Baffled???

[TrrboJeep]

Hello all,
I am at my wits end with the Jeep... Honestly considering parting it out piece by piece on ebay! I have never ran up against a problem that I could not sort out myself on a vehicle, but I am just about ready to say uncle on this one! It has not been running right for several months, but up until a week ago at least it ran. Now it is dead. The strange thing is I have fuel and I have spark, the 2 ingredients for combustion, but it won't hit a lick!

I have checked or replaced the following components;
spark plugs, plug wires, distributor, rotor, coil, cam sensor, TPS, MAP sensor, set & tripple checked timing, crank sensor, fuel pressure... I'm about out of options & patience. I even spent a day pulling the timing chain cover to make sure the gears haden't jumped a tooth.

I am about ready to make a list of what I could get piece by piece, and if it is equal to or greater than what I want for it, ebay here it comes.

The only thing that comes to mind left to suspect is the computor and they are unavaliable from the dealer, (I called) so I would be left trying to scroung one from a junk yard. I have a couple of things left to try and then I'm going to start the disassembly!

[Lee'sdaytona]

ok a few things. You may remember, I'm the one who's roommate bought your book on turbocharging a jeep. He is a member of "jeep forums" but I don't know the actual site. is there an ASD relay? That might explain the no start, but I don't think It has anything to do with running rough. Could your cat. converter be plugged? I mean, you probably have it running on the rich side with the turbo and all, so maybe it plugged up? And my last suggestion: Since its almost impossible to find wranglers in the yards, why not ask on jeep forum, this forum, and even check ebay for computers?
Good luck, and DON"T GIVE UP! you have a unique jeep, not just another mud- mobile, so maybe take a break and when you get the motivation, go back to working on it.
-Lee

[Murphy]

fuel pump and filter?

[3Bar_Mopar]

Check your cam when the engine is turning over. It may have snapped or even chewed the keyway off and just the gear turns.

[turbovanman²]

Do you have access to a scanner?

[BadAssPerformance]

The strange thing is I have fuel and I have spark, the 2 ingredients for combustion, but it won't hit a lick!

Timing is #3 on the list of requirements.

[TrrboJeep]

Fuel pump and filter are fine, timing is correct, cam is not broken I just checked it out last week when I replaced the timing chain and gears with a Mopar double roller set. I have no CAT on this vehicle. lol I thought about the ASD relay, but if it were shot, I wouldn't get any spark. I have access to a scanner Simon, but I'd have to tow the vehicle to the shop where the scanner is. It is throwing no codes?

After racking my brain yesterday, I now believe it could be my coil. It will create a spark when you have the plug out and grounded to the head, but it isn't that great of a spark. (it doesn't "snap" when it jumps) I think it is getting blown out when cranking under compression. It is less than a year old, but that doesn't mean anything. I have a backup that I will try when I get home tonight. *fingers crossed*

[turbovanman²]

I am suggesting a scanner because you can see the data when cranking it over etc, sometimes, it shows the obvious.

Any chance a factory anti-theft system is kicking in? if you have one that is.

[TrrboJeep]

Any chance a factory anti-theft system is kicking in? if you have one that is.

Nope... It doesn't have one of those. Thankfully its not that high tech.

[TrrboJeep]

I swapped in a different coil last night to no avail.
I will check to make sure I don't have a bad ground on the coil. It was raining last night so I didn't have a chance to do that yet.

[Warren Stramer]

Joel, I remember looking over your awesome jeep a couple times but I don't remember many details but maybe I can help you never the less. Now and then I will get a no start puzzle towed to my shop and I will share a few things that come to mind. First I will assume the basic tests you performed so far (spark, fuel, and timing) are all within specs. SO, first I have some questions......

How did the no start happen to occur? ( shut down hot and not restart next morn.?) ect.
were there ANY warning signs before no start (surging, Hesitation, misfire?)
What fuel type are you using? what is in the tank now?

I have had three customers vehicles inadvertantly get trace amounts of diesel fuel in the fuel tanks causing no start. You will not be able to smell the diesel in the gas when you take a sample, I put a sample from the tank in a shallow pan like a large jar lid and let the gas evaporate. the diesel smell will remain and become obvious as the gas evaporates.

I have also had engines that would not start after a head gasket replacement or after the cyls. were fuel washed ( GM 3800 V6 are notorious for this) We just remove the spark plugs and squirt an oz. of oil in the cyls. and crank it over till the compression raises enough to start.

