Both CPS? at the same time?

[bmwman91]

Totally out there with this one...

Could the crank have broken up front so that the timing assembly is not being driven? If the Woodruff key goes, that could happen. Run the starter and have someone look in the oil filler hole to see if the chain is being driven. You could try with the valve cover off but that would make a big mess.

Since the timing was checked and was good, this is probably totally unlikely. It sounds more and more like some sort of ignition gremlin.

[sfinsf]

Totally out there with this one...

Could the crank have broken up front so that the timing assembly is not being driven? If the Woodruff key goes, that could happen. Run the starter and have someone look in the oil filler hole to see if the chain is being driven. You could try with the valve cover off but that would make a big mess.

Since the timing was checked and was good, this is probably totally unlikely. It sounds more and more like some sort of ignition gremlin.

seems unlikely that a mechanical is causing this, however it did fail under acceleration. But every test on the system has been positive...
I agree that the electrical system has some sort of an issue. Everything mechanical is testing out.

Any suggestions on finding the gremlin?

[enildeR]

just sharing my experience. a few years ago, I had a similar problem. I tried troubleshooting it for a weekend, but I didn't have time to finish. took it to a shop, and it even confuzzled him. he did eventually find out the problem. it was the main crank pully. if you look at it, the rubber vibration dampener is what holds the timing marks for the hall effect pickup for firing the injectors and iginition. the rubber had seperated and the "timing disc" had slipped, resulting in timing being completely off.

I'd go and see if the "timing disc" can be moved by hand, or if there is any play what-so-ever. also, he had to replace the sensor, as he said the disc breaking free smashed into the sensor. he even showed me the old pully. it was completely separated from the main pully. it blew me away. I just couldn't figure out how BMW engineers thought it would be a good idea. I was pissed and happy at the same time. I had my BMW back, but I was completely pissed off that BMW engineers could do something so stupid.

[R. Orona]

If it's not the relay it's likely the CPS.  Without the crank sensor signal the computer won't turn on the relay, so no fuel pump.

On the crank sensor wire, pins 1 & 2 need to be about 640 ohms, pins 2 & 3 and 1 & 3 should be very high, like 300K ohms or so.  I looked at your earlier post...you did test the sensor, right?  Not the harness heading back to the computer, right?  If so, don't do that.  Doing a resistance or continuity test on the harness can damage the computer.

I'd advise getting a cheap multimeter at Radio Shack, Sears or Harbor Freight.  They're self-calibrating, do many tests, and are very reasonable.  I bought a few of the $4.99 HF units (along with some of those cheap LED flashlights) just to have in the cars.  You never know when you'll need one!

Yes that would help in many cases. There is not harness is going to head on you computer for sure..