Bad miss in reverse, 98 4.0 Cherokee

[joeb]

I know this is the wrong place for Cherokee problems but it seems there is more participation here. Sorry.

I have a bad miss / shudder in reverse. I bought this 98 4.0 6 months ago and it had the same problem but the dealer put a new distributor cap and rotor and it fixed the problem. Now it's doing it again.

I put a new Accel dist cap and rotor and and new plugs and wires but the problems still persists. The only code it ever throws is 305, missfire in clyinder # 5. A new injector in #5 was replaced 6 months ago because that's the code it was throwing then but the cap and rotor fixed. I'm baffled.

Any advice would be appreciated.

JoeB

 

[84cjseven]

How about a new plug in #5. maybe it is fouled or something from the misfires. Only in reverse huh. Thats strange. Is there a rev limiter in it like a 4 wheeler?

 

[84cjseven]

Sorry I see you did put new plugs. Move the injector to another cyl and see it misfires.

 

[joeb]

Yep, all new plugs. I swapped Bosh's for the stock Champions. This is a 4 wheeler. Rev Limiter.... I'm in the dark here.

JoeB

 

[54cj3b]

do away with the bosh plugs ,
go back to champion youll get better performace the 4.0 dont like the bosh plugs for some reason think its becaus they dont burn hot enough

this is a double post both in cj forum and xj read the posting rules before posting !!!!!!!
http://www.jeepz.com/forum/forum-related/19343-jeepz-com-rules.html

 

[joeb]

That's what I did. I worded it poorly but I put the Champions in. The bosh plugs looked perfect though.

What's the problem with it only missing in reverse though?

Thanks
JoeB

 

[glenn beck]

any chance the wire harness is being nipped or near something hot. the scanner can only tell that theres a problem not where the problem is. my brother-in-law had 3 single point injectors changed on his car before he quit and gave it to me (threw keys and said keep the pile of it). i looked and the wiring to the injector was melted to the manafold. i repaired the wires and gave the car back and 2 years on its been good as gold.

 

[joeb]

One more thought. Why just in reverse. Makes no sense.

 

[84cjseven]

Any chance it is a transmission problem? Or is it a distinct engine misfire.

 

[joeb]

No, it's a distinct miss.

 

[SteelHeadz]

Check the O2 sensor wires for rubbing on the exaust. Just a thought.

 

[54cj3b]

That's what I did. I worded it poorly but I put the Champions in. The bosh plugs looked perfect though.

What's the problem with it only missing in reverse though?

Thanks
JoeB

bosh plugs burn hotter /also check plug wires both at cap and the plugs

 

[Vlad]

I have an 88 xj wag., it's my wheeling rig, a few years ago I had a broken motor mount and when I would put it in reverse it would torque the engine and cause it to miss out, it would kind of surge and almost die, and then surge again over and over. I never did figure out what the exact problem was, my theory was it somehow pulled on the cps or it's plug. Anyhow, I changed out the broken motor mount which no longer let the engine jump when in reverse and the problem went away.

 

[volaredon]

I wouldn't use Bosch plugs if I was GIVEN a semiload of them! JUNK JUNK JUNK Other things from bosch..... some but plugs? Get em outta here!

 

[Bounty__Hunter]

If you would post this in the XJ forum it wouldn't seem near as quiet.