RegularGuy

First off I would like to say that I didn't really want to ask for help, but I've been kicking this can around for what feels like long enough. Seem there are a few other threads up right now about starting issues but I don't want to hijack someone else's thread when the problems aren't exactly the same.

There has been for quite some time an issue where if I started the thing from cold, and then shut it off before its fully warmed up, it wouldn't want to start. Not even crank. Changing gear, etc (NSS thing) even beating on the starter wouldn't always work. Almost like random chance of turning the key, or just letting it sit for about half an hour, it would start right up. After it warms up fully, then you can shut it down and restart as many times as you want.

Lately it seems that it doesn't like the wet or the cold. Specifically both. Twice now it has just cranked and not really turned over (or if it does, it might putter for 3 or 4 revolutions and then just die). Both these times it has been cool (under 40F) and wet. First time it did this (Last Monday when I thought i was going to go to work) I wore the battery down, but after charging it back up i was able to get it going when I held my foot to the floor and turned the key. This time that hasn't worked either. A related issue was that I had driven through some water a few weeks back (not a lot, just a glorified puddle) and then it puttered to a stop. Cranked and cranked but wouldn't really turn over. eventually it must have dried out and then came on, then drove just fine.

>Earlier this year I changed the Crank sensor, as it had failed. It would run like **** and die about halfway to work, and then eventually it just wouldn't turn over no matter what I did. it threw the code for the crank sensor, and when I pulled it off the harness was definitely bad. However I had to replace it with a BWD sensor because a Mopar one was unavailable (at least it was made in Mexico, not China). I could be wrong but I dont feel that it is the new CPS going bad.
>I replaced the Starter maybe 8 months ago.
>The last time this happened I swapped around the ASD, Fuel Pump, etc relays, No change or improvement so I don't believe any of those are the hangup.
>last time I cleaned the grounding of the fender ground, and cleaned the battery terminals as well as cleaned and re-seated the two positive leads in the terminal clamp
>I'm not clairvoyant, but i think the ignition switch is working. The fans, Radio, etc all cut out when it turns to "Start", but other than that, I couldn't tell you. I do know that it appears to have been replaced in the past, as the Ignition key is different from the other locks, and there is no plastic "guard" that they key fits into (I'm assuming anyway that the '97-'98 had the same style ignition as the Pre-'97 ones, as my key is the same as my '96's was. {I guess I assumed in '99 they switched to the style the WJ has, with the WJ-styled round key})

I can't really check for spark because I can't be in two places at once, but I know it gets gas. I can hear the pump prime and can smell gas if I try cranking it a few times after I floor it. I'm thinking maybe the cap/rotor/wires are crap? Drawing moisture or something?
I have not replaced this battery since I picked this XJ up a few years back. It might not be related to the "Sometimes wont re-crank when you shut it off" problem, but maybe the battery is worn out and doesn't have enough CCA to actually turn the motor over when its like this out anymore?

Sorry if this is a bit ramble-y, I've helped myself to some libations and don't really have anyone else to bounce my thoughts off of. I'm not even sure all these problems are strictly related or not, just some observations when it comes too ol' XJ starting up.

awg

could need a cap/rotor/leads change

check the dizzy connector and wiring integrity

coils can go bad

cam sensors can go bad

thats the order I would go,

make sure your battery is ok, more than a few years might warrant a load test

Roler

That's a lot of text..

Well, it's kinda important to diagnose a spark or no spark. You will need to do some diagnostics.

What you can do, is buy an inline spark tester.
​​Install it. Then take out the starter relay (located in the PDC in the engine bay), make sure your transmission is in Park, turn the key to On/Run (not Start), and jumper terminal socket 30 and 87. Watch the spark tester.

Let me know what happens

RegularGuy

It did start today relatively painlessly. I took the battery off the tender, hooked it up, and after trying it a couple times, then putting my foot to the floor and trying again it fired up. maybe 5 attempts altogether.
I definitely want to get this battery tested. It might not be the cause of all of my issues, but I don't see it being helpful.

Roler, as for the wall of text, yeah I can understand that. What I do know is that I have poured over a lot of old forum posts on different forums over the past year or so looking at pointers for things here and there, so I figure if I am as descriptive as possible it can help others get a grasp of what is going on both in the present and the future if they compare their problems to my own.

Hopefully (if it acts up again) i will have a helper nearby who can assist me in checking for spark.

Roler

That's why I gave you that method: you could do it by yourself

Santiago Rebollo

Good day every one. I’m new to the Jeep community and am in need of some help. I have a 1991 XJ that I picked up fairly cheap. When I bought it the young man stated that it would start but immediately shut off which made me think something wrong with the ignition but when the jeep arrived at my house I learned that it had a broken steering column. I began by replacing the steering column and key and then could get the vehicle to crank but it would backfire. And then proceeded to check the timing and put the Jeep in timing (4.0). The vehicle would just crank and not start. Make sure all the grounds we’re taking off and cleaned and still no start. I then verified that I had spark and as it appeared week I replaced the ignition coil, the crank position sensor, spark plugs spark plug wires, rotor, distributor, cap just to be safe. When replacing the CPS I did learn that he had recently been replaced along with the throttle position sensor. Still the jeep will not start only cranks. With the ignition is turned on you can hear the fuel pump and with ignition on we’re getting 45 psi at the rail and went cranking 55 psi. We’ve tried starter fluid, we also checked the neutral safety switch and still nothing. I took the computer in to be tested I was advised that the computer is good as well as previous repairs done to it have held up well. I was told to test pin six at the computer for 5 V and pin seven for 8 V and they both checked out, was also asked to check pin 24 And I get anywhere between 7 to 8 V while cranking. I was told the pen 19 should have the same amount of voltage as the battery one not cranking however I’m getting .24 V there. I will be tracing this wire to see if there’s damage however wanted to see if there’s anything else anyone can think of that may help us get this jeep to start. Any help would be greatly appreciated, thank you all in advance!