Strange 535i starting Problem???

[Bill R.]

Well, I thought maybe cleaning the crank position sensor would have helped but...this morning I'm back to square one.

I've cranked it over for 10 minutes and not even a prayer.

Any ideas would be appreciated

[islandphile]

Thanks Bill...Where are those located and how are they checked??

[Bill R.]

Thanks Bill...Where are those located and how are they checked??

[islandphile]

It's a 1991 e34 auto.

I just took a pic of the fuse box & relays...Is this where I should be looking?

http://www.sounddomain.com/memberpage/392547/4

[Bill R.]

passenger side. The closest one to the fender is the fuel pump relay...the orange one in the pic here... the white one is the dme or main relay..


To troubleshoot it remove the relay and jumper across it. Frequently just removing and replacing the relay will clean the contacts enough that it will start working again...but if not jumper across the relay and see if the car will start.

It's a 1991 e34 auto.

Here is a link to a pic of the relays to make pointing it out easier.

http://www.bmwe34.net/e34main/mainte...trical/LKM.htm

[islandphile]

Cool man...I'll try that right now!!!

[islandphile]

Well...the relays work fine...This is one of those times I just want to take a sledge hammer to it...

I looked on a Bocsh K-Jetronic trouble shooting page for some help.

http://www.forparts.com/techbosKjectronic.htm

Do I have an Aux air valve on the m30 motor? Or a sensor plate? If so where are they and should I check those too?

[Bill R.]

by the fuel tank... if its running then put the relay back in and have someone crank the engine with the coil wire removed from the coil and held about 1/2 inch away... do you see spark when its cranking... If you do then check for spark from the dist cap to the plugwire by pulling a plugwire on one cylinder where it goes into the cap and holding it about a 1/2 inch away and cranking.. if spark visible there...If the fuel pump is running and you have visible spark then you need to get a noid lite and check the injector harness to see if the injectors are triggering...

Well...the relays work fine...This is one of those times I just want to take a sledge hammer to it...

I looked on a Bocsh K-Jetronic trouble shooting page for some help.

http://www.forparts.com/techbosKjectronic.htm

Do I have an Aux air valve on the m30 motor? Or a sensor plate? If so where are they and should I check those too?

[islandphile]

by the fuel tank... if its running then put the relay back in and have someone crank the engine with the coil wire removed from the coil and held about 1/2 inch away... do you see spark when its cranking... If you do then check for spark from the dist cap to the plugwire by pulling a plugwire on one cylinder where it goes into the cap and holding it about a 1/2 inch away and cranking.. if spark visible there...If the fuel pump is running and you have visible spark then you need to get a noid lite and check the injector harness to see if the injectors are triggering...

Thanks Bill.

Now, lets remember that this problem ONLY appears when the engine is cold.

Once it runs even for a couple of minutes, it will start for the rest of the day, and once up to temperature it will start after sitting for up to 5-6 hours...it just WON'T start in the morning **scratches head**.

My guess is it is something to do with a sensor in the Fuel Injection System that needs to warm up, I just don't know which one.

Bill, BTW, the fuel pump is just 3 weeks old and like I said once the car starts it's smooth sailing for the rest of the day...if I only knew why it won't start.

[islandphile]

I didn't want to do this but looks like I'll just have to start replacing sensors one by one to see which one it is.

So no one has had this Cold Start Problem???