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89 Cherokee 4.0

#1

exotion

exotion

So my jeep has some new problems and I'm having trouble figuring it out this time. So alternator went out and I replaced now probably unrelated the car barely idles maybe 150 rpm Sometimes stalls while I'm .looking in there. Lots of hesitation on acceleration no power and back fires randomly quietly inside the engine bay. I have replaced plugs wires cap and rotor cleaned distributor check everywhere for vacumn leaks ran heavy dose of seafoam through air intake to clean throttle body and chambers. I am thinking egr valve or tps but am tired of throwing money at it. Also thinking timing but don't have tools to test or fix that I know this is a lawn mower forum but I'm stuck and hopefully someone has something for me to try


#2

Carscw

Carscw

Ok so it was running fine then the alt went out. You replaced alt started the engine and it ran like crap?

Did you unplug something and not plug it back up?

Unplug the tps and see if it changes at all.
Unplug and clean every plug up.


#3

Carscw

Carscw

Does it backfire out the intake?


#4

exotion

exotion

Carscw said:
Does it backfire out the intake?
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Sounds like it had the cat tested and its ok to


#5

Carscw

Carscw

As a rule popping out the intake is timing is off. Others things could be a bad valve a flat spot on the cam but would have started running bad over time.

I will assume you did not move the distributor.

I would retrace my steps and make sure everything is hooked tight and clean.

Then I would move the distributor and see what it does. Best way to time a engine is hold it at half throttle and turn the distributor until the engine runs smooth.


#6

exotion

exotion

Carscw said:
As a rule popping out the intake is timing is off. Others things could be a bad valve a flat spot on the cam but would have started running bad over time.

I will assume you did not move the distributor.

I would retrace my steps and make sure everything is hooked tight and clean.

Then I would move the distributor and see what it does. Best way to time a engine is hold it at half throttle and turn the distributor until the engine runs smooth.
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I didn't move it I don't think I've never done timing before is sounds fine with me holding throttle at idle it doesn't can I do it at idle and how to I move it.?


#7

exotion

exotion

Also this is a fuel injected model and my haynes doesn't say anything about moving the.distributor so I'm double blind lol


#8

Carscw

Carscw

Have you made sure everything is plugged in


#9

exotion

exotion

Carscw said:
Have you made sure everything is plugged in
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Ya been over all the electrical nothings seems unplugged, I probably emptied 3 cans of carb cleaner looking for vac leaks


#10

Two-Stroke

Two-Stroke

You could also look at all the small hoses (rubber tubing) that connect to the fuel system and the distributor. If those are original (1989) they could be rotten and touching them while you worked on the alt could have opened up a crack.

If you haven't touched the timing, I wouldn't mess with that until you exhaust other possibilities.

It also wouldn't hurt to sit down with the manual (I like Haynes -- have used them for years) and read the sections on the fuel system and the ignition. I'll bet the answer is in that book.

Is it really idling at 150 rpm? That seems so low.


#11

davbell22602

davbell22602

Do ya have enough tension with alternator on the engine belt? Belt might be too loose.


#12

davbell22602

davbell22602

Did ya buy the right alternator for it? Some vehicles have 2-3 different ones for the same the engine.


#13

exotion

exotion

Two-Stroke said:
You could also look at all the small hoses (rubber tubing) that connect to the fuel system and the distributor. If those are original (1989) they could be rotten and touching them while you worked on the alt could have opened up a crack.

If you haven't touched the timing, I wouldn't mess with that until you exhaust other possibilities.

It also wouldn't hurt to sit down with the manual (I like Haynes -- have used them for years) and read the sections on the fuel system and the ignition. I'll bet the answer is in that book.

Is it really idling at 150 rpm? That seems so low.
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Excatly it sits.down the and bounces between 150 to 500 I haven't touched timing and am a little intimated by it although in the haynes which in the troubleshooting section it breaks it down to the different symptoms and all the different symptoms point to ignition timing or vacuum I haven't cleaned the throttle body I wanted to but the imbesile who owned this thing previously stripped the three torx head screws holding the air intake tube to the throttle body. I could carefully pull the tps and clean it and the egr has my attention now it shows sake symptoms I am having but so did the plugs wire caps rotor ... I have a bad feeling carscw is right with the timing and I don't have the tools or knowledge to deal with it and I don't really wanna spend a lot of money at a shop :(


