Turn the key and it turns over a few and then drops off. after 2 or 5 times it will complete the start and run. It is slowly getting worse each day.. Thinking Crank position sensor or Relay control Modual. any ideas.. Been working 12 hour days so trying to get anything done is frustrating right now.

 

Not everything is caused by electrical fault.

Get in, close door.
Turn key to "ON", wait till the fuel pump stops running (you can hear it, maybe 5-6 seconds).
IMMEDIATELY, turn key to "start" - does engine start up fine? If so, you have low fuel pressure / fuel pressure that builds up too slowly.

Buy higher pressure fuel!

 

Great Tip... Should have thought of that.... I will pick up a few gallons of high pressure fuel on the way home tonight I have a spare pump from my SLK days so that could be a good find.

 

I hope you have the special containers for the high pressure fuel, otherwise it was nice knowing you .

 

I got a 4 pack at Harbor freight on clearance

 

Then what could possibly go wrong ?

 

I think the next line is hold my Beer...

 

Ok after throwing my hands in the air it ended up being the RCM. seems even my spare one was bad... Cant see anything wrong with it but replaced it and works like a charm.

 

Thanks for posting a follow-up! Knowing a solution helps us all understand our cars better.

 

Send me the bad RCM to get it refurbished so you have a good spare!
Email me at tighed1@hotmail.com for details.

 

will do thanks

 

Glad you have it running again! WOW, two bad RCM's? How often do you hear about THAT?





You have been quite a good diplomat for the XF and membership! I know many have thanked you, I should also. Thanks for your neverending help to the membership!


.

 

Well it came back again but different. Died on me then wouldn’t start. Just like a CPS going bad crank but no start. Took it back to the shop and he drove it around a bunch until it died on him.

He plugged in another K40 and car did nothing. Then he really dug in and found that one of the female connectors inside the plug was broken and barely making contact. Replaced that and it has been problem free for 3 days. Fingers crossed

 

This happened to me on a non crossfire situation. There are 5 connectors on my saturn's engine harness. One of those connectors was having an intermittent connection. Because the problem code was somewhat unique I thought I would have a "professional" track down the problem. Two trips to the service department, Three weeks waiting and $1100 later the problem got solved. When dealerships have $120 hourly rates and they are really just experimenting; things can get out of hand. I'm happy for you that you had a competent mechanic working on the car.