99 trooper 3.5
I have been putting off posting til I had more info because I never felt like I had this pinned down.
Main issue:
Low power/hesitation
Idles great around 800. Revs/sounds fine in park.
However, from stop and a good amount of throttle it revs then it will shake/stutter and/or kick in.
If I accelerate very slowly it will switch gears fine. Otherwise it will go well over 3000rpm before switching. During that time Very low power.
If I take a corner, it downshifts, then I accelerate, it revs high without being in gear.
Codes:
Finally got one Today. P0300
I'm posting because I finally got something that might be helpful to diagnose this. After warmup it will go into closed loop as normal. Using my obd reader Ive been checking lots of parameters. LTFT is negative (-6 and - 12) at idle or driving without TB open. Driving and accelerating, it will work its way to less negative.
Today I was driving was monitoring the fuel status. When I'd accelerate quickly or take a corner (lack of power), the system would go into open loop/deceleration fuel cut. So it stops adding enough fuel. Which makes sense on loss of power... I read that in that state it goes by a "fuel map" in the computer.
So I'm not really sure what to do next. I've done a lot of things...but most were 2 years ago then it sat. The main thing I've noticed that might be an issue is I had replaced the compressor and most a/c parts. The a/c works great. However, the clutch will slowly rotate when not engaged. So I need to increase the gap. That couldn't cause a timing issue could it.
Timing is within spec (from service manual) while idle and Rev to 2500 in park. Fuel pressure is low for what the manual says. It's 38-40. Had a new fuel pump added two years ago before sitting.
Checked coils and plugs. Some oil in there brownish soot. Not bad. Gap a little large so adjust back.
Had the fuel rail out. Individually charged and cleaned each one with a nice spray pattern.
New fuel regulator. During idle if I pull the vacuum hose it's sucking and the engine fluctuates. Back on it stabilizes.
New evap canister. New evap purge solenoid. Solenoid continously clicks. Another one I had pulses continuously but no noise.
TB, IAC, MAF all cleaned. Fresh gas after empty. Filled up. I should change the oil... MAF had correct voltage and ground. New Air filter. Radiator and coolant fine. New fuel filter. (After sitting the line right before the fuel filter had deteriorated and leaked.)
Battery was dead but easily charged back up and hasn't been a problem since.
I currently have the center console out. I mention that because the power/winter mode wire isn't connected. If that matters.
Might be some other things but I'm leaning toward a fuel pressure issue, computer issue or something to do with the compressor and/or timing.
Thanks for any help. Scott
I have been putting off posting til I had more info because I never felt like I had this pinned down.
Main issue:
Low power/hesitation
Idles great around 800. Revs/sounds fine in park.
However, from stop and a good amount of throttle it revs then it will shake/stutter and/or kick in.
If I accelerate very slowly it will switch gears fine. Otherwise it will go well over 3000rpm before switching. During that time Very low power.
If I take a corner, it downshifts, then I accelerate, it revs high without being in gear.
Codes:
Finally got one Today. P0300
I'm posting because I finally got something that might be helpful to diagnose this. After warmup it will go into closed loop as normal. Using my obd reader Ive been checking lots of parameters. LTFT is negative (-6 and - 12) at idle or driving without TB open. Driving and accelerating, it will work its way to less negative.
Today I was driving was monitoring the fuel status. When I'd accelerate quickly or take a corner (lack of power), the system would go into open loop/deceleration fuel cut. So it stops adding enough fuel. Which makes sense on loss of power... I read that in that state it goes by a "fuel map" in the computer.
So I'm not really sure what to do next. I've done a lot of things...but most were 2 years ago then it sat. The main thing I've noticed that might be an issue is I had replaced the compressor and most a/c parts. The a/c works great. However, the clutch will slowly rotate when not engaged. So I need to increase the gap. That couldn't cause a timing issue could it.
Timing is within spec (from service manual) while idle and Rev to 2500 in park. Fuel pressure is low for what the manual says. It's 38-40. Had a new fuel pump added two years ago before sitting.
Checked coils and plugs. Some oil in there brownish soot. Not bad. Gap a little large so adjust back.
Had the fuel rail out. Individually charged and cleaned each one with a nice spray pattern.
New fuel regulator. During idle if I pull the vacuum hose it's sucking and the engine fluctuates. Back on it stabilizes.
New evap canister. New evap purge solenoid. Solenoid continously clicks. Another one I had pulses continuously but no noise.
TB, IAC, MAF all cleaned. Fresh gas after empty. Filled up. I should change the oil... MAF had correct voltage and ground. New Air filter. Radiator and coolant fine. New fuel filter. (After sitting the line right before the fuel filter had deteriorated and leaked.)
Battery was dead but easily charged back up and hasn't been a problem since.
I currently have the center console out. I mention that because the power/winter mode wire isn't connected. If that matters.
Might be some other things but I'm leaning toward a fuel pressure issue, computer issue or something to do with the compressor and/or timing.
Thanks for any help. Scott