325E Starts and stalls immediately, Tried everything

[Luxy30]

I have an interesting problem in my 1986 325E. It starts and dies almost instant sometimes runs a few seconds. I have searched every e30 forum out there. I have replaced a bunch of parts too including: fuel pump, filter, spark plugs, Ecu, distributor, rotor, FPR, cleaned maf contacts, checked for vacuum leaks with smoke tester. Pretty much everything that is common to go on those cars. Car only has 98k miles.

It's getting good fuel pressure and spark ( checked with spark tester). Could it be a relay that switches something off? Maybe timing? Any other suggestions for what to look for?

[dnguyen1963]

Check your CPS. Make sure you have an OEM BMW unit.

[Luxy30]

I have replaced the CPS. I believe it was an oem part. All the numbers are In spec to the manual too? Do you know of any other tests for the sensor?

[curtis_luu]

Have you done any work prior to it running this way?

[dnguyen1963]

Did you measure the distance from the CPS to the tooth wheel? It is supposed to be 1 +/- 0.3 mm. If it is off then the DME might lose the signal.

[Gtihodi]

Mine too

[Tyler_Prazzo]

I have a e30 too with the m20, its runs then dies, if you hold the key in the position to engage the starter it will stay running and act completely normal, but as soon as the key falls back to the run position the car dies, any clue to what this could be?

[tomstin]

What engine (E or I)? The E motors have two sensors on the bell housing, one is the reference sensor (once per revolution) the other is the engine speed sensor. The other thought is the fuel pump relay may be dropping on you.

[reelizmpro]

I used to have a 325e that would die whenever I let off the gas. Ended up being a large exhaust leak at the rear muffler. The pipe had completely separated from the muffler body.