I have also had a Chrysler 3.5 V6 that would not start, It had everything a engine needs to run but defied logic. Out of frustration I took a hack saw and cut the exaust pipe off behind the Cat and to my amazement DOG FOOD came pouring out!!! Exaust was completely plugged (DAMN MICE)

Is your jeep fuel inj.?

Not saying any of these things apply to your jeep but may be worth a look

Hope this helps. good luck, Warren

[TrrboJeep]

First off let me say thanks to all that have replied with suggestions. I have thought about everyones helpfull hints as to the problem.

I have always felt that whatever this issue was, that it was something simple. Something so basic that I would look like a fool when it finally surfaced. I may have found it last night, & yes I look like quite the fool.

Warren, yes, the Jeep is fuel injected. The Jeep just seemed to start loosing power over several months. It then progressed into a "running so rich" senario that It would barely stay running. Then it would cut out (cough & sputter) above 3,100 rpm (the point at which the factory computer really lengthens the pulse width on the injectors). This finally turned into not running at all. Would crank & crank but not start.

The above conditions progressed over a 4 - 6 month time frame. Which has always led me to suspect an ignition problem. Well, yesterday I pulled the coil wire off and decided to check it for resistance. I am running a set of cheap Autozone wires. I replaced the nice high dollar set of Jacolbs Energy core wires that were on it with these about 1 year ago because I had a miss, and wanted to rule out plug wires. (big mistake) The 1 year old Autozone wire had a resistance of 4,700 ohms! I then went out to the garage and pulled out the Jacolbs coil wire that I had kept (luckily) and checked it. It had a resistance of 136 ohms!

I have also been running an Autozone coil that I had replaced my stock Mopar coil with about 1 year ago as well. I have both coils with me and will go have them both checked today after work. I have a gut feeling the coil is probably as weak as the wires. Either way I will put the good wires back on tonight with the better of the 2 coils and give it a try.

If it turns out to be plug wires what a kick in the crotch!

A week or slowly failing spark would definately explain the above senario and the way it ran up until it quit!

[Frank]

If that is the case... change your oil... fuel down the cylinder walls and into the oil is never a good thing!

[TrrboJeep]

If that is the case... change your oil... fuel down the cylinder walls and into the oil is never a good thing!

+1 Good call...

If this works I will be the happiest fool in Michigan tonight!

[Subliminal]

Just for YOUR information, you might want to read this thread. Different engine, same subject...spark plug wire analysis. Just came up the other day too:

http://www.nloc.net/vbforum/showthread.php?t=128745

[Tony Hanna]

I worked on an Omni awhile ago that had a section of the conductor inside the coil wire burned away. You couldn't tell it externally and it would make a really weak spark. I stumbled onto it pretty quickly out of luck. If not for that, it probably would have been one of those nightmare problems that took forever to track down.

[Subliminal]

That's actually happened to me a few times. Those damned coil wires!

[turbovanman²]

Just for YOUR information, you might want to read this thread. Different engine, same subject...spark plug wire analysis. Just came up the other day too:

http://www.nloc.net/vbforum/showthread.php?t=128745

Nice link but I already knew that,

I prefer Aurora and I'll tell you why. First there made locally which is great for custom stuff but 2nd, they don't skimp. Aurora, MSD and Taylor all use metal spiro core wire, which doesn't break down like carbon core's do-IE OEM, Bosch, NGK etc but they use different size cores, Aurora uses 8.5mm, MSD and Taylor use 4-8mm. I have a Taylor Race set, 10mm and cut apart, its simple reg wire with more insulation added and the core is only 4 mm, so the poor sucker paid double for RACE WIRES and got a puny wire. I have driven vehicles and felt a difference after swapping wires. My old mechanc changed his and didn't tell his wife, she drove the truck and asked what he did to it, it was peppier.

[TrrboJeep]

Well, I had both coils checked yesterday at a reputable local shop and both were good, went home and put the original Mopar coil back on and the good plug wires and............. nothing.
I have a couple of last things to check out and then I'm towing it to a local BP Procare and paying them to find the problem... (for my sanity's sake)

[TrrboJeep]

There were 2 things wrong... 2 simple things!

First, I had the distributor in 180 degrees off. Still not sure when or how I accompolished that? But after correcting that I got it fired up and drove it to Autozone to have them hook their scan tool to it and tell me what they could. The only error message was too high of voltage on the MAP signal, back to the PCM.

So home I went, busted out the zener diodes and problem solved.
Evidently the controler I had on their was dealing with this for me, and when it went south on me the problem arrose.

What an ordeal! I put the +40's back in, and set the boost at 16 psi. all seems to be back to normal.