Hesitating

[LWB SCOTTY]

93 YJ that is hesitating once it hits 3000 rpm. If the clutch is in or its out of gear it revs past 3000 but when driven it lacks power and sputters around 3K. The starter is slowly dying and the exhaust is shot. It only has 85,000 original km's also. Has anyone had this similar problem or have any ideas for me to think about? Any help would be greatly appreciated. There is a nasty rattle underneath but I'm pretty sure it is coming from the rotten exhaust and not from the tranny or T-case. It will hold speed limit on highway but takes a bit of effort to get there.

[yjcanibul]

is your check eng light working, any codes ?

http://www.jeephorizons.com/tech/yj_codes.html

code 24 and others may be related to hesitating, the throttle sensor (tps) tells computer the pedal is down, advance timing and dump fuel ( learned abit about all those mpi sensors from a recent jp mag article );

even though mileage is low has it seen any maintenance lately ( plugs etc )

not sure how long you've had this jeep so give us an idea what its been doing lately ?

just another quick thought if this unit is new to you:

I run the MPI off a 95 yj -  it runs smoooooth / awesome on premium - anything else it takes spells and runs like my old carb setup ( crap! )


just some thoughts ...

[BlackYJ]

I had a similar problem, but the opposite.  Mine sputtered below about 3000 rpm and then was fine with higher rpms.  Turned out to be a worn cap and rotor.  I would suggest taking a look and replacing as necessary the plugs, wires, cap, rotor and fuel filter.

[Bnine]

93 YJ that is hesitating once it hits 3000 rpm. If the clutch is in or its out of gear it revs past 3000 but when driven it lacks power and sputters around 3K. The starter is slowly dying and the exhaust is shot. It only has 85,000 original km's also. Has anyone had this similar problem or have any ideas for me to think about? Any help would be greatly appreciated. There is a nasty rattle underneath but I'm pretty sure it is coming from the rotten exhaust and not from the tranny or T-case. It will hold speed limit on highway but takes a bit of effort to get there.

Bang around the cat converter and see if these's crap floating around in there.

By all the crappy exhaust descriptions, it sounds like your cat might be done.

[HIWYH8R]

That rattle in the exhaust is most likely the stuff inside the cat converter falling apart and plugging the outlet so the exhaust can't exit. Running out of power and rpm's not going above 2-3000 is a typical symptom of a plugged exhaust. Try to disconnect the exhaust pipe at the manifold and take it for a (loud) rip. You'll know right away if that was the problem.

[LWB SCOTTY]

93 YJ that is hesitating once it hits 3000 rpm. If the clutch is in or its out of gear it revs past 3000 but when driven it lacks power and sputters around 3K. The starter is slowly dying and the exhaust is shot. It only has 85,000 original km's also. Has anyone had this similar problem or have any ideas for me to think about? Any help would be greatly appreciated. There is a nasty rattle underneath but I'm pretty sure it is coming from the rotten exhaust and not from the tranny or T-case. It will hold speed limit on highway but takes a bit of effort to get there.

Bang around the cat converter and see if these's crap floating around in there.

By all the crappy exhaust descriptions, it sounds like your cat might be done.

It was the cat. It was all busted up. I replaced it and now everything is working fine. Thnks for all the help.

[Bnine]

Cool, good to hear.