Rough idle When warm

[waos]

Car idles fine until it starts to warm up and then the idle becomes very rough almost to the point of stalling. Stomp test workers before starting the car but after I shut it off when the idle becomes rough, the stomp test no longer works. Could this be a connector or ECU issue with the TPS?

Things replaced
-o2 sensor --- Bosch 15718

-TPS sensor --pelican parts

-valves adjusted

-spark plugs - NGK ZGR5A

-vac lines and intake boot

-CTS -- White 2 pin from FCP

-C191 Connector ---Custom Deutsch connectors

Before idle change // Cold

https://youtu.be/ptaLsB2fI_c

After // temp gauge 1 line above cold

https://youtu.be/6TIp52RnetM

1989 BMW 325i 2.5L

[e30davie]

did you calibrate the TPS properly? it spins on its mounting screws.

[waos]

did you calibrate the TPS properly? it spins on its mounting screws.

Yes, reads 0 resistance at idle and wide open throttle, checked the signal going to ECU too, and it's the same.

Cleaned and checked the resistance of ICV and all is good. CTS resistance is good and matches what is being sent to ECU.

[e30davie]

Does adjusting the throttle stop to let a bit more air in help?

[waos]

Does adjusting the throttle stop to let a bit more air in help?

Nope, still choppy.

[It's Soda Not Pop]

Here is a stupid question have you unplugged the battery and reset the DME?

I had issues with mine idling weird. Some of it was due to a ICV (it wasn't an oem Bosch). I adjusted everything as you did. But after I reset the DME it worked great.

[dnguyen1963]

Do a smoke test when the car is warm. I bet you'll find vacuum leaks.

[moatilliatta]

Is the check engine light on?

[waos]

Replaced the FPR, fuel filter, and O2 sensor heater relay, it seems to be fixed.

[It's Soda Not Pop]

Replaced the FPR, fuel filter, and O2 sensor heater relay, it seems to be fixed.

Yeah I had a main relay go out on me. If you can replace everything that you know you haven't done or looks 30+ years old.