washed engine
Thread Starter
Intermediate
Joined: Jan 2005
Posts: 35
Likes: 0
From: Fort Lauderdale Florida
washed engine
I washed my engine and everything was good that day but next day idle went up to 1700. When I unplugged the TPS it went back down but then readjusted itself to 1700. Where could I have gotten water that might cause this?
Burning Brakes
Joined: May 1999
Posts: 760
Likes: 1
From: Greenwich, CT
Suggest putting a scanner on the ALDL port. There are only about 3 signals coming from the engine bay
that affect idle RPM:
1. If the CTS reading is -40 at start-up, you've open-circuited the CTS thermocouple. Repair or replace.
2. If the 5-wire(?) connector at the distrib is hosed, ECM will (perhaps) see an erroneous RPM signal.
Replace the wiring pigtail.
3. If the IAC motor or connector is hosed (or if you created an intake vacuum leak) the ECM will be unable to
maintain the idle speed set-point. That will be apparent from the ALDL datastream.
HTH
that affect idle RPM:
1. If the CTS reading is -40 at start-up, you've open-circuited the CTS thermocouple. Repair or replace.
2. If the 5-wire(?) connector at the distrib is hosed, ECM will (perhaps) see an erroneous RPM signal.
Replace the wiring pigtail.
3. If the IAC motor or connector is hosed (or if you created an intake vacuum leak) the ECM will be unable to
maintain the idle speed set-point. That will be apparent from the ALDL datastream.
HTH
