e34 issues...

[SilentJon]

'92 525i, m50, auto, 231k
car runs great, when it wants to. drives nice when it wants to, minus the rear shocks being dead.
it has a rough idle sometimes, other times is smooth as glass, then it'll fall on its face right off idle, or miss terribly above 3k...
and again, when it wants to, it runs perfectly
no intake leaks, tps and maf test good, dont know about the coils, but i do know that 3 are original, and the other 3 are a random selection of junkyard coils. no codes. check engine light came on, and now it throws a code 1221. o2 sensor
just got this car 3 days ago

the trans doesnt know what it's doing either. it works, then it doesnt, then it works, then it throws trans program in my face, then it doesnt work worth shit, then it works perfectly fine, and then doesnt work again.

oh, and it snapped one of the bolts on the diff mount bracket, left side, the one that goes through the bushing. sounds wonderful when the inner joint is sitting on the subframe! /sarcasm
i'm fixing that today

got the car knowing that it needed some work, but it's becoming a bit of a pain. it's probably sitting in the driveway laughing at me right now lol

help? im new to the m50, and the electronically controlled trans.

[be34st]

Originally Posted by SilentJon

'92 525i, m50, auto, 231k
car runs great, when it wants to. drives nice when it wants to, minus the rear shocks being dead.
it has a rough idle sometimes, other times is smooth as glass, then it'll fall on its face right off idle, or miss terribly above 3k...
and again, when it wants to, it runs perfectly
no intake leaks, tps and maf test good, dont know about the coils, but i do know that 3 are original, and the other 3 are a random selection of junkyard coils. no codes. check engine light came on, and now it throws a code 1221. o2 sensor
just got this car 3 days ago

the trans doesnt know what it's doing either. it works, then it doesnt, then it works, then it throws trans program in my face, then it doesnt work worth shit, then it works perfectly fine, and then doesnt work again.

oh, and it snapped one of the bolts on the diff mount bracket, left side, the one that goes through the bushing. sounds wonderful when the inner joint is sitting on the subframe! /sarcasm
i'm fixing that today

got the car knowing that it needed some work, but it's becoming a bit of a pain. it's probably sitting in the driveway laughing at me right now lol

help? im new to the m50, and the electronically controlled trans.

Check your distributor cap/rotor, and sparkplug wires. If they are old they likely need to be replaced and could be the cause of a rough idle. Also check your fuel pump/filter about the bogging.

I've also read that on M50's the AIT (air intake temperature sensor) can cause bogging. "It's a variable resister type sensor like a coolant temp sensor, it measures the temperature of the incoming air charge to tell the DME so that it can advance/retard timing and adjust fuel trim settings" I imagine this only applies to the M50TU, but im not sure. Maybe try replacing that.

I dont know too much about the M50 but maybe that will give you somewhere to start. Good Luck!

For your trans program you may be able to find some answers here.

Trans Program

[SilentJon]

Originally Posted by be34st

Check your distributor cap/rotor, and sparkplug wires. If they are old they likely need to be replaced and could be the cause of a rough idle. Also check your fuel pump/filter about the bogging.

I've also read that on M50's the AIT (air intake temperature sensor) can cause bogging. "It's a variable resister type sensor like a coolant temp sensor, it measures the temperature of the incoming air charge to tell the DME so that it can advance/retard timing and adjust fuel trim settings" I imagine this only applies to the M50TU, but im not sure. Maybe try replacing that.

I dont know too much about the M50 but maybe that will give you somewhere to start. Good Luck!

For your trans program you may be able to find some answers here.

Trans Program

no distributor on an m50, it's coil over plug :P
im ordering a new intake boot, thermostat and o2 sensor today. i think the previous owner's duct tape idea needs to go, and might be a majority of my problem

i went to the junkyard yesterday and got a perfect set of tails for it, 2 full obc's, an ashtray, and some relays and fuses, just because they fit in my pockets....
and the differential bracket, it can be driven safely without the cv grinding into the subframe now

[MeanM50]

First, start by confirming you have good coils.

Next, verify that you have no vac leaks.

Also, make sure you are getting good fuel...fuel filter/pump diagnosis....

Finally, report back and we will go from there.

Good luck

[SilentJon]

vacuum leaks fixed, coils good, fuel pressure good. e34=pissed
yesterday it wouldnt move, today it's fine. im cornfuzzled