E2i conversion on 1988 seta won’t idle right

E28 technical advice asked and given! Troubleshooting, modifications and more.
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Dman10311
Posts: 43
Joined: May 30, 2019 12:32 PM
Location: New Hampshire

E2i conversion on 1988 seta won’t idle right

Post by Dman10311 »

I originally posted on fb that my car after doing a e2i conversion that it refuses to idle properly on my 1988 seta 528e. I used all the proper 325i parts according to strictlyeta

What are the symptoms?
Car idles at around 800 but has a misfire almost every cycle, sounds like a rotary almost or a lopping cam

When revved cold it wants to die out (dips to 500rpm before recovering)

When warm it still misfires and sounds bad at idle but doesn’t drop below idle when revved

Drives perfectly fine, has zero misfire when driving and wot

What I’ve done to try to remedy the issue.

Replaced Fuel Pressure Regulator with new pier berg unit

Replaced fuel injectors with brand new Bosch 0280156346

Replaced blue temp sensor that goes to dme

Replaced Distributor, rotor, ignition coils, spark plugs with all brand new oem parts minus the wires are brand new ngk wires (whole ignition system is new)

Smoked tested the entire system and found one leak at the throttle body (fixed with a different tb) and one leak in the cabin that comes from the intake manifold and goes to some unit by the clutch pedal (what is the purpose of this?) (now is completely leak free)

Replaced tps sensor with a facet unit to see if that was the issue and no difference was made in idl

Tested fuel pressure and that turned out to be fine

Tried a 173 dme and that made no difference to my 524 dme

I’ve tried multiple afm’s and icv’s and zero difference was made

Compression tested motor (two cylinders were at 135 while the other 4 were at either 145 or 150) all within 10%

Tried ngk coppers over the recommended Bosch units and no difference

New Bosch o2 sensor

The 885 head is rebuilt minus the original 885 cam and was decked within spec and then compensated with a thicker head gasket to match oem spacing and valves are properly adjusted before installing

I’m running out of money and ideas so if anyone has anything to add that I can do please let me know.
turbodan
Posts: 9153
Joined: Jan 09, 2007 10:19 PM

Re: E2i conversion on 1988 seta won’t idle right

Post by turbodan »

How do the plugs look? Whichever cylinder is misfiring, if it's just one, should be loaded up with deposits and visibly fouled.
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