2000 Jeep Cherokee Classic

[sinistr]

I was chasing a random misfire issue with the 4.0l 6 in the jeep. It had no rhyme or reason, it would happen at idle, it would happen at speed. Apparently its a common issue, sometimes caused by heat soak caused by the close proximity of the #3 injector to the exhaust manifold. I wrapped the injectors in heat resistant boots(problem was still there), replaced the MAP sensor,(problem was still there). I did some more research on the issue and found that a faulty Crank position sensor could cause the issue, I changed that as well( and by the way whomever the engineer was that decided to put the crank position sensor in the 11 o'clock position on the bellhousing and then only leave 3" of clearance to access it needs to be kicked in the nuts)and I changed the ignition coil rail. So far so good its seems to have fixed the issue.

Yes the CEL was illuminated and the codes read cyl#1 coil, cyl# 1,4,6 misfires.

[sinistr]

Well it didn't fix the problem. It ran ok for a couple days and then came back. Some days its worse then others. Today I replaced the plugs,the fuel injector to cyl #1,1 O ring for the injector for cyl #4. I also changed the oil and flushed the coolant. Well the issues still exist. I ordered a cam position sensor,should be here in a few days.

[Orangepeel815]

Jeeps you got to love them

[RTCHAS]

Its a Jeep Thing! LOL

[sinistr]

Issue is still present and getting worse. I'm tossing around the idea of parking the jeep and buy another vehicle to use for work. The jeeps 11 years old with 94000+ on her and there's a bunch of things that I should tend too. We bought her new (Trish's first car).

[TrueBlue]

It sounds like maybe you should retire the old girl.

AKA - Dave

[sinistr]

Well I finally found out what is wrong with the jeep. Jeep 4.0l have an issue where the exhaust valves do not rotate like they are supposed to. This is prevalent in the 98-05 heads 0331. The valve sits in one spot creating carbon build up and eventually burnt valves. I have the issue on cyl#'s 1&6, so it looks like I'll be pulling the head off and getting the head redone with hardened seats for the exhaust valves. I figured since it will be apart I might as well do the timing chain and water pump. Looks like I'M buying a new car for work this week. This will give me a chance to go through the jeep and make it 100% again.

[RTCHAS]

Ouch! That sucks! Time for a stroker motor ! With a Header and 4Bl

[Series 5]

I'm with Chas, can you say future off-road Beast.
Put some bigger sodium filled stellite valves and exhaust seats in the heads and bottle feed that mountain goat!
Besides the extra power is great for getting on the highway from the on ramps.

[sinistr]

Dropped the head off at the machine shop for hardened exhaust seats and a valve job.

[sinistr]

Working on the Jeep today, going to finish up the bottom(pump, rear main, pan gasket) . The top is all done, it got :
I got the head redone(valve job, new springs, etc)
New timing chain, new waterpump, thermostat, coolant temp sensor, oil filter housing o rings, gaskets, a/c lines, radiator, hoses, etc.
After this I'm doing u joints, front rotors, and 4 new tires.

I may do a 2-3" lift we will see what the boss says ( it is her Jeep )

[RTCHAS]

What no pic's? I dont believe you.

[sgt tunez]

Haven't even started on my Jeep yet. Just reached 156,000 miles.

[sinistr]

It's runs! Had her running for awhile yesterday,coolant level was good, great oil pressure. I still have some small kinks to work out with it. The steering stabilizer will be in on Thursday and then I will move onto the front rotors.

[RTCHAS]

Cool good stuff I still have not finished the ramcharger! Need to get some sort of kick down on it! And then play with air cleaner and few other things never end's. Good work on getting it running again.

[sinistr]

Oh how I hate this f'n jeep. Brand new radiator, in the jeep for a month, starts to leak. Last week it ran for 45 minutes in the driveway, today its throwing codes and stalling. It started to misfire and shutoff. It wouldn't restart until I cleared the codes. Checked the fuel discharge at the port(little to no pressure ) It would idle but stumble and die if I fever it up. Seemed like it was running out of fuel. So I drop the tank and replace, the pump and filter. It fired up, ran for a few seconds and then stumbled and died. I had to walk away.
As much as I love cars, sometimes I can't stand them. Right now I want to sell the Jeep, the Nova, and the Charger and be done with this bs.
Thank you for letting me vent, I know you guys understand.

[RTCHAS]

I feel your pain i have little to no time for BS it's depressing to find a problem like the oil leak I have on the Ramcharger from the rear of the motor? i did the same thing as you and just walked away! I hope it's not the rear main but til I drop the inspection cover and look I can't tell ! Ugh it will sux if I have to pull the motor all over again. You can really lose interest in it fast when sh%t go's south.

[Orangepeel815]

Sorry to here about the jeep . I feel the same way You fix something and something else happens it drives me nuts that why I just sold my jeep before I went really nuts.

[moddog]

I'm wondering if you have something in your fuel line, maybe you should try blowing it out. The Ramcharger that I had would do that and it was the fuel filter. I had one of those fine mesh glass filter on it. Seeing that you changed your pump and filter I would check the fuel line.

[sinistr]

It's got good fuel pressure at the line now. I'm thinking maybe from it heating up and cooling down multiple times that it may have loosened up the intake manifold bolts and is causing a vacuum leak. I don't hear a vacuum leak but it could still be there. On the 4.0l 6 the intake is right above the exhaust manifold and they share some of the same mounting bolts. I did find the coolant leak, it's coming from around the bung for the lower transmission cooler line in the radiator.

Chas I hope that your leak is just something simple like the pan bolts loosing up from expansion and contraction.

I've got a Baptism to attend today so no car playing, maybe that's a good thing.

[RTCHAS]

It's got good fuel pressure at the line now. I'm thinking maybe from it heating up and cooling down multiple times that it may have loosened up the intake manifold bolts and is causing a vacuum leak. I don't hear a vacuum leak but it could still be there. On the 4.0l 6 the intake is right above the exhaust manifold and they share some of the same mounting bolts. I did find the coolant leak, it's coming from around the bung for the lower transmission cooler line in the radiator.

Chas I hope that your leak is just something simple like the pan bolts loosing up from expansion and contraction.

I've got a Baptism to attend today so no car playing, maybe that's a good thing.

Those manifold bolts could do it what codes did it trip?
I hope it's the pan I had trouble getting the pan to fit right (thank you china) I have to pull cover to get a good look at where it is from it isn't pissing out but after I drove it and it was Hot I had some drop's coming from the back and it isnt from top side I checked.

[sinistr]

Figured it out. When the oil pump drive housing is removed, the cam and crank position sensors need to be resynchronized or it will try and fire the wrong cylinders at the wrong time. Hence the cyl#3 coil code. I followed the procedure, remove the coil rail, plug#1,cam position sensor, and oil pump drive. Bring the engine up to TDC,reinsert the housing making sure that it doesn't rotate.Then put the rest of the parts on and fire it up. Good to go.

[RTCHAS]

Ahhh good find ! That will drive you nutz for sure!

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