TPS voltage problem

[cre]

Originally Posted by 1989toyotasupraandpickup

its running rich on idle. before the i replaced the manifold gaskets at idle the car would run at 14.7 on the afr gauge. now that i put it back together i find that the car idles at around 12.5 or so. no codes that i have found but the check engine light will not light up if there is a code. it does turn on when i turn the key to the on position indicating that the light works. i have to jumper the terminals in the diag box to find if there are codes. really weird. my truck is the same way. but i think i may have found the problem. it may have been a broken signal wire to the oxygen sensor just off the down pipe. its a shielded wire. i fixed it and put a new connector on and decided to replace the main front crank seal seams i have it all ripped apart and the old one was dry rotted. i will have it running by tomorrow hopefully.

The AFR will be around 13, maybe a little richer, when the ECU is operating in open loop (cold starts, bad ECU temp sensor, bad TPS signal, no OX signal, etc).