masteroguitar

alright, I have a previous post that went on for days with updates of things that I tried to solve my issue I wanted to make a new post with all the steps I took to find the problem so someone else might be able to find this and save a ton of guess work and parts throwing.

I own a 1999 jeep cherokee sport 4.0L in line 6 cylinder with 280,000 miles on it.

(SYMPTOMS)
everything on my jeep worked fine until my wife went to drive it and it wouldnt go into reverse. she said she started the car, shifted into reverse and the engine just rev'd up and didnt move. she then shut down the jeep and tried to restart it and it died.

(STEPS I TOOK TOWARD A SOLUTION)
so first thing i did when i got home was try and start the engine, it cranked just fine no over spooling like a broken timing belt would do, nothing out of the ordinary just wouldn't fire.

then it started to get a bit confusing, I checked every single fuse and relay and everything checked out with my handy multi-meter.

checked the fuel line pressure with a gauge kit from auto-zone I rented and had 38lbs of pressure which is low, thanks to (tjwalker) I was informed it's supposed to be 49 psi +/- 5 psi. but unfortunately wasn't the root of my problem.

checked that the engine was getting air, it was. also sprayed starter fluid in the air intake. didn't work.

moved on to the ignition coil, took out the center post that goes to the distributer and grounded it to the engine with a small screwdriver and got a nice strong spark. (also shocked the living **** out of myself doing it, don't hold it when someone cranks the engine, bad idea)

after that I removed the distributer cover and made sure it rotated and functioning, it was.

removed the spark plugs and replaced with new ones for that fresh blue spark and checked each spark for functionality. still no engine start.

decided to replace the distributer cap and rotor because they did have some wear and tear (at this point I was just throwing parts at it) also didn't work.

then I thought it was the crankshaft position sensor (cps) followed a guide I found online to test it and it failed, replaced that as well and still no engine start.

at this point I was 150$ into it and didn't have a solution. I then talked to a mechanic at work he said "did you check the timing chain?" I said I saw the rotor in the distributer rotate so there's no way it was broken. he then pointed out that if you have a high mileage chain or belt like I did it is possible for it to get so loose as not to break but jump timing.

went home and removed the spark plug from the first cylinder and looked in with a flashlight while a friend rotated the engine by hand to get the cylinder all the way up to the top. what I believe they call the "compression stroke".

while it was in that position I opened up the distributer cap to see if it was aligned with the first cylinder post that goes to the spark plug and sure enough, it was not, it was lined up with the third cylinder.

so no matter what I replaced or how hard I tried the engine would never fire up.

ordered my parts online and replaced the timing chain and gears, re-aligned the timing on the distributer and she fired right up.

so what i learned from this, even if the timing chain isn't broken it can still be out of sync. hope this helps others with a similar issue.

here are the links to all the info I looked up.

checking for spark:

checking fuel pressure:

distributer timing (very well done)

timing chain replacement

nujeepguy

4.0L v6 with 280,000 miles on it....not v6 huh?
but 280000 is good news, hope mine lasts that long!!

tjwalker

Just so you know for reference, the fuel pressure spec. for the 99 is 49 psi, plus or minus 5 psi, so your 38 psi, while it may not be giving you problems now, is out of spec low.

DFlintstone

It's an inline, (straight) 6, just a little typo there. masteroguitar, curious, did you check the alignment of the sprockets first and find it to be off, slipped?

masteroguitar

To tell you the truth I just went off what a mechanic friend said. Dropping the fuel tank to get to the pump and filter doesn't sound fun but neither does a stalled vehicle. Looks like I have another addition to my list of fixes. Thanks for the tip!

masteroguitar

Hey I didn't realize I said that, I'm not very good at the exact terms for things sometimes, I will edit this to reflect that. And no I just reset the timing based on the cylinder and rotor to make sure that was the issue once I had the engine running for the few seconds that it did I figured that slipping was the issue. When I finally tore it down and saw the chain you could pull it by hand and make it slip.

DFlintstone

Thanks! I guess that settles any doubt! Sometimes it's a little like shadows, smoke and mirrors. Most books and diagrams show the wire locations on the dizzy incorrectly, (#1 Being at 5:00 viewed from the side). Then the mark on the crank pulley can move if the outer ring slips on deteriorating rubber. Then just indexing the dizzy right is another task. Then is does seem rare a chain on a 4.0 straight six slips. 280K on one of mine and it's fine....here though we don't need to use sewing machine oil!

Well sluthed! And the crowd cheers! Glad you found it, (and then nailed it)

You might Google and find photos and stuff CCKen has on your pump. Guess there are three filters in there? Also he made a nifty hatch to access his without dropping the tank.

masteroguitar

thanks! and ya 280000 is pretty good, funny story about this car. about 6 months ago I had this vehicle stolen, I still had the keys and there was no damage to the steering column, but anywho it was found a few months later and since then I've developed the jeep shake, a transmission leak, and this timing issue. don't know what they did but they had some fun with it. but aside from that, luckily I work for a welding fabrication shop and can build a nice hatch, that's a great idea. long as i don't catch it on fire

masteroguitar

heh heh ya I'm a self repair newbie so every car is a v something I mean L6 cylinder.

BlueRidgeMark

Bosch or... I think it's Carter are the recommended pump. I'm certain of Bosch, maybe someone else can conform or correct the other?

DFlintstone

I'm still eligible for a Darwin Award. (my welding on gas tanks didn't take me out before I could reproduce, yet!) Somewhere someone posted cutting the hatch thing with the tank still in. Dremel? I don't know any Nasscar drivers with a spare fire suit. I DO have extinguishers and a field, but alas, nobody to put me out after I try that.

DFlintstone

I did a little googlen, guess the thick plottens....see post #9, #9 > https://www.cherokeeforum.com/f2/cra...l-pump-227511/