1996 XJ Misfire Problems

[Talyn]

x2 see if you have voltage at the injector connectors now.

 

[my1996xj]

Well I have correct voltage to all of the injectors, All of the plugs have been replaced 2x, and the cap and wires are brand new???

 

[Talyn]

How do you know that your compression is good?

Also, just because apart is new, doesn't mean its good. How did you check for spark at each cylinder?

 

[Bobby@Bullydog]

Why cant everyone make a post that contributes to a guys issue at hand and help resolve the issue with past experiences rather than haze him about how he checks things.

Compression will not cause a random misfire...

Mine runs great sometimes..and then the CEL comes on and bam it runs bad....its most likely an electrical issue I have yet to track down but at least try to help a guy out rather than poke at him.

 

[my1996xj]

Thanks Bobby!

I used a compression tester and all was good on that front!!

The plug in 6 seems to be very black at the tip, I have put in 2 sets of plugs and 2 sets of wires so i am very doubtful that they could both be bad in the same spot.

 

[Bobby@Bullydog]

Im fixing to swap out ECMs with my neighbor and see if it fixes my problem.

 

[my1996xj]

I wish I had that one that easily accesible!! Well i went ahead and pulled my plugs again...Now #6 is pretty charred at the end and #3 looks oily!!

 

[heavyequipment]

Buy a "noid light" to test power to your injectors. They are cheap, handy, and come with instructions. Basically, you plug the light onto the plug you disconnected from the injector. Start the engine and see if the light flashes. If it's steady or stays off you have a wiring or computer problem. I suggest this because it's a cheap and easy way to eliminate wiring or computer problems.

 

[Talyn]

Why cant everyone make a post that contributes to a guys issue at hand and help resolve the issue with past experiences rather than haze him about how he checks things.

Lets see.. according to him he has spark, good compression, fuel, proper power to the fuel injectors and the fuel injectors are good.... maybe his test methods are wrong, or he isn't as knowledgeable about this sort of thing. As for compression, what did he change that this issue came about after? The head gasket, which if there was a problem could lead to poor compression. Ans he said that he has a rough idle 100% of the time... its most likely that the engine is having a slight misfire (which the computer may or may not report) then at times a complete misfire.

No one is hazing anyone, grow a thicker skin.

 

[Bobby@Bullydog]

Lets see.. according to him he has spark, good compression, fuel, proper power to the fuel injectors and the fuel injectors are good.... maybe his test methods are wrong, or he isn't as knowledgeable about this sort of thing. As for compression, what did he change that this issue came about after? The head gasket, which if there was a problem could lead to poor compression. Ans he said that he has a rough idle 100% of the time... its most likely that the engine is having a slight misfire (which the computer may or may not report) then at times a complete misfire.

No one is hazing anyone, grow a thicker skin.

Of course he isnt knowledgeable about it...thats why he made this thread...to get someones help that might have experienced this problem before. Im new to Jeeps myself as this is my first one. Each vehicle has those certain things that go wrong with them no matter what and everyone knows how to fix it if they have been around them long enough.
Ask me anything about a Foxbody, Cummins, or a Powerstroke and i can tell you what to fix...Ive built too many to count.

So be nice and help the guy out without being a doucher...just sayin

 

[Talyn]

Thanks Bobby!
The plug in 6 seems to be very black at the tip, I have put in 2 sets of plugs and 2 sets of wires so i am very doubtful that they could both be bad in the same spot.

True, i didn't see that you put in a second set of wires.

When you say chared on #6 you mean its black with carbon? If so for some reason its running rich. And #4, are you sure it is oil and not just wet fuel?

 

[Talyn]

So be nice and help the guy out without being a doucher...just sayin

I am being nice, I am trying to help him, which you don't appear to be doing. The only person that is a "doucher" here is you.

 

[Bobby@Bullydog]

I am being nice, I am trying to help him, which you don't appear to be doing. The only person that is a "doucher" here is you.

I cant help him other than tell him what Ive changed..Ive got a similar issue with mine and still haven't figured it out. But as soon as i swap out my ECM with the neighbors ill let him know if it fixed my issue or not.

 

[joe_peters]

Black "fluffy" = too rich.

Wet = oil or not firing the air/fuel.

 

[my1996xj]

Since we seem to have a few people replying let me go through the scenario again:

Engine Codes p0300,p0304

Idles rough, smooths out from 5-45mph and then runs like crap from 45-65

#6 Plug Black end, looks burnt(plug is less than a week old)

#3 Plug now oily

Recent repairs: New Headgasket, Water Pump, Therm, Plugs(x2), Wires(x2), Cap and Rotor.

The compression is good across the board, all the injectors are working.

I took auto mechanics classes 10 yrs ago, so I know some but am a little Rusty!!

Thanks!!

 

[my1996xj]

Also the exhaust has a sputter sound to it and seems to be dropping too much ray fuel out of the ehaust pipe

 

[my1996xj]

Well, after getting a call from my mechanic I finally have some info(all Bad!!). He came out and ran another compression check-

Cyl 1 130
Cyl 2 130
Cyl 3 130
Cyl 4 0
Cyl 5 120
Cyl 6 60

Looks like it's time for a new Motor!!

 

[joe_peters]

You sure about the head gasket repair?

 

[my1996xj]

At this point I am becoming unsure about everything on this Jeep! I guess I have no choice but to tear it down and check everything!

 

[Talyn]

Well, after getting a call from my mechanic I finally have some info(all Bad!!). He came out and ran another compression check-

Cyl 1 130
Cyl 2 130
Cyl 3 130
Cyl 4 0
Cyl 5 120
Cyl 6 60

Looks like it's time for a new Motor!!

That sux. You should take it apart and examine it before you jump to the conclusion of needing a new engine. Could be something as simple as needing a valve job. A leak down test would also be a good idea to perform before tear down though. That way you know which end to examine.

Refresh my memory, how did it run prior to replacing the headgasket?

Why cant everyone make a post that contributes to a guys issue at hand and help resolve the issue with past experiences rather than haze him about how he checks things.

Compression will not cause a random misfire...

Open mouth, insert foot.