C4llyT

E36 M3, but possibly a generic fault/cause etc..

Brother has my old M3, it broke down and wouldn't start, just span without a hint of firing.
RAC chap sprayed easystart in and ran for few seconds, and diagnosed fuel pump.
Brother changed relay, checked fuses etc etc nothing worked, never heard pump go.
Just had battery off for a bit, back on, and it fires up and runs every time without fault.

Glad it's running, but nice to know wtf's going on!
Thinking ECU or immobilisor fault, but don't know how or why.
Any ideas?!

skinnybalboa

hey had this fault recently with my e36 3 series not an m3 tho, but it could be worth taking out the cam and crankshaft sensors and making sure there clean as mine was dirty and would just cut out but if you left it a while it would run perfect for a few weeks.

C4llyT

Both the tdc and the cam sensors are new. Has been through a couple tdc sensors but they just cause rough running.
I know on other cars crank sensor can prevent starting, but think that cuts spark rather than fuel?
Behaving like an old cavalier, take battery off for a minute and all is well for a while

RichieST

iTrader: (2)

Happened to an old car of mine, it would start first time on the button, then it would go for a few days without even trying to start.

Turned out the fuel pump was on its way out! Can you hear it prime when u turn the ignition on?

Mike C

iTrader: (1)

I had the same thing with my E36 318is

Wouldn't start, plugged in a diagnostic machine, showed no faults, then once that had done, it fired up first time and the issue never returned

C4llyT

Mate (specialist) said could have been sticky fuel pump.

Could be on way out, brother never heard it prime for the whole week he was trying to fix it!

What I really want to get to bottom of, is what the immobilisor cuts - fuel or spark?!

Car would never start if key left in acc pos 2 for couple seconds or more, just spin and spin and spin, yet always on the button if turned quickly.
Also, on diagnostics you can see the EWS (immobilisor) randomly go connected/dis-connected, and never got to bottom of this, but never had a problem either.

Looking like pump, be nice to know what is cut when immobilised though.