#14

exotion

exotion

davbell22602 said:
Do ya have enough tension with alternator on the engine belt? Belt might be too loose.
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Belt feels good and its the right alt voltage is good on dash and napa hooked me up this is the third one I've put in I am pretty sure they are unrelated at this point. I disconnected the wires and clamped them together to reset computer while I trickle charged the battery about 30 mins. When I sit in I can turn on all my acesorys and then turn them off and the voltage goes back to normal


#15

Mike88se

Mike88se

exotion said:
So my jeep has some new problems and I'm having trouble figuring it out this time. So alternator went out and I replaced now probably unrelated the car barely idles maybe 150 rpm Sometimes stalls while I'm .looking in there. Lots of hesitation on acceleration no power and back fires randomly quietly inside the engine bay. I have replaced plugs wires cap and rotor cleaned distributor check everywhere for vacumn leaks ran heavy dose of seafoam through air intake to clean throttle body and chambers. I am thinking egr valve or tps but am tired of throwing money at it. Also thinking timing but don't have tools to test or fix that I know this is a lawn mower forum but I'm stuck and hopefully someone has something for me to try
Click to expand...
I owned a couple of XJ's but it was a long time ago. I did do all my own wrenching so maybe I can recall something. Start at the beginning. Were these problems present before you replaced the alt?
EGR is easy enough to test. Pushing up on the diaphram should do it. There's probably also a EGR solenoid tho. An old TPS is basically an on/off switch. Use a meter to test for continuity at closed throttle and open throttle. Should be continuity at closed and then break when its opened. Timing... valve timing could be off a tooth if the chain stretched but not likely. If you didn't touch the distributor hold down then ignition timing should be same as it was. Like somebody mentioned it sounds like a vac/intake leak. Isn't there a rubber intake boot? Check that.
If it ran good before recheck all your steps. Oh and if you ran 3 cans of Seafoam through the intake you may need a new o2 sensor or even a cat convertor sometime.


#16

exotion

exotion

Mike88se said:
I owned a couple of XJ's but it was a long time ago. I did do all my own wrenching so maybe I can recall something. Start at the beginning. Were these problems present before you replaced the alt?
EGR is easy enough to test. Pushing up on the diaphram should do it. There's probably also a EGR solenoid tho. An old TPS is basically an on/off switch. Use a meter to test for continuity at closed throttle and open throttle. Should be continuity at closed and then break when its opened. Timing... valve timing could be off a tooth if the chain stretched but not likely. If you didn't touch the distributor hold down then ignition timing should be same as it was. Like somebody mentioned it sounds like a vac/intake leak. Isn't there a rubber intake boot? Check that.
If it ran good before recheck all your steps. Oh and if you ran 3 cans of Seafoam through the intake you may need a new o2 sensor or even a cat convertor sometime.
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I seafoam regularly I replaced 02 sensor last year and I had cat tested and its good I'm going to cut it out anyway assuming this thing gets running I know nothing of egr valves I've read alot and online makes it sound simple but the haynes makes it sound like I need to almost pull the engine to check and some vac tester equipment


#17

M

mullins87

Are you certain the battery is good? What about the cables? You disturbed the cable going from the alternator to the battery when you changed it out, you could have also disturbed the other battery cables in the process. Jeeps are notorious for running poorly or not at all when the battery appears fine. Your battery could be weak, also could be the reason the alternator crapped out.


#18

exotion

exotion

mullins87 said:
Are you certain the battery is good? What about the cables? You disturbed the cable going from the alternator to the battery when you changed it out, you could have also disturbed the other battery cables in the process. Jeeps are notorious for running poorly or not at all when the battery appears fine. Your battery could be weak, also could be the reason the alternator crapped out.
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Alt went out because of bad bearing that has been whining for about a year lol I tested battery its good besides I left it on the trickle charger for about 24 hours after draining the battery on the tow home. I checked all the wires to and from alt and battery haven't gotten a chance to get in it today my wife wants me to take it .to a shop ugh .....


