New Addition to the stable... M30 questions too

[SnakeyesTx]

Well, if it weren't for my E34, and a lot of you guys, I probably wouldn't be in the boat I'm in now... just picked up my next pet project to drive while I work on the 540...



Better angle




It's an 87 535isA. It's got 187k on the still working odometer (I hear this is rare) and everything except the cruise control works.

Since the M30 is virtually unchanged from the end of the e28 to the beginning of the e34, I thought I'd pose this question to get possible solutions from different angles. The car runs smooth as silk as you're moving along, however it's a little bit hard to start, and the idle is kinda rough. As soon as you throttle it even in the slightest, it revs up perfectly smooth... it's only at idle where I have issues. Sometimes when you crank it over, it catches and stalls almost immediately if you don't have your foot on the pedal just slightly.

Did a bit of reading and it was suggested that maybe the TPS wasn't clocked over enough when the previous owner replaced it. The idle control valve appears to be new as well. Not really sure where to start tackling this. I changed the plugs this morning but they looked fine, as did the cap and the coil. I drove it 53 miles home from where I bought it and averaged 21.6 mpg.. not bad for an M30 from what I hear.

[SnakeyesTx]

Update : Hard starting fixed... TPS wasn't installed properly.. repositioned and that part is okay. Idle is still pretty rough however. Runs smooth as soon as you give it a hint of accelerator pedal pushing and drives just fine. Only no-throttle input gives rough idling. Still not sure where to start on this. Replaced all the vacuum lines and plugs. Cap looked good, coil is hot and wires are newish.

C'mon guys some of you with M30's have to have an idea somewhere? =/

[bubba966]

Any idea when the valves on it were last adjusted? Might want to do it if you don't know when it was last done. And if you do them yourself make sure the engine is dead cold when you do it.

[SnakeyesTx]

Yeah, I read about having to do this on M30's ... I'll take a crack at it this weekend and see how it goes. I wouldn't doubt if it was never done before.