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Cherokee No start

Cavalry

NAXJA Forum User
Location
ny
2000 cherokee 4.0
My dad bought it with a bad engine. picked up a engine from a reputible yard and put it in. He is no dummy when it comes to cars...just not to up to date with computer controlled as he should be. Well the damn thing wont start, so I inherit the problem. I dont know much about these jeeps so we end up here.

engine will crank fine, pops a little but will not start. If I were to guess I would say the timing is off.

I did a pretty good visual, no plugs off, checked every plug to make sure they were clicked. All fuses are good. Fuel pressure at rail is 50ish. MIL is off. Scanned the computer, no codes. Checked the data stream. only thing I noticed that struck me as odd was there was o deg ign advance while cranking. Which might be completely normal. I dont really get squat for info since the engine wont start.

about the only thing I can think of is a screwed up crank trigger?
 
Bet the distributor is 180 out.
 
Lets start a pool, and see who wins. I'm going with terrorists.

or the CPS , depending on where you live.


BTW 00 don't have distributors :D

Just that LOVELY coil pack thing.
 
old_man said:
Bet the distributor is 180 out.


its a distributor-less ignition?? the place where the dist once sat in the ancient days now has a sensor. I thought the same thing. On that sensor is a detent so it seems that it can only positioned in one place???

thats exactly what is feels (sounds) like though....ignition timing is waaaaay off
 
xjnation said:
Id bet the cps is the problem, drivres side bell housing tough to get too.
I can get to it ok...how do I test the CPS? I popped the cover there is about a 1/8" gap between the sensor and the pickup ring. I really dont want to go on a guess and replace the sensor route
 
langer1 said:
Do you have spark?
I dont have the special tool to go between the coil pack and plug... it pops and farts. its firing, jsut not in the correct place
 
Cavalry said:
I dont have the special tool to go between the coil pack and plug... it pops and farts. its firing, jsut not in the correct place
If you have spark the CPS is working. What did you say you had for fuel pressure? Did you bleed the air out?
 
langer1 said:
If you have spark the CPS is working. What did you say you had for fuel pressure? Did you bleed the air out?
it was around 50psi. I bled the air out of rail...if any is stuck between the schrader and injectors that is another story. I can smell fuel when as it cranks and tries to run.
 
Foto4x4 said:
Is it backfiring? Please clarify on the "popping"... thanks.


backfiring through intake, but not all the time, need to crank for 20 secs or so to get it to go through intake....cranks fast then slow pops though intake, feels like it is about to start but dosent. just like timing is off
 
Cavalry said:
backfiring through intake, but not all the time, need to crank for 20 secs or so to get it to go through intake....cranks fast then slow pops though intake, feels like it is about to start but dosent. just like timing is off
I had it similar to that on my camaro, and it was just like old_man said, distributor was 180 off. Since you don't have a distributor and Haynes repair manual says you can't adjust timing on the 4.0... I'm not familiar with the 00 ignition setup, but it sounds like you have spark plug wires. If so, check they are in the right order (not to make you sound dumb or anything, just simple mistakes happen). Was the #1 cylinder set at TDC when the ignition system was put on, or similar. Check/Re-check anything that has to do with the firing order, that's what my money is on.

EDIT: scratch spark plug wires, of course you don't have wires, what was I thinking. Is the coil rail reversed?
 
Last edited:
Foto4x4 said:
EDIT: scratch spark plug wires, of course you don't have wires, what was I thinking. Is the coil rail reversed?


i dont see how you could reverse the coil pack? plug is to the rear, not enough wire to go to the front. I would assume thats how it goes???
 
Last edited:
Foto4x4 said:
Was the #1 cylinder set at TDC when the ignition system was put on, or similar.


ok this one baffles me? what do you mean by that? do you have to reset the igniton system??????
 
Anyone have a clue why it dosent just pop a code? there is something wrong here why cant the computer figure it out?
 
Cavalry said:
ok this one baffles me? what do you mean by that? do you have to reset the igniton system??????
What I mean is that if the ignition system was removed and the crankshaft moved, the pistons will be out of order with the firing sequence. Since you have no distributor I can not be sure setting the #1 cylinder to Top Dead Center is required. I'm just throwing ideas out there.
 
Cavalry said:
I can get to it ok...how do I test the CPS? I popped the cover there is about a 1/8" gap between the sensor and the pickup ring. I really dont want to go on a guess and replace the sensor route
That don't sound like the CPS, what cover are you talking about? The CPS is on the bell housing.
 
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