on 2000 models and up... i have a '91 unless your talking about the pickup.. thats new

Distributor Pick up Coil is on all models, I thought. I have one in the base of my distributor of my 1998. The 1999(?) through 2001 are sitting on top of a stalk that goes where the distributor used to be.

http://xjtalk.com/images/special/1998jeepdistributor.jpg
This is a picture with the distributor pick up coil removed. I was checking the alignment of this hole with the engine set for TDC.

[4.3LXJ]

Ok i got spark on 1,5,6 not on 2,3,4 but i put the 2,3,4 plugs on the 1,5,6 wire and they sparked so its not the plugs gotta be sumin else.. im about to just take my 9 and shoot it up :D
and the CPS are on 2000 models and up... i have a '91 unless your talking about the pickup.. thats new

Now put the 156 wires on the 234 position on the distributor cap and crank to see if you get spark

[Punisher]

Distributor Pick up Coil is on all models, I thought. I have one in the base of my distributor of my 1998. The 1999(?) through 2001 are sitting on top of a stalk that goes where the distributor used to be.

http://xjtalk.com/images/special/1998jeepdistributor.jpg
This is a picture with the distributor pick up coil removed. I was checking the alignment of this hole with the engine set for TDC.

Im going to have to check that... its down pouring now (florida for ya) Ill look as soon as it stop rainin'

[Punisher]

http://i860.photobucket.com/albums/ab165/punisher1_972/DSCF1267.jpg

This is what I have mudderoy
See if you see sumin wrong?:confused:

[Mudderoy]

http://i860.photobucket.com/albums/ab165/punisher1_972/DSCF1267.jpg

This is what I have mudderoy
See if you see sumin wrong?:confused:

Well if you have the engine at TDC the pulse ring isn't in the right place. So the signal to the ECM is wrong an it will be firing incorrectly. I doubt this is your WHOLE problem but it will help the overall getting it running.

Once you are CERTAIN the engine is TDC #1 cylinder you'll need to remove the distributor and turn the oil pump slightly and re-stab the distributor until that hole lines up perfectly. Like mine is in my picture.

Oh and my really dumb statement, but I like to be sure of these things. You removed the pulse ring sensor to take this picture, right? I mean no sensor, no run.

[4.3LXJ]

Ok i got spark on 1,5,6 not on 2,3,4 but i put the 2,3,4 plugs on the 1,5,6 wire and they sparked so its not the plugs gotta be sumin else.. im about to just take my 9 and shoot it up :D
and the CPS are on 2000 models and up... i have a '91 unless your talking about the pickup.. thats new

Have you checked the cap and rotor yet. A small hairline crack will affect the spark output. Also, dust. You might just need a new cap and rotor. It doesn't take much.

[Mudderoy]

Have you checked the cap and rotor yet. A small hairline crack will affect the spark output. Also, dust. You might just need a new cap and rotor. It doesn't take much.

I don't like all that oil in there either.

[Punisher]

ok i got it at TDC and its lined up like you said mudderoy so thats fine...
and 4.3XJ yeah the rotor and caps are in great shape its like new
but im thinking the distributor is a 1998 and so is the motor but all the rest of the stuff
like the intake and starter and ect. are all 1991 off my old motor its just the block, head, and distributor is the only thing 1998 but it ran good before but now that i replaced the CPS will its be effected by the 1998 distributor?

[Mudderoy]

ok i got it at TDC and its lined up like you said mudderoy so thats fine...
and 4.3XJ yeah the rotor and caps are in great shape its like new
but im thinking the distributor is a 1998 and so is the motor but all the rest of the stuff
like the intake and starter and ect. are all 1991 off my old motor its just the block, head, and distributor is the only thing 1998 but it ran good before but now that i replaced the CPS will its be effected by the 1998 distributor?

I think you have already said, but the ECM is for what year?

[Punisher]

I think you have already said, but the ECM is for what year?

ECM is a 1991

[Mudderoy]

ECM is a 1991

Well it worked before. I really don't know but that surprises me that it works.

[Punisher]

:sad0147:


I'm just about to :pee: on this!

[Mudderoy]

:sad0147:


I'm just about to :pee: on this!

What happened with your friend and the analyzer?

[Punisher]

What happened with your friend and the analyzer?

he got tranny problems and wont make it till the weekend, he lives 45 mins from me :headshake:
Seem im not the only one with car problems :boohoo:

[Punisher]

Well my friend wasnt able to make it so anyways back to square one...
I've replace the whole distributor and cap and rotor and still nutin
but i did the on off key thing and im getting a code 12 and 55
and my book says 12 is "Battery voltage to PMC disconnected within last 50 key-on cycles" what deos that mean? and 55 is " end of code output "

[jeepin_idaho]

OK I'm bringing this one back from the dead... @Punisher, Did the problem ever get sorted or did you just scrap the Jeep?

Dan
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http://the4x4podcast.com