nocoolusername

ok guys and gals. I am so frustrated I don't know what to try next.

long story ahead hang on.

this jeep is a 93 cherokee with the 4.0 it has 199,000 miles on it. my son drove it out of town this summer and it quit on him. would crank but not fire. I brought it home in a trailer.

I should mention that last winter I put in a new high torque starter, and new spark plugs.

while he was trying to get it started a helpful bystander told him he had a bad starter and proceeded to try to jump start it. obviously this did not help.

anyway I brought it home. I assumed it was probably the crank positioning sensor so before I even looked at it I picked one up at oreillys and swapped it in. it still would crank but not even try to fire. so then I had my Dad come over to help. He isa pretty good mechanic but he is retired and has not done a lot on later computerized engines. he is top notch on carbureted vehicles though.

1. replaced crank position sensor.

ok so we started trouble shooting. the first thing we found when we pulled the distributor cap off was that the insides of the distributor were in pieces. the cam position sensor etc. was broken.

2. replace distributor, cap, and rotor.

so then it still would not start. it would not even fire. so we tested the coil and found that we were getting no spark from the coil.

3. replaced coil.

it still would not start. but at this point we were getting spark from the coil wire.

4. checked fuel pressure at the fuel rail. it was ok.

5. checked compression. it was not great but ok. around 100 on 4 cylinders 90 or so on the other 2.

so at this point we thought it must be timing. we had spark, fuel and compression it must be timing so we pulled the timing cover. I was not about to go to all that work for nothing so before we took it apart I bought a new timing chain and gears. the timing was ok however and the chain was loose but not terrible.

6. replaced timing chain and gears.

at this point I thought maybe that new crank sensor I got was bad out of the box so I swapped the old one back in, but it still did not help. (this was before I learned how to test the sensor.)

7. swapped old cps back in.

8. then I bought a used guaranteed computer and swapped it in and still no luck.

at this point I was very frustrated. and since the engine was a greasy mess and had 200,000 miles on it with low compression I felt I was just polishing a turd. so I decided to pull the engine and tear it down so that at least I was working with a good starting point.

9. engine overhaul.
-bored .030 with new pistons and rings.
-bearings
-comp cams camshaft
-waterpump
-harmonic balancer
-heads with valve job replaced all valves and seals. proper valve springs installed.


in the mean time I bought a third crank sensor at napa and tested all three and the 2 new ones tested the same resistance and the original had zero resistance so I installed the new one from napa with the new engine.

so we bolted the engine in yesterday. i put in a new fuel filter and 4 gallons of fresh gas.

10. fuel filter and gas.

tried to fire it up and it would fire and it even ran briefly. terrible but it ran.

thought maybe we had the distributor in one tooth off even though we installed it when the head and the front cover were off so we pulled the distributor 80 million times and still it won't start.

11. new plug wires.

here is a picture of the rotor with the engine at top dead center. there are 2 marks the one to the right is the center post of the number one cylinder the one to the left is the left edge of the number one post. I tried it one tooth ahead and one tooth behind this position and It still won't start.



I tell you I have tried everything I know how to do. the check engine light has not come on. I have rechecked the firing order 8 billion times. I am at a loss. anybody out there have any ideas at all.?

btw I have the fsm and It hasn't helped unless I missed something in there.

XJamsoil

man seems like alot of work has gone in with no results. Sorry I could not help but hope someone has some info for you.
Only thing I can think of would be 180 off. I'm more than sure that you have checked that.
Pretty sure someone here on the forum could assist with that and get her on the road again.
I'll be watching this thread for sure.

1988cherokee

well for an engine to run you need spark fuel and air your not getting one of them, just because you have fuel pressure does not mean the injectors are firing. I forget which wire you need to put a probe into but one of the wires on the injector you can put a test light on and as you crank it the test light should flash multiple times if not then your injectors arent firing
hope this kinda helps

mcguyver_xj

Ok so you went and replaced timing chain without checking timing on the dist. Thats not a good move and how is your pick up coil thats what turn the dist. Spinning into spark signal for the coil...are you getting spark at each cylinder? And you could also use a noid light on each injector to check pulse make sure there all firing...and you should not have rebuilt the engine your compression was fine most specs for compression are within 10% of each other...

RollingstoneXJ92

I don't know if this will help. i had an issue with mine where it ran terrible and even for a couple days would not start. Could not figure out why. then someone came over to help out and somehow the timing of the distributor was off. We rotated the spark wires clockwise or counterclock wise..i can't quite remember. its been a little while. But sure enough..it worked. Like i said..don't know if it will do you any good..just thought i would share.

cdf43

What about O2 sensors. Mine ran like crap and died right after starting it. O2 sensor fixed that

freegdr

dist deff off by one tooth ,tdc is not the same place as timing gears dots lined up ...sure dad nos tdc compression stroke ,i would set tdc using no1 pistion to make sure dampner not turned giving bad reading on crank .

nocoolusername

I put this question out there asking for help because I have exhausted my knowledge. how do you know I did not check timing on the distributor? I listed what I have replaced so far, not the hours of fiddling and adjusting I have done.

