4.0 stalled on hard right turn, cranks but doesn't fire, no spark. Help fix it!

[johnsoninc86]

About three weeks ago, the jeep would die on hard right hand turns, but would restart itself, and keep going on its merry way. It seemed to only happen with less than a 1/4 tank of gas in it. Well, it did it again this week, except this time it didn't restart itself. It cranks and cranks, but doesn't start. I went ahead and replaced the fuel pump because of the weird symptoms of turning right and less than a 1/4 tank, but that didn't fix the problem. So, I checked the spark, and it has no spark at the spark plugs. I did not check the spark at the coil though. I figured it was the usual CPS, but after replacing that, it still just cranks and cranks, but does not fire. I'm running out of options here, and I don't want to just throw parts at it.

The only other things that I can think of that it might be would be an ignition coil, ECM, or a short or something in the wiring. The problem seemed to only happen on hard right hand turns, with less than a 1/4 tank of gas, but it only happened three times, and the third time it did not start back up. The check engine light came on for second when it died, but it turned back off after trying to restart it, and I couldn't get any codes from it. I noticed on attempting to start it, all the lights come on on the guage cluster, except the check engine light, and none of the guages register anything, but the odometer lights up just fine. My gas reads nothing, voltage nothing, and engine temp didn't read anything even when the engine was still hot after it stalled.

Its a '98 XJ, 4.0L, AW4, and 238,000 miles on it. Help me out guys, I'm stumped. Thanks in advance.

[bullardsbarbarian]

I had something similar in my 96. Check for a ground lug on the side of the block above the oil filter. It will have a few wires coming out of the wire harness attached to it. If any are loose, they could be causing your problem. Also check the fuses in your PDC. IIRC, the 30 amp mini fuse feeds power to your injectors, o2 sensors, ignition and some other stuff.

[Cherokeefever]

It sounds to me like it`s the crank position sensor which is located on the top driverside of the bell housing and plugs in by the firewall side of the throttle body.

[the_weirdo]

Did you replace the fuel filter that is in the tank when you replaced the pump? I had the same problems with my '98. Go to ebay and find the guy that is selling the fuel filter and the pump for around $75. When you go around corners the gas sloshes away from the pump and you run out of fuel. The filter is dirty and doesn't let the canister fill up with fuel as fast as a clean filter.

Here's a write-up from a guy with the same problem: http://www.jeepforum.com/forum/f11/f...97s-up-138580/

Edit:
How did you verify that you are not getting spark?

[johnsoninc86]

I replaced the fuel pump, and both of the fuel filters in the tank. I checked spark by taking a plug out and holding it against the block while cranking. I checked the 2nd cylinder when counting from the front to back, just because it was the easiest to get to.
I already replaced the Crankshaft position sensor, the one on the bellhousing of the tranny. That was what came to my mind first after not getting spark.

I've been researching all night, and its starting to look more and more like a bad ECM. I've found several threads over on JF and guys have the same EXACT symptoms I do, except for the dying on right hand turns deal.

Exact situation I'm having--> http://www.jeepforum.com/forum/f11/9...-spark-836664/

I have symptoms that are pointing to either a bad Crankshaft Position Sensor, or a bad ECM, now I just have to figure out which one it is. A lot of people have said it's possible to get a bad CPS right from the store, so its either that, or the computer.

[XJosh95]

I would be checking wiring. You're already throwing parts at it without correct diag which will cost you so much more in the long run as you have probably already seen. Wiring can do some funny things. Turning to the right may have got your engine/wiring/whatever to shift at to just the right point to cause loss of continuity. After that happened over and over, you may have a broken wire or loose connecter, etc. Looking at your camshaft position sensor may help too. Check out the cap and rotor (free to inspect) for corrosion or loose connections, etc. Trace wires till you you can't see straight. It's a headache, but it'll save you $$.

[bullardsbarbarian]

You might have a rub through on the wiring for the o2 sensor. I had this happen a couple of weeks ago with very similar symptoms. Check bellow the manifold at the front of the engine. There may be a rub through in the wire loom against the block. The culprit should be the green wire with orange stripe. It powers your ignition, fuel injectors, o2 sensor and sends power to your ECM. It is the ASD circuit. Also try swapping relays and definitely replace fuses. They are cheap and I've often seen fuses that looked good that weren't letting power through.

[johnsoninc86]

Well, I ended up figuring it out. When it first stalled, I went through all the fuses, and didn't see any that were obviously burnt out. After I replaced the ECU with a known good one and it still didn't fix the problem, I went back to the basics and started rechecking the fuses. This time I checked them with a test light, and low and behold, fuse #11 (Ignition, daytime running lights) was burnt out, but not right in the middle where it was supposed to be burnt, it was burn way down on the fuse where it was barely visible, so I looked right over it the first time. I replaced the fuse, and, bang, the jeep fired right up. It ran for about 5 minutes, then popped the fuse again, so we started looking around for shorts. I didn't find anything obvious, so I threw another fuse in it and as soon as the ignition went to the "ON" postion, it popped the fuse immediately. So I dug into the iginition column, and still didn't really find any wires that were rubbed bare, but I found a couple that were scuffed a little bit. I went ahead and wrapped them good with electrical tape, and unplugged and replugged everything in there to ensure a good connection. I alson check every wire that I could under the hood, and swapped some of the relays around under the hood in the PDC. According to my Haynes book, that fuse runs through the fuel pump relay in the PDC. Well, after doing all this, I put in a new fuse, and everything runs perfect. I've driven it on a 45 min drive, and then a 4 hr. drive, and it never skipped a beat.

I feel like I didn't really fix the problem though, because I never really found a bare wire or anything that would lead to blowing that fuse that many times. Does anyone know what else fuse #11 runs through, or where it is routed?