HELP! Crank but No Start on a 91 325i, any suggestions?

[AlpinaE30]

So the car runs fine the day before, no surging or any wierd things while driving the car. Then the next day, it cranks but no start, so I started to diagnose the problem. First, I checked the fuel pump, applied 12v and it buzzes, so I think its good. I replaced the main relay and fuel pump relay with known good ones from a running car, still, no start. I checked fuse#11 and it is good, but when i check for 12v on fuse#11, no power. It should have power when the key is on, correct? so that means its not powering up the fuel pump. so i thought, well, since the relays are good, i think it might be a bad ecu. so i installed a known good ecu, still no start. any ideas?

thanks in advance.

ric

[Philo]

Wrong section.

But if it where in the correct section, I might advise you test the crank positioning sensor. :D

[delatlanta1281]

1.Have you actually checked to see if there is fuel pumping into the fuel rail? You should be able to jump the relay with the fuel line detached and see if it pumps.
2. gotta ask, do you have gas in your tank? How much?
3. Crank position sensor?
4. Check your connections on the other end of the CPS and make sure that didn't unplug.
Have you done any work on the car lately? Did one of your friends disconnect the ignition coil and leave the boot on to mess with you?
GL
Rich

[AlpinaE30]

Wrong section.

But if it where in the correct section, I might advise you test the crank positioning sensor. :D

sorry guys for posting in the wrong section...moderators, feel free to move it to the right section, thanks.

[kway]

Check the fusible link in the trunk.

[AlpinaE30]

Check the fusible link in the trunk.

Where in the trunk is the fusible link? What system is it part of? Fuel? Ignition system?

[StereoInstaller1]

It is shrinkwrapped in black, about 8" in front of the battery, on the secondary power cable.

That isn't it, BTW.

You said fuse 11 did or did not have voltage. I ask the same thing damn near every time: how did you test it?

[AlpinaE30]

Oh, its a vert, so battery is up front.

Tested fuse #11 by having the key to on position(warning light in dash on) and probing the test light on the fuse to see if it is getting voltage...nothing..i tried that same test on terminal 30 of the fuel pump relay and i do have battery voltage.

Im thinking it might be the crank sensor...is it a B**ch to get to?

[pharow]

I had the same thing happen to me yesterday. My car would crank and turn over, but it would not start. I tracked my problem down to a clogged fuel filter. I dont know if you have checked tht or not? It might help to take a look at it.

[Rascal2pt0]

Mine was a fuel pressure regulator. Pull the vacuum line off and smell the end. If it smells like gas replace your FPR.

[SlapDash]

Mine was a fuel injector harness connector. It was corroded, looked like someone left pennies in the rain. Cleaned it out, turned key, car started.

Good luck.

[AlpinaE30]

So i checked today, no spark! Im getting frustrated!

[jlevie]

No spark could be:

Bad CPS
Bad coil or no power to the coil
No power to the DME
Bad DME
Broken timing belt (rotor not turning)

The test for power at the fuel pump fuse is only valid when the engine is cranking over. The fuel pump relay is controlled by the DME and only engaged when the DME sees timing data from a rotating engine.

[AlpinaE30]

I'm getting intermittent spark..its driving me crazy...so I bought a spark tester from a local parts store...when i first turn the key to the on position (not cranking) i get a spark..then when i crank it, no spark..wtf?

i checked out the coil, and the only thing that kind of didn't check out was the resistance check of the primary (terminals 1 and 15, the book says it should be between 0.45-0.55 ohms, and i'm reading 0.7 ohms), i dont know if that would cause the intermittent spark/no spark condition.

i checked the fuel at the regulator, its spitting out fuel
i checked the crank sensor, resistance is within specs.
DME, main relay and fuel pump relay from a good known running car..

what else could be wrong? i'm getting frustrated!!!

[acefinland]

have u tried the fault code reader in the car. Not sure if u guys in the us have it but on european cars u just have to turn the key to the acc on the ingniton and push full throttle 5 times. Then the check control light should start indicating in a series of flashes. If its a broken sensor the "check" light will tell u.