I have used a noid light on the fuel injectors to check pulse. I have pulled and restabbed the distributor several times. I have restabbed it 180 out and 1 tooth either direction of tdc both ways with no success. Yes I have checked that i have spark at all of the cylinders. I replaced the o2 sensor when I bolted the engine in. I also replaced the fuel filter.

why should I not have rebuilt the engine? I found when I rebuilt the engine that I had some significant cylinder wear, and the exhaust valves and seats in the head were bad. I also wanted to put a new cam in it to boost the power, the valve cover gasket and rear main seal were leaking oil all over the place, and as I said in my initial post I did not rebuild the engine to fix the no start problem. I did it because I had planned to rebuild it anyway and I decided to just start from scratch with a fresh clean engine so that at least I would not be wallowing in grease while I was working on it.

If you look at the picture I posted this is where the rotor is when the engine is at tdc. I checked it 180 out and it would not even fire.

at this point I am very frustrated, if anyone has any suggestions I appreciate it. snide comments however not so much.

nocoolusername

thanks. I checked it one tooth either way several times. and I put a new harmonic balancer on it when we rebuilt it and verified that the timing mark was at zero when the number one cylinder was at tdc and the 2 marks on the new timing chain were lined up, before we put the head back on.

mcguyver_xj

ok i was only trying to help i was not putting out any snide comments i was just verifying left out details because in your original story its seems you were leaping over basics to throw parts at stuff that could have been waited on...

but as the other guy suggested pull dist. and reset cylinder #1 tdc on the compression stroke then put in dist. go from there...and while in there if you have an ohm meter i would do resistance checks on your vital sensors that would effect it running...(idle air control, cam position aka pick up coil in yours, crank position, map sensor, tps, and double check all your grounds since you had the engine out...

to the person who suggested 02 sensor that would be plausible in a 1996-and up jeep with OBD-II four wire 02 sensors but i am thinking this would only have a single or two wire and if thats the case it wouldn't effect it

nocoolusername

ok. sorry and I appreciate the help. and I am sure I must have jumped over some basics because it still is not running. but I have been working on this thing so long without success that I am frustrated beyond tolerance. I have reset the distributor at least 10-15 times. in the picture above you can see where the rotor is when the engine is at tdc on the compression stroke. (and I have tried it 180 out too and it won't do anything but backfire.) currently the distributor is one tooth advanced from that position because I read that the trailing edge of the rotor should be at the left edge of the post.

if you have any information on how to properly test those sensors I would appreciate it. this is where I think my problem is. one of the sensors somewhere is not right. I replaced the distributor with the new cam sensor in it when we found it broken as one of the very first things we did. but I am not sure it is functioning properly. I do not know the proper testing method for these sensors. I know how to replace them but at this point I am chasing my tail looking to see what I have already done that may have been done wrong or what new part may have been defective out of the box. I need to know how to test these sensors so that I am not just replacing parts because they might be bad.

and thanks for the help.

Jamie57

You did everything I did. And I got the same results on a 91 limited I had.
It would only run for a short time (usually a few seconds) then quit.
I started pulling my hair out as this was NOT my first rebuild. more like my 50th and I was stumped. I screwed with it for 4 days as my wife wondered if I'd lost my mind.
Turns out that having unhooked and rehooked up the battery so many times that the "Factory security system" had engaged. I didn't even know it had one.
Apparently the fix is to take the door key, close the door insert key in lock, and turn it back and forth a few times.
Then put key in ignition and try again. Started right up and ran like it should have with a rebuilt engine and all new parts.

Alaskan89XJ

"...when we pulled the distributor cap off was that the insides of the distributor were in pieces. the cam position sensor etc. was broken".

Hmmm.., you certainly have a mysterious issue(s). Back in '88, winter, a tang, or dog ear, i.e., one of two, atop 258 cu.in. oil pump, where the male blade of the distributer shaft goes.., broke apart, away, thusly causing for running problem. When it sort of seemed to purr, for a few seconds at best, it would not move vehicle, and then back down to non run. When I pulled the distributor cap off, the rotor was mostly in pieces, but the contact part was still there enough to give some sportatic rotor connection to cap posts.

So, you had a mechanical distributor problem. Hard for me to believe that an electrical issue could cause that. I've seen stuff melt, fry, but never explode in a distributer.

However, you are way past that with a 4.0 rebuild, and as such with a new distributer. So, even though you have eliminated alot, have you replaced your oil pump? (I do not recall that in your listings). Perhaps if you pull your distributor, and look down in there with a good light, and take a look-see. Yeah, I may be reaching, lol, but I had exactly the same running condition as per your description, i.e., broken parts in dist., and same descriptive running condition.

Whatever your problem is, when you fix it, please let us all know how you fixed it, ok?

Jor2010dan

Hmmm... well, I would just unplug it. Under your dash (don't need to remove. ) on the passanger side of your steering colummn there is a box. It should have a pinkish plug (obd1 I believe) I remember getting my Jeep and I had to do that before mine would start. Long shot though.

Alaskan89XJ

FACTORY SECURITY SYSTEM? Really? Key back n forth in the door, and then ignition? Really? I will have to look in my FSM and see if there is some wire going to the door lock.., Hmmm... Well, at the very least, my XJ is basic, so I know that option ain't there, but I am amused that the FSS exists and can somehow be reset as described. Kind of neat! Hope it works for Nocoolusername.