Hey guys (and Gals) Im stumped and I need ideas...
1995 xj sport inline 6 auto
When I get to highway speeds (55-60) and it kicks in to OD it starts to sputter and pop and basically struggle to maintain speed
I am currently trying to get it through DEQ so Ive been working on it
I replaced the TPS thinking that would fix it and nothing
it has some pretty bad blow by (oil on the air filter) Im going to be fixing this by replaceing the pvc and a new air filter but I dont think this is my problem
someone else told me it could be a bad intake manifold or just the gasket so I will try to torque that back down too.
any ideas or past experiences would be great to hear
Thanks, Brett

 

have you checked it for codes?

 

Check for a vacuum leak. I had a similar prob on my ol 93 xj after replacing the head gasket. Seems the stupid ***** mechanic(me) left a couple bolts loose on the intake. Torquing them back down fixed the problem. Could also be a dead spot in the TPS. I've seen that happen before too.

 

x2, also codes even if no cel light is present there could be stored codes

 

Its only thrown a code once and it went away Ill check it for stored codes and see what comes up... isnt there a way to check them without a scan tool?

I have checked the entire vac system in the past for leaks and its all tight I forgot to mention that in the original post.
Also it only does it with a load on the motor. I tried to get it to repeat the problem by holding it at about 2000rpm in neutral and that doesnt work
thank, I actually forgot about that code until now

OH and btw I dont think its a dead spot in the TPS because as mentioned its brand new and Im doubtful that the old and the new sensor have the same dead spot lol

Thanks again ill keep ya'll updated

 

1. Replace both of the CCV tubes/grommets, etc coming and going from the valve cover. They get clogged up and get brittle over time. These are available from the dealer for about $35. You need a clean CCV system to prevent oil from sneaking into your air filter box.

2. Check for stored codes. Post the exact codes here for comment if there are any. Below is a link for the "key-on, key-off" technique which will work with a 1995.

http://www.go.jeep-xj.info/HowtoECUcodes.htm

3. Check fuel pressure with a gauge at the schrader valve on the fuel rail. Compare your readings to factory spec. Gotta make sure that fuel delivery is verified.

4. Be sure tuneup hardware is up to snuff. Plugs, wires, cap, rotor, fuel filter.

 

Thanks tj that's great info I'll check the codes out tonight or tomorrow night
I'm pretty sure the fuel system is good to go because everything is fine in every other situation except freeway overdrive
I plan to do all the ccv system tonight and hope that will take care of it but we shall see

 

so I tried the "key on off" method to read the codes and it either doesnt work for my rig or there are no codes to show....
looking back I realize that this problem started when I replaced the leaky valve cover gasket so it probably has something to do with the ccv system it was too dark for me to pull the valve cover and replace the pcv so that will have to wait until I have the time what can I do about the other valve in the back of the cover? clean it? replace it?
thanks again, Brett

 

so it does it only when it goes into overdrive at 55-60

 

and are you sure that if those were missfires? may be "feeling" is same?

 

Yeah I'm sure. Up until this weekend it had no muffler on it and you can definitely tell its missing (the engine timing not the muffler lol)
To better describe it its more like hesitant sputter I'm going to get the ccv done asap

 

if its missing and it doesnt have the engine light on its probly a vaccum leak around the intake

 

should of at least showed 55 end of test

 

try replacing the cap and rotor, if thats not it then there is a very good chance your cam position sensor is bad. I had the same issue only alot worse, I took the cap(was new) off the distributor and cleaned the rotor ( was not new) and it fix it... I was scratching my head for a while and it turned out to be a simple fix...

When it starts to misfire, are you getting alot of pre detination ticking along with a big loss of power?

PS I could be wrong, but wasnt some of the 95's OBD?

 

thats what I thought but I tried again last night and all the CEL does is stay on just like it always does before I start it it may not have any codes stored because I had to jump it the last couple days
I have the jeep home now and im planning to go buy new ccv valves looks like those are dealer only... the hoses are clean and clear but the actual valve doesnt work so even if thats not the problem I need to fix it.
I may go pull the cap off and inspect that and the rotor this morning.... Im pretty sure there good because they were changed fairly recently....
symptoms were a little different yesterday it would back/miss fire on slow uphill sections before it could downshift as well as its "stutter" on the freeway
but on the ccv system there are two elbows coming out of the cover and the one up front is blowin smoke pretty bad into my air intake replacing that one wont do anything because its just a 90 degree elbow so how do I fix this blow by? i need to out my new air filter in but i dont want it to just get drenched in oil
thanks for all your help guys