I posted this over in the Engine and Drivetrain section but haven't gotten any responses yet. I figured that this forum gets a lot more traffic
I've got a 2002 TJ with a 4.0 and NV3550
just as background info, I replaced the stock cam with a COMP 68-201-4 (260H) to fix a bunch of noisy lifters, but the cam swap was months ago and the problem just started.
mechanical fan replaced with a taurus E-fan.
otherwise the engine is stock
BEFORE ANYONE SAYS TO CLEAN THE IAC VALVE,
Its been cleaned and the problem persists.
THE PROBLEM
Recently it started revving up at idle once it warms up.
When cold, it'll idle perfectly content at 750 or so.
When rolling to a stop in neutral (or clutch in) itll idle at 900 or so (cold) as soon as i stop completely, it drops to 750
It has done this ever since i got it two years ago, and seems to be normal behavior
Once the temp gage gets to 200 or so, it starts acting weird.
at first, the idle will bounce between ~700 and ~1000 pretty regularly
when rolling to a stop, it holds about 1100 or so, then drops to 700 when stopped, then starts bouncing
after a while of this, the bouncing starts creeping up towards 1000-1100 rpm, especially after driving.
finally, after 5 minutes or so the jeep idles perfectly smooth at 1100 or so and doesn't really drop below that.
Restarting the jeep (even just turning it off for a second) fixes the problem for about 3-5 minutes
I haven't noticed any loss of power, and the engine revs perfectly fine to redline.
It DOES NOT SURGE on the highway or around town AT ALL
once on the pedal, everything is 100% fine.
------
I first cleaned the IAC and although it was slightly sooty, it wasn't terrible.
No fix.
Changed the plugs
No fix
Re-Gapped plugs slightly tighter (0.030) to test for weak coils
No fix
replaced all the vacuum connectors that went between the manifold and charcoal canister/Leak detection pump.
No fix
Disconnected IAC connector
Idle still bounces around, even with the valve connector unplugged
TPS was replaced with the cam swap since i broke the factory one taking it off
any ideas?
the bouncing idle is driving me crazy
I've got a 2002 TJ with a 4.0 and NV3550
just as background info, I replaced the stock cam with a COMP 68-201-4 (260H) to fix a bunch of noisy lifters, but the cam swap was months ago and the problem just started.
mechanical fan replaced with a taurus E-fan.
otherwise the engine is stock
BEFORE ANYONE SAYS TO CLEAN THE IAC VALVE,
Its been cleaned and the problem persists.
THE PROBLEM
Recently it started revving up at idle once it warms up.
When cold, it'll idle perfectly content at 750 or so.
When rolling to a stop in neutral (or clutch in) itll idle at 900 or so (cold) as soon as i stop completely, it drops to 750
It has done this ever since i got it two years ago, and seems to be normal behavior
Once the temp gage gets to 200 or so, it starts acting weird.
at first, the idle will bounce between ~700 and ~1000 pretty regularly
when rolling to a stop, it holds about 1100 or so, then drops to 700 when stopped, then starts bouncing
after a while of this, the bouncing starts creeping up towards 1000-1100 rpm, especially after driving.
finally, after 5 minutes or so the jeep idles perfectly smooth at 1100 or so and doesn't really drop below that.
Restarting the jeep (even just turning it off for a second) fixes the problem for about 3-5 minutes
I haven't noticed any loss of power, and the engine revs perfectly fine to redline.
It DOES NOT SURGE on the highway or around town AT ALL
once on the pedal, everything is 100% fine.
------
I first cleaned the IAC and although it was slightly sooty, it wasn't terrible.
No fix.
Changed the plugs
No fix
Re-Gapped plugs slightly tighter (0.030) to test for weak coils
No fix
replaced all the vacuum connectors that went between the manifold and charcoal canister/Leak detection pump.
No fix
Disconnected IAC connector
Idle still bounces around, even with the valve connector unplugged
TPS was replaced with the cam swap since i broke the factory one taking it off
any ideas?
the bouncing idle is driving me crazy
0 commentaires:
Enregistrer un commentaire