no spark no fuel

[slupregime]

ok guys my 90 535i just started not starting when it wants to i had it towed to my mechanic yesterday and he got it started right away... i get it back for 2 hrs and then the same again no start.. he got it started but not for long...so a couple questions what does the cps suppost to read...he said he got a reading but i forgot what it was and he got a pulse reading from it when he cranked it over but no spark..so if it is ok could it be the main relay or the ecu?

thanks in advance

nick

[winfred]

theres 3 tests for a cps, pulse, ohm's and current, they can pass 2 out of 3 and be bad, i can't remember exactly what that one reads as resistance 540 or 900 something, pulse is not that important and takes a scope to read, current, should make at least 1 volt AC at cranking speed, generally if the main relay is working the idle control valve will buzz slightly to the touch with the key on

[outomoneyracer]

ok guys my 90 535i just started not starting when it wants to i had it towed to my mechanic yesterday and he got it started right away... i get it back for 2 hrs and then the same again no start.. he got it started but not for long...so a couple questions what does the cps suppost to read...he said he got a reading but i forgot what it was and he got a pulse reading from it when he cranked it over but no spark..so if it is ok could it be the main relay or the ecu?

thanks in advance

nick
When my e34 had no spark no fuel it was main relay. $25 at the dealer; would be the first thing I would try if I was you.

[Tiger]

How did you make out on the M20 that you asked us? Was it the CPS or the fusible link? or main relay?

[slupregime]

the little motor doesnt run but started once out of 50 trys maybee but the motor by the intake wasnt running when it did start up

[slupregime]

i ordered the relays.. fuel and the main where bad ..running the car on jumper wires till they come in