Need help on my 95 zj 4.0

My 95 zj 4.0 suddenly wont start, ive had to jump a 6 month old battery and then jump a week old battery, also idk if it has anything to do with my problem but my tachometer and speedometer tweak wheb i drive it, but ive replaced my distributor, cap, rotor, ignition coil, starter, crank sensor, a week old battery, fairly new fuel pump, fairly new alternator, i test my MAP sensor and it tested good, i have spark all the way through out the spark plug wires, fuel is goin where its suppose to go and have no air leaks, timing is dead on cuz we put it top dead center when i lined it up, timing didnt jump that i know of, but all it does is turn over but doesnt start, it has great compression, ive checked or replaced everything i can think of but it will not start, im confused and stumped, any info will help, thank you in advance

If you have spark and fuel (and it turns over but not runs) then maybe the o2 sensors. Those can keep a jeep from running.


Dunno about the battery drain.



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But wouldnt a o2 sensor throw a code? Cuz i have no codes showing at all

Most anything wrong should throw a code but they don't for some reason, even new cars have gremlins that don't trip a code.

The o2 sensor for the jeep can cause no start, dozen of threads where the no start with no code (sadly not common to these jeeps) was something simple, like o2 sensors or even out of the box bad replacement parts.
I'd just unplug them and see what it does, if they are bad they could be making it too rich to start.
If they are bad there is a certain brand to look for because jeep don't like one of the common brands, Bosch I think but could be wrong.

Another off wall culprit can be the Cam position sensor in the distributor.
Bad grounds too.

If nothing else proves to be wrong I would think about a cheap junk yard computer swap. I might even try that anyway if you can match the number cheap enough.

If you've got spark, fuel and the timing is correct, IMO then it's something messing the timing up or fuel. Assuming all the replacement parts are good. Many of the guys here would (based on experience ) say start at the beginning and verify it all again. Might seem harsh when your the guy who's spent all the time trouble shooting what you have already.


The battery drain is a weird problem, and the gauge cluster going wonky. Some of these readings go through the computer on the xj, could also be a loose cluster plug.



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Just did some searching some zj guys seem to lean towards a pcm(computer error) apparently it's not uncommon

http://www.jeepforum.com/forum/f13/...art-1123340/#/topics/1123340?page=1&_k=a7sasd

Dose your zj have a factory alarm?


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It does have a factory alarm and i bypassed it, ive heard the IAC can keep it fron starting, how would i beable to test that? I tapped on it with wrench like i was told and it did nothing, is there a way to test it with a mutlimeter??

when its running how does it run is it smooth or jerky

Try starting with the throttle wide open, if it's something like TPS or IAC it should start or stumble ,
Not sure the IAC would keep it from starting. Not hard to replace if you need to. I'd think you'd have noticed something when it was running.

TPS test way down the page
http://www.jeepforum.com/forum/f11/bad-tps-symptoms-937669/#/topics/937669?page=1&_k=8tgte2

IAC problems
http://www.naxja.org/forum/showthread.php?t=90809





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It cranks over smooth and i tried the throttle pressed down all the way, still just cranks over

Did it run smooth before it quit starting?

Other thing is the sensor get voltage from the PCM/ computer. Does it do any of the things the ZJ guys describe like waiting for CEL ?


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It ran smooth before this happened, no engine code or anything happening, just turns over and over until it drains the juice out of the battery which is only a week old

Did the cel come on as part of start up before? Some zj folks describe the cel coming on as part of normal start up .

You should have at least one code for the battery being disconnected.


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Your speedo and tachometer jumping around are most likely not related to the problem, but I just ran into this problem myself recently and fixed it. (After starting a thread on it. I'll update that one appropriately.) Long story short, check and clean your ground wires and terminals. It seems the ZJ is a little different, but the ground wire(s) I suspect are faulty on yours are most likely on the fender opposite the battery. It looks like it's a black and orange wire that splices into a black wire.

I checked all my ground wires, the only one that was some what loose was on the battery, but i tightened it up yestarday and still have the no start problem, but can this abs thing thats on the drivers side in between the fender and air filter box keep it from starting? Cuz i just remembered that the night before, my abs light was on, which i dont think it ccn keep it from running, but its worth a shot