Z3 Will start sometimes and spin over others

I have a 96 Z3 with a transplanted 98' M3 S52 in it.

Ever since I have owned it, it has always taken 3 times to crank. Basically, turn the key and spin the engine, turn it off, turn on and spin, turn off and then turn it on again and it starts and runs perfectly.

Just recently it has been taking doing the on/off on/off on/off switching for as many as 20+ times before it starts and once again runs perfectly. It almost seems like it may never run and then when you've almost given up it starts.

Troubleshooting:
I have replaced the fuel pump (had a bad Gauge sending unit anyways)
Replaced the fuel filter
Replaced the Crank Position Sensor

I have then tried to reset the computer. I unplugged the negative on the batteyr and turned on the flashers to drain it.
After this it started on the first try for 3 times and then it went back to not wanting to start.

It seems to be getting worse to where it almost won't start.

Could this be the DME or a bad EWS?

Ok, I was able to reproduce the non-start issue with my Volt meter on the Fuel Injectors and it is getting Voltage to the injectors.

So it seems that the last thing is that I have no spark.

It DOES seem like a ON or OFF issue. Meaning that when it starts it starts perfectly, when it doesn't it just spins over.

It doesn't spin and then gradually start. Just a cycle of the key and it starts like something turned on.

you are getting an electrical signal to the injectors........are you getting fuel to them ? check for a signal from the crankshaft sensor

Originally Posted by wifesauto

you are getting an electrical signal to the injectors........are you getting fuel to them ? check for a signal from the crankshaft sensor

Yes, I am getting signal to the injectors. I varified with a Volt meter and the Crank position was replaced this week. Just not getting fire

the trick is to find out what you are not getting while cranking [no spark or no fuel or both] does EVERYTHING electrical work ok? [no wipers sometimes/radio sometimes]?i ask because if you have electrical bugs sometimes it makes your ignition switch suspect. did you confirm that you are getting fuel while cranking no start ?did you confirm spark [at plugs] during cranking no start?

Originally Posted by wifesauto

the trick is to find out what you are not getting while cranking [no spark or no fuel or both] does EVERYTHING electrical work ok? [no wipers sometimes/radio sometimes]?i ask because if you have electrical bugs sometimes it makes your ignition switch suspect. did you confirm that you are getting fuel while cranking no start ?did you confirm spark [at plugs] during cranking no start?

Getting signal to the fuel injectors as well as fuel pressure. It's totally a NO SPARK issue.

I need to figure out the circuit that provides the spark.

I found it, I figured it out.

I found a relay beside my DME that had some corrosion on it. I swapped it out with the main relay (same kind of relay) and the car started. I am ordering new relays to replace permenantly

good for you and thank you for the report back

Awesome fix. Well done figuring that out. I have been there done that on things.

Well done!

where abouts is this relay, sounds exactly like mine...

Originally Posted by Vanne

where abouts is this relay, sounds exactly like mine...

Mine is located right beside my battery, BUT since my car is a S52 swap I am not sure about location on a factory car.