cranks but won't start

[671rover]

Hi, it's been a while since I posted. Having issues with my 1M, engine cranks but won't start. Vehicle has 20,000 miles, no mods.

Last time I drove it, it started up right away and that was 1-2 months ago. Battery is on a trickle charger 2 days (weekends) a week. I connected a battery pack jumper to the jumper post in the engine compartment thinking the battery voltage was low causing lower cranking speed but still won't start.

No check engine light. I checked the fuses related to fuel behind the glove box and all seem fine. I noticed the priming of the low pressure fuel pump is not happening when I unlock the doors. Defective LPFP/fuel control unit or something else as simple as a fuse or a relay?

Next, will be checking all the fuses behind the glove box before I check the LPFP

Richard

[werman]

If you hook the trickle charger up, does it have an indicator which confirms that the battery has a full charge? Is your battery jumper fully charged and sufficiently powerful to instantly fire up the engine? I’m still hoping it’s something simple. Good luck.

[iDontRemember]

Do you have protools? You can monitor your fuel pressures and lpfp voltage.

[dbc1m]

I have the p3 gauge plugged into the OBD port and one time it happened to me that it would just crank and not start.
Reseated the p3 cable at the obd port and all good
not sure if you have anything plugged in but that’s my 2 cents
Good luck

[671rover]

Originally Posted by werman

If you hook the trickle charger up, does it have an indicator which confirms that the battery has a full charge? Is your battery jumper fully charged and sufficiently powerful to instantly fire up the engine? I’m still hoping it’s something simple. Good luck.

Yes battery charger is a pulsetech XC100-P it has a meter that tells you what percent of the battery is charged. Meter shows 100% Battery pack also has a screen showing 100% charged.

[671rover]

Originally Posted by iDontRemember

Do you have protools? You can monitor your fuel pressures and lpfp voltage.

No, don't have that.

[671rover]

Originally Posted by dbc1m

I have the p3 gauge plugged into the OBD port and one time it happened to me that it would just crank and not start.
Reseated the p3 cable at the obd port and all good
not sure if you have anything plugged in but that’s my 2 cents
Good luck

I have nothing plugged in the OBD port

[671rover]

Checked all the fuses behind the glove box with an ohm meter, all good. Will be checking the fuel control unit by the rear passenger seat back. Hopefully this is it, maybe something weird happening at the connection.

[DarthColin]

Based on my limited mechanic abilities (but not afraid to attempt work above my pay grade), and you mentioning that you don't hear the LP prime pump upon doors unlocking, I'd say concentrate on why that's not happening.

[CarJunkie]

Originally Posted by DarthColin

Based on my limited mechanic abilities (but not afraid to attempt work above my pay grade), and you mentioning that you don't hear the LP prime pump upon doors unlocking, I'd say concentrate on why that's not happening.

Agreed . . . sounds like a fueling issue. OP, do you smell fuel after cranking? If you have a no spark issue, the exhaust will smell like gas after a few long cranks.

[671rover]

Originally Posted by DarthColin

Based on my limited mechanic abilities (but not afraid to attempt work above my pay grade), and you mentioning that you don't hear the LP prime pump upon doors unlocking, I'd say concentrate on why that's not happening.

Can you confirm by unlocking your doors that when the door unlock the LPFP primes? And the priming sound is quit loud right?

Originally Posted by CarJunkie

Agreed . . . sounds like a fueling issue. OP, do you smell fuel after cranking? If you have a no spark issue, the exhaust