#19

Mike88se

Mike88se

Haynes is great but not perfect. You shouldn't need to have special tools to check the EGR but I don't think that's the problem anyway. I know they go out but I've never had it happen. And when a vehicle runs good til after you work on it it's almost always something you can find by retracing your steps. I'm still thinking a vac line or sensor connector or intake leak. Might want to check the sparkplug cable routing just to be sure.
This site might be useful: Jeep Cherokee XJ EGR Function Testing service manual download | Car Service Repair Workshop Manuals
That site also mentions a computer relearning thing when the battery is disconnected. I don't recall any relearning when I disconnected a battery but you never know from one car to the next. Good luck!
exotion said:
I seafoam regularly I replaced 02 sensor last year and I had cat tested and its good I'm going to cut it out anyway assuming this thing gets running I know nothing of egr valves I've read alot and online makes it sound simple but the haynes makes it sound like I need to almost pull the engine to check and some vac tester equipment
Click to expand...


#20

exotion

exotion

Mike88se said:
Haynes is great but not perfect. You shouldn't need to have special tools to check the EGR but I don't think that's the problem anyway. I know they go out but I've never had it happen. And when a vehicle runs good til after you work on it it's almost always something you can find by retracing your steps. I'm still thinking a vac line or sensor connector or intake leak. Might want to check the sparkplug cable routing just to be sure.
This site might be useful: Jeep Cherokee XJ EGR Function Testing service manual download | Car Service Repair Workshop Manuals
That site also mentions a computer relearning thing when the battery is disconnected. I don't recall any relearning when I disconnected a battery but you never know from one car to the next. Good luck!
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Ya I did the computer relearning ill look at the egr tom if it is vac or intake I can't find it like I said I emptied 3 cans of carb cleaner looking


#21

Mike88se

Mike88se

Okay... 3 cans of carb cleaner not seafoam :ashamed: If it's intake, you won't need carb cleaner and I don't think it's a small vac leak. I think it would need to be a big leak to cause all that. The 4.0 is a good engine and pretty easy to work on. Lots of room under the hood. My ZJ had a self diagnostics you could run using the ignition key. Not sure if the XJs had that. But then my ZJ had a problem that didn't show in the test and took me weeks to figure out the ecu had 2 fried capacitors ;) Bought new ones from Radio Shack and soldered them in and never had another problem.
Have fun ;)
exotion said:
Ya I did the computer relearning ill look at the egr tom if it is vac or intake I can't find it like I said I emptied 3 cans of carb cleaner looking
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#22

exotion

exotion

Mike88se said:
Okay... 3 cans of carb cleaner not seafoam :ashamed: If it's intake, you won't need carb cleaner and I don't think it's a small vac leak. I think it would need to be a big leak to cause all that. The 4.0 is a good engine and pretty easy to work on. Lots of room under the hood. My ZJ had a self diagnostics you could run using the ignition key. Not sure if the XJs had that. But then my ZJ had a problem that didn't show in the test and took me weeks to figure out the ecu had 2 fried capacitors ;) Bought new ones from Radio Shack and soldered them in and never had another problem.
Have fun ;)
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I have thought about and haven't pulled the ecu.. if my alt has been going out for a long time like I said the bearing whined for about a year about 7500 miles I am wondering if it put out less power while it was whining then when I put a new one on the different amperage could have friend something in the ecu

Also when it went out the bearing seized and pulley with it my wife continued to drive it squealing like a mofo for a couple mins if that extra strain on the belt threw off something. I couldn't even turn the pulley at all when I got the old alt off.

Another thought is that the transmission clunks when in drive and stopped at a stop light I think that's the torque converter but possibly flywheel and if it is flywheel could that throw my engine power for a loop


#23

Mike88se

Mike88se

I think your ecu is probably fine. There was a little problem with Jeep XJ and ZJ ecu's but not widespread. I don't think driving it after the bearing seized would do anything except kill the belt.
Pretty sure nothing in the transmission would cause this.
I'm still thinking its something simple... maybe not easy to find but simple ;) A plugged up cat could cause something like that too. I know you checked it a while back but if you don't have emissions testing ... :thumbsup:
In TX any vehicle over 25 years old doesn't need to pass emissions. Legally we'd still be required to have a cat and a punched out cat can be noisy.
exotion said:
I have thought about and haven't pulled the ecu.. if my alt has been going out for a long time like I said the bearing whined for about a year about 7500 miles I am wondering if it put out less power while it was whining then when I put a new one on the different amperage could have friend something in the ecu

Also when it went out the bearing seized and pulley with it my wife continued to drive it squealing like a mofo for a couple mins if that extra strain on the belt threw off something. I couldn't even turn the pulley at all when I got the old alt off.

