Aloha Everyone,
I have a 91 TBI chevy suburban with a 4l80e that seems to idle high in park and neutral (no tachometer). When you shift it into Drive the idle drops a little and wants to take off, I need to hold the brake. When I let go the brake it will go to about 5-10 miles on flat ground with out pressing the gas.
Background information.
It used to sputter on start up and want to die if you started it up and tried to drive off right away. If you let it sit and warm up in park it would be okay. No idle issues back then. Off and on problem for about a year.
About a month ago it seemed like the transmission was slipping on take off. I would have to press the gas and then it would engage real sharp/ a big jerk and then it would go. When I stopped it would some times have a big pause and then a big jerk before it would shift down at the stop lights and I could let my foot of the gas and it would idle. This didn't happen all the time though.
All of these issues have gone away and have been replaced with the high idle and not wanting to shift down when stopped and wanting to take off in drive.
Is this an idle issue or transmission problem?
I have replaced the IAC and the TCS.
I have checked:
- Distributor magnet doesn't look like there are any cracks.
- Throttle body shaft play is minimum. It does wiggle but just barely.
- Can't find any vacuum leaks.
- Disconnected EGR and idle stays high
- Disconnected TPS and idle stays high and shifting goes harsh.
- Disconnected battery for 10 minutes to see if things would reset. Nothing
- No check engine code (checked before and after battery disconnect). I get code 12.
Injectors look like they are spraying continuously and are not pulsing in park but I could be seeing things. Could the injectors be dirty?
Any help would be appreciated. Mahalo
I have a 91 TBI chevy suburban with a 4l80e that seems to idle high in park and neutral (no tachometer). When you shift it into Drive the idle drops a little and wants to take off, I need to hold the brake. When I let go the brake it will go to about 5-10 miles on flat ground with out pressing the gas.
Background information.
It used to sputter on start up and want to die if you started it up and tried to drive off right away. If you let it sit and warm up in park it would be okay. No idle issues back then. Off and on problem for about a year.
About a month ago it seemed like the transmission was slipping on take off. I would have to press the gas and then it would engage real sharp/ a big jerk and then it would go. When I stopped it would some times have a big pause and then a big jerk before it would shift down at the stop lights and I could let my foot of the gas and it would idle. This didn't happen all the time though.
All of these issues have gone away and have been replaced with the high idle and not wanting to shift down when stopped and wanting to take off in drive.
Is this an idle issue or transmission problem?
I have replaced the IAC and the TCS.
I have checked:
- Distributor magnet doesn't look like there are any cracks.
- Throttle body shaft play is minimum. It does wiggle but just barely.
- Can't find any vacuum leaks.
- Disconnected EGR and idle stays high
- Disconnected TPS and idle stays high and shifting goes harsh.
- Disconnected battery for 10 minutes to see if things would reset. Nothing
- No check engine code (checked before and after battery disconnect). I get code 12.
Injectors look like they are spraying continuously and are not pulsing in park but I could be seeing things. Could the injectors be dirty?
Any help would be appreciated. Mahalo
