help!!!! 96 Xj wont start

[kirkandsylvia]

Ok...here is the short of it....my daughters 96 xj shut off while she was driving. Her battery died a couple of days earlier, so I replace it. 2 days later it died while driving it. I figured the alternator stopped charging so i replaced it. Now....it turns over but doesn't fire off. The long of it is this....I have replaced the crank angle sensor....the coil....the spark plugs and wires....the rotor....the electrical device under the dust cover in the distributor....and cap...and still no start. I'm not positive.....but I think I have covered every electrical piece that would cause it not start. The only thing left is the computer. Is there any other cheap part that I'm missing that would cause it not to start? Getting very discouraged.

[inVERt'D]

I have heard of ECMs (computers) dying due to the battery getting too low then using the alternator to charge it. I think it's pretty common knowledge that can blow alternator diodes can be blown that way, but the ECM I think not so much.

[Zoobi]

don't rule out a fuel problem. open the throttle and spray some starting fluid or wd40 into it, then try to start it. if it try's to start, look towards a fuel issue. It could be as simple as being out of fuel with a bad gauge, a plugged fuel filter or pump. don't rule out a blown fuse either or a bad ignition switch not powering part of your fuse block. grab a test light and make sure your fuse block has power to all the fuses with the key on (exception maybe dash light fuse if equipped)

[6spdYJ]

Just had the same problem, died on the run - cranks and won't fire. Look at the 30A fuse in the power distributon box. It powers the fuel pump and auto shutdown relay.

[kirkandsylvia]

I have checked all fuses under the hood and under dash...i have tried starter fluid to indicate a bad fuel pump...and I have checked voltage on all terminations at the back of ignition switch. When I replaced the alternator, I noticed on the back of it a wire (module) connection. It comes from the wiring harness and feeds into a black plastic box looking thing. It has 2 terminations coming out of the box going to the what I think is the exciter field connection of the alternator. Out of the same black box is 2 more wires that terminate to the casting of the alternator...assuming that is 2 grounding points. One of those castings points was broke off. Thinking electrically...if I lost a grounding point of the exciter field...Im thinking that one of two things happened. Possibly overvoltage accross the entire electrical system which the computer would be a weak link and it fried it....or because the battery wasnt getting a charge while my daughter was driving that it ran the battery so low that it glitched or fried the computer on a undervoltage. Any thoughts on that theory?

[2blk2drs]

http://www.naxja.org/forum/index.php

[kirkandsylvia]

Went to that site.....but didnt see anything that pointed me in the right direction ...could be just me and my lack of patience of.looking thru a bunch of threads. But thanks anyways. I ordered a computer that should be here begining of the week. I'm Hoping this will fix it. Wife is getting tired of taking daughter to and from work

[kirkandsylvia]

Well.....put a new.computer.in the jeep today......and much to my surprise....it still.doesn't start. I think my next and final step is to rent a backhoe .....and go out to a nice quiet area in the middle of no where.....dig a really big hole and put the jeep out of missery. That will most definitely make me feel better!

[6spdYJ]

Back to the basics... Have you verified spark and/or fuel?
Very unlikely that low voltage would cause it. Yes, it will cause higher current to items like lamps that require lots of heat but for IC's and the like that have a fairly stable current draw, once the voltage drops below the operating threshold, they just shut off until the voltage comes back up.

[kirkandsylvia]

The spark I think is the problem....it doesn't have any. I have changed everything I can think of that has to do with spark. As for fuel....I tried starter fluid to see.if that would at least start it......and it didnt. Is there a link between oil pressure and starting.......as in.....does the oil pressure have to be presents for the computer to initiate spark?

[6spdYJ]

I'm not aware of a stock oil pressure shutdown. Try spinning the motor with the distributor cap off to see if the distributor shaft turns.

[xtimmax]

Did you check the CPS? (Crank position sensor)

[kirkandsylvia]

[CENTER][/CENTER]

Did you check the CPS? (Crank position sensor)

Is the crank position sensor the same as the crank angle sensor? I replaced the sensor thats on the top driverside of the bell housing. When my wife went to auto zone they said there is both.....an angle sensor and a position sensor. Is this true?

[dktool]

Well.....put a new.computer.in the jeep today......and much to my surprise....it still.doesn't start. I think my next and final step is to rent a backhoe .....and go out to a nice quiet area in the middle of no where.....dig a really big hole and put the jeep out of missery. That will most definitely make me feel better!

I may be able to help, I have a BIG back yard and my neighbor has tractor I can borrow. :hide:

[kirkandsylvia]

I may be able to help, I have a BIG back yard and my neighbor has tractor I can borrow. :hide:

If it wasn't for the 2 1/2 acres I'm on....and 7 kids to dig hole for me....I'd take you up on that offer. I would really like to solve the mystery of the no starting issue...maybe when I get done collecting all the tools and old parts that ive thrown all over the place. But for now....the jeep is in a serious time out for being bad....and to really punish it....I'm working on my new 78 cj project....right next to it. I will show it who is the boss