1999 BMW Z3 Crank but no start !!!

Dear BMW fellows,

I have a 1999 BMW Z3 2.3 with the 2.5L M52 engine. The other day I went dinner with the wife and the car drove fine, but after dinner the car would not start. AAA towed it home and since I have been trying to diagnose/fix it. These are the test I have ran:

* The car cranks but does not start
* Fuses and relays seem to test OK
* Just replaced the fuel pump, fuel pressure as measure in the fuel injectors rail is about 51 PSI, just like the Bentley indicates
* When I spray starting fluid on the air filter box, the car wants to start it even runs rough for a second, so I assume I have spark. The ignition coils get voltage and the resistance on them seems correct according to Bentley.

I do not have any alarm system that I am aware of.

The only thing out of place is that I am getting voltage at the DME main relay but no ground (i.e I do not get continuity from the DME main relay socket 4 and ground). The Bentley manual recommends checking the cable from the relay to the ECM, I will probably take the DME/ECM apart tomorrow.

The previous owners of this vehicle did not take care of it like I would have liked them to. The seller mentioned after I bough the car that the electric on these cars is finicky which made me think that he had had some electric issues with the car.

The DME metallic case seems to be missing a screw/bolt at least on one of the corners for what I can see just by looking at it while on the car.

I am not sure what else to do or try, thanks in advance for your help!

Any faults stored by the DME? If main relay is not grounding DME is faulty considering that all inputs to DME are ok and wiring harness is not damage. Check ignition coils and injector resistance before ecu r/r. I think 1999 have MS41.1 DME'S you can't installed used DME as they get married to EWS once they are flashed and sync to EWS

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not clear. did you replace fuel pump before or after no start ? check for codes,check for crank shaft /camshaft signals to ecm. disconnect MAF sensor and try. put a noid [tester] on injector plug and look for pulse. it would seem you have spark but no fuel. if this all came about after pump replacement go back over your work and look for something amiss

Originally Posted by wifesauto

check for codes,check for crank shaft /camshaft signals to ecm. disconnect MAF sensor and try. put a noid [tester] on injector plug and look for pulse.

If it tries to start when sprayed, probably not getting injector pulse. Look at the tach while cranking to see if it moves. If not, probably crankshaft position sensor. May be inexpensive enough to try. If you do not have anything to pull codes and/or monitor data, then recommend taking to shop. Also try the MAF sensor as recommended.

Originally Posted by MINI+BMWtek

Any faults stored by the DME? If main relay is not grounding DME is faulty considering that all inputs to DME are ok and wiring harness is not damage. Check ignition coils and injector resistance before ecu r/r. I think 1999 have MS41.1 DME'S you can't installed used DME as they get married to EWS once they are flashed and sync to EWS

The codes I got using a OBD II tester are: P1188, P1428, P1421, P1189 and P1250. All but the P1250 have been there for a while. After the crank but no start situation I reset the codes and they have not came back.

I believe I have the Siemens MS42.1 DME, same problem as you mention above, I hope it is not bad.

Originally Posted by wifesauto

not clear. did you replace fuel pump before or after no start ? check for codes,check for crank shaft /camshaft signals to ecm. disconnect MAF sensor and try. put a noid [tester] on injector plug and look for pulse. it would seem you have spark but no fuel. if this all came about after pump replacement go back over your work and look for something amiss

The no start happen and the trying to bring the car back to life I replaced the fuel pump. It did not fix the situation but the fuel pump that was on the car, was not the proper BMW replacement it was taller than the stock, probably taken from another car.

I disconnected the MAF sensor and nothing happen, the car did not start.

I will get a noid tester or I will have someone crank while I listen for pulse on the injectors.

Originally Posted by brock5ga

If it tries to start when sprayed, probably not getting injector pulse. Look at the tach while cranking to see if it moves. If not, probably crankshaft position sensor. May be inexpensive enough to try. If you do not have anything to pull codes and/or monitor data, then recommend taking to shop. Also try the MAF sensor as recommended.

The tachometer does not move while cranking. Does this mean that the crankshaft position sensor is bad? Is there a way to test before replacement?

Another thing I noticed when I first removed the engine covers is that the ignition coil closest to the front of the car was missing a bolt and the other bolt, the one that holds the ground cable was loose and about to fall. Probably not related but, I have replaced the bolts and made sure all the other bolts and ignition coils are secure and working.

Is the ground cable on the RH/FR shock tower tight?

There is another ground in the trunk (behind LH felt trim panel) that also is related to a no start__though you did say you were getting fuel pressure at the rail...

Originally Posted by Randy Forbes

Is the ground cable on the RH/FR shock tower tight?

There is another ground in the trunk (behind LH felt trim panel) that also is related to a no start__though you did say you were getting fuel pressure at the rail...

They are tight Randy, Thanks!

I just replaced the crankshaft position sensor and the car is cranking but still not starting, not even trying to start. Any suggestions will be greatly appreciated.

Century BMW @ 8:00 AM.

I have a similar situation with my Z3(S52 transplant) but mine runs most of the time but usually in the A.M. or after it's set for a while it will spin over and over and over and over and I have to cycle the switch a bunch of times and then it starts and runs perfect. I am wondering if we have the same failure only yours is totally failed and mine is going out. I hate little things like this

Originally Posted by jwrape

I have a similar situation with my Z3(S52 transplant) but mine runs most of the time but usually in the A.M. or after it's set for a while it will spin over and over and over and over and I have to cycle the switch a bunch of times and then it starts and runs perfect. I am wondering if we have the same failure only yours is totally failed and mine is going out. I hate little things like this

Interesting, so you crank for a long time and it ends up starting up? On mine the injectors are not pulsating, my next steps will be to replace relays and see if the computer is sending the right signals. Once I figure out what the problem with the car is I will publish it here for future reference.

Yea, mine will start after many on off cycles of the key.

I am readying now that it could be due to a bad check valve in my fuel pump. A $20 check valve might help me.
seen in this thread.
http://www.bimmerfest.com/forums/sho...1&goto=newpost

I though I posted the solution of my problem a few months ago. Anyways, the problem ended up being a faulty receiver antenna ring around the key lock cylinder. This is part of the EWS security system, and it is used to read the chip from the key. My mechanic installed a new one from BMW and problem solved. Car has performed great since!

Thank you all for your help!!!