i have an 87 t-bird lx. have replaced most of the sensors and relays, new belts and hoses, cleaned the throttle body. disconnected the battery to allow computer to reset and set idle to factory spec with computer disconnected.
when i reconnect the computer and restart car the idle jumps up to about
any ideas
walt peifer opined in news:pkmRd.56478$ snipped-for-privacy@tornado.tampabay.rr.com:
This will require some extensive troubleshooting.
The symptoms SEEM to rule out a straight vacuum leak/disconnect... assuming your heater system is operative.
So you need to look for an emissions systems fault, such as the EGR tube broken or vapor recovery.
Otherwise, it is common for bad wiring grounds in Fox platforms to cause this. Disc the ISC harness. and see if there is a change
Make sure the ground at the ECM (passenger kick panel) is good. Also that the block to firewall ground is good
You didn't mention replacing or cleaning the IAC, you might want to take a look at that. Also verify the TPS is in good working order and below .99v at idle. The set screw on the TB is not to set the idle, there is no idle set for an EEC-IV controlled engine. The set screw is a stop for the throttle plate and is set open to a certain gap. With the IAC disconnected the engine should not idle, the rpm's should drop and the engine should die in a few seconds.
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