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Xj intermittenly dies when driving

W

Winniethepooh

NAXJA Forum User
Location
Wenatchee, WA
Long story short. My 93 XJ has an intermittent stalling issue. It died on me while driving home yesterday. It was at operating temp. This morning it died on the way home from the gym this time it was cold. I hit the brakes to stop for the sign and it stalled. I've done a complete tune up, replaced the cps with an Eichlen model from napa (I know) so this morning I checked and cleaned the PCM plugs. I also checked the spark plugs and cleaned them a bit. Looks like they have high speed glazing on them. Anyways I test drove it and this time it didn't die and i got it to operating temp. Wtf? Any help would be greatly appreciated. Cheers.
 
If it stalls when you stop, the first thing I check is my IAC. I usually spray a few shots of penetrating oil down the IAC opening (inlet) with the motor running, while working the throttle a little (between idle and say 2000 RPM) to flush any grit or sludge that has lodged in there.

This can also be a sign of charging or battery issues. The IAC seems to be voltage sensitive and may act up before you notice any real charging system issues.

About a fifty fifty split for me when I have IAC issues, between dirt in the IAC and charging system issues.

The only air your motor gets when your foot is off the throttle is thorugh the IAC, if it sticks shut, no air and the motor dies.

I don't think the 93 has an EGR valve. If it does, this will also stall you at a stop or at idle if it sticks open.
 
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Few things come to mind....

As 8mud said, IAC is worth checking out, and cleaning it isn't too big a hassle (it's two screws and an electrical connector)

The IAT which is a screw in part on the intake manifold often gets crudded up, the typical symptoms of this are low idle and frequent stalling, pull it out with a (17 or 19mm OE wrench) and clean it, I usually use break cleaner but other people recommend different electrical cleaners, it usually gets gunked up from blow by.

Also, since it's probably nice and cold on your side of the hill, check your air filter and make sure it's clean. Battery terminals are also a frequent cause of consternation, pull them apart and clean it with a brush especially if you have any evidence of corrosion (white salt)
 
Well I already cleaned the iac. Today I sprayed a little pb down the inlet near it and cleaned the iat and it seems to have fixed it....for now lol. Thanks for the help so far...
 
You may want to get your battery load tested. do some battery maintenance like cleaning the poles, checking your grounds and maybe do some periodic voltage tests on your charging system. If it just wasn't dirt, you may have an underlying charging system issue that is likely to get worse quick as winter hits.

Twice my IAC started acting up, once my alternator died shortly after and the next time (a year later) my battery failed. The IAC started acting up before I ever noticed the charging issues.
 
Ok since my last post I had to park my jeep for a week because it kept acting up. I replaced the battery and the cps with a mopar unit. All was fine for a few days and it started stalling out on me again. It doesn't matter when it hot or cold. I have refreshened the grounds, replaced cap, rotor, plugs, wires, fuel filter, cps, and battery. I got it to stall in my parking spot and this time she threw a code 11 at me. During my no start I checked the asd relay and no help there. I unplugged the cps and plugged it back in and she started. When running I can sometimes grab the cps plug and it will die. But will always restart. Any more help would be appreciated. Cheers
 
The IAT (Idle Air Temperature) is a brass plug on your intake manifold, because it sits in the air stream in inevitably gets covered in all kinds of crap that either recycles from the CCV/PCV or that isn't trapped by your air filter. If you pull it out, and then clean it off with brake cleaner (not the electrical connector, but the business end, it kinda looks like a bird cage) your problem should go away.

I had a very similar issue with my '90 renix a few months ago, cleaned the IAT with some brake cleaner and goodbye!

The IAT is often responsible for low idles, and frequent dying. Another thing to check just for S&G's is your fuel pressure regulator (I also had this problem), get the engine running for about 30 seconds (if it dies before that, it's fine), shut it down, and then pull the vacuum tube that's on the end of the fuel rail. If there's any gas there that's an additional issue.

Also, if you damage the IAT, you will get a permanent high-idle.
 
BulletMaker said:
The IAT (Idle Air Temperature) is a brass plug on your intake manifold, because it sits in the air stream in inevitably gets covered in all kinds of crap that either recycles from the CCV/PCV or that isn't trapped by your air filter. If you pull it out, and then clean it off with brake cleaner (not the electrical connector, but the business end, it kinda looks like a bird cage) your problem should go away.

I had a very similar issue with my '90 renix a few months ago, cleaned the IAT with some brake cleaner and goodbye!

The IAT is often responsible for low idles, and frequent dying. Another thing to check just for S&G's is your fuel pressure regulator (I also had this problem), get the engine running for about 30 seconds (if it dies before that, it's fine), shut it down, and then pull the vacuum tube that's on the end of the fuel rail. If there's any gas there that's an additional issue.

Also, if you damage the IAT, you will get a permanent high-idle.
Click to expand...

If got to mention I did change out the iat with a new unit. I'm thinking now it could be the pick up coil in the dizzy. I took it to a shop near my work and they said 90% chance it was the cps if not it was the coil or the pick up.
 
Interesting, however apparently I didn't read the whole thread and posted the same advice (twice) man, I hate it when I derp out like that.

Anyways, if there's mention of something related to the spark/CPS/etc check the wiring harness on the CPS first, if it looks all folded over and nasty you might want to cut it shorter and install new connectors. Changing the CPS is a PITA, especially with my big hands, and I've done it twice on several jeeps only to find out it was the wiring harness above the CPS connector. Something I find really annoying.

One way you can test for this... if it dies periodically and doesn't start right back up (this usually is a problem when hot) pop the hood and shake the CPS wire, if it fires back up after a few tries it's probably the engine wiring harness not the CPS.

I really hate CPS issues.
 
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