Hey everyone my 87 ta 305tpi 700r4 has been idleing at 7-8 hundred rpm in drive and when i shift to park it goes to 1500 rpm, if i rev it while in park it goes back to normal. the iac was just cleaned and adjusted to 550 as well as the tps voltage. any ideas what this could be.thanx

 

Before you cleaned and adjusted IAC and set the TPS how was it running? Maybe check the fast idle screw, make sure that it wasn't screwed in to correct the problem with your IAC and TPS. Check your ecm to see if it is storing any codes, clear them if neccesary.

 

The idle screw in the throttle body is set okay, and the only code I ever tripped was (43)the knock sensor from running 93octane.Once it gets hot for awhile @ 40 minutes of driving it seems to go back down to 550 in drive. I just dont get why at a stop light itll be idleing at 800 then i throw it to park goes to 1500 and when i rev it once to 2200 or so the idle goes back to 550.thanx