Another thought is that the transmission clunks when in drive and stopped at a stop light I think that's the torque converter but possibly flywheel and if it is flywheel could that throw my engine power for a loop
Click to expand...


#24

exotion

exotion

Mike88se said:
I think your ecu is probably fine. There was a little problem with Jeep XJ and ZJ ecu's but not widespread. I don't think driving it after the bearing seized would do anything except kill the belt.
Pretty sure nothing in the transmission would cause this.
I'm still thinking its something simple... maybe not easy to find but simple ;) A plugged up cat could cause something like that too. I know you checked it a while back but if you don't have emissions testing ... :thumbsup:
In TX any vehicle over 25 years old doesn't need to pass emissions. Legally we'd still be required to have a cat and a punched out cat can be noisy.
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No the cat was my original diagnoses I took it to a muffler shop to test they pressure tested it said its good but my muffler has a hole that needs fixed tho lol it has to be something simple but I have looked and looked. I did notice that one of my injectors is kinda touchy if you put any pressure on it it leeks gas but doesn't if you don't touch it. So another thing on my list are mustang 5.0 injectors but again not investing untill its running


#25

Mike88se

Mike88se

Process of elimination ;) I'd skip the Ford injectors unless they have the same flow rate and are a direct fit. And unless you can reprogram the ecu and fab new fuel rail and get more air in the intake. Gotta keep that a/f ratio right.
exotion said:
No the cat was my original diagnoses I took it to a muffler shop to test they pressure tested it said its good but my muffler has a hole that needs fixed tho lol it has to be something simple but I have looked and looked. I did notice that one of my injectors is kinda touchy if you put any pressure on it it leeks gas but doesn't if you don't touch it. So another thing on my list are mustang 5.0 injectors but again not investing untill its running
Click to expand...


#26

wjjones

wjjones

exotion said:
Ya been over all the electrical nothings seems unplugged, I probably emptied 3 cans of carb cleaner looking for vac leaks
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But was it running good when you changed the alternator?


#27

exotion

exotion

wjjones said:
But was it running good when you changed the alternator?
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Yes. I dropped it off at the shop this morning my wife was griping so its no longer my problem


#28

davbell22602

davbell22602

exotion said:
Yes. I dropped it off at the shop this morning my wife was griping so its no longer my problem
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I hate see that repair bill. Probably gonna be a $500 or more bill.


#29

exotion

exotion

davbell22602 said:
I hate see that repair bill. Probably gonna be a $500 or more bill.
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Well the guys shop is litterly a block away and I do landscape work for him and last time I needed help I bartered labor work so I only paid for the part


#30

wjjones

wjjones

exotion said:
Well the guys shop is litterly a block away and I do landscape work for him and last time I needed help I bartered labor work so I only paid for the part
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Let us know what he figures out.


#31

exotion

exotion

Aparently the low voltage burned my fuel pump that I replaced a month ago so he got parts warranty to replace parts and I owe him a core aeration in the spring for labor :) lol dumb... I measured fuel pressure and it was good ...


#32

wjjones

wjjones

exotion said:
Aparently the low voltage burned my fuel pump that I replaced a month ago so he got parts warranty to replace parts and I owe him a core aeration in the spring for labor :) lol dumb... I measured fuel pressure and it was good ...
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Well its just good you got it fixed.:thumbsup: And thats not a bad deal for the labor.


#33

Mike88se

Mike88se

Hmmm, never heard that one. I've heard of dying alts taking the battery with then but not the fuel pump. I dropped the tank and replaced the fuel pump on my ZJ. Took about 2 hours but it was dark and I did it alone. The XJ might not be so easy. Glad you got it fixed.
exotion said:
Aparently the low voltage burned my fuel pump that I replaced a month ago so he got parts warranty to replace parts and I owe him a core aeration in the spring for labor :) lol dumb... I measured fuel pressure and it was good ...
Click to expand...


#34

exotion

exotion

Mike88se said:
Hmmm, never heard that one. I've heard of dying alts taking the battery with then but not the fuel pump. I dropped the tank and replaced the fuel pump on my ZJ. Took about 2 hours but it was dark and I did it alone. The XJ might not be so easy. Glad you got it fixed.
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You don't even need to drop the tank in xj just have to be careful of the sending unit when you pull it out lol


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