It’s me Rene again…
I’ve got a question for you (hopefully you can answer this).
1990 BMW 325i e30 (stock)
Only addition is a MAF sensor instead of a AFM.
My question is this…
Ever since I installed the MAF and removed the AFM, I’ve been having idle issues.
When I start the car it idles fine. I take it out for a drive 30 minutes or so.
I get home and let the car sit at idle for a few minutes and the idles starts to go up (as high as 1500rpm)
Turn the car off, start it again, and the idle is still high.
Not until the car cools down and I start it again does the idle go back to normal.
And then again if I let it just sit at idle it starts to go up.
Coolant Temp Sensor???
Throttle plate (butterfly) adjustment???
If it is the throttle plate what should the setting be? (How open should it be at rest/closed position?)
I have checked the TPS and it is sending a closed signal to the Computer when the plate is at rest. But that doesn’t mean that plate/butterfly is resting where it should be.
I have checked for vacuum leaks, as of today, I have not found any.
I’m really confused about this, and hopefully you can help.
Hi Mr. Acosta, I will need a little more info. What computer system are you using after the MAP conversion? Do you have the ability to datalog? If so I would like to see the logs please. A vacuum leak will not be the issue as the MAP reads total air inside of the intake and would take the leak into account. The E30 TPS is not a sensor but 2 switches, there is an idle and wide open throttle. Make sure that the idle switch is reading ok when the issue is occurring.
Do you have a manual for the car? If so, in the manual there will be a conversion table for the coolant temperature sensor, it will convert ohms to temperature, use it to check the sensor. Let me know what you find with them please.