This idle makes me want to blow my brains out

[NJ2.5rser]

This idle makes me want to blow my brains out

Did you try the tps sensor?


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[foundation982]

You may not want to spend the $100 on the smoke test but that, a check of the TPS, and a check of the rail fuel pressure are mandatory diagnostics.

Have checked TPS need to do a pressure test on fuel rail still.

[jlevie]

This is very true. I know I've been told this a couple times but the car is a heap of crap. I don't want to spend the $100 to just have a smoke test done. I live in the middle of nowhere and I'm not sure if any of the shops around here even have a smoke tester.

You may not want to spend the $100 on the smoke test but that, a check of the TPS, and a check of the rail fuel pressure are mandatory diagnostics.

[dnguyen1963]

you can make yourself a DIY smoke machine for about $25. Search here or Google it. It will not be good enough to find all the leaks, but it will find all the major ones.

[foundation982]

I know you've replaced a lot of the hoses and gaskets but you really need to smoke test it to rule out vacuum leaks.

This is very true. I know I've been told this a couple times but the car is a heap of crap. I don't want to spend the $100 to just have a smoke test done. I live in the middle of nowhere and I'm not sure if any of the shops around here even have a smoke tester.

[SlamedIAm]

I know you've replaced a lot of the hoses and gaskets but you really need to smoke test it to rule out vacuum leaks.

[foundation982]

I've had this car for about a year and have been non stop fighting the idle on it. I know it's an e28 but it is the 528e ETA engine
The idle seemed fine the whole winter right around 800 rpms but here in IL the entire winter was literally -10 to -40 outside that may have been what kept it down. Now that it's warming up its steadily risen to 1100rpm and just today it started sitting at 1400rpm and would sometimes begin to terrible idle surge going up and down very slowly.


I have been trying everything and cannot get it to steadily sit at 700-750rpms

Things I've checked/done
-All intake rubber hoses checked/replaced.
-Idle control module swapped in with a working one
-swapped in working ECU
-Rebuilt fuel injectors and O-rings
-Replaced Intake manifold gaskets and oil return O-rings
-Swapped in working ICV
-Tested TPS
-Replaced coolant temp sensors on thermostat housing
-Replaced O2 sensor
-swapped on a known working oil cap
-Replaced cap, rotor, wires.
https://www.youtube.com/watch?v=wR92kf_osk0

Sorry for the excessive revving obviously couldn't get it to do the slow idle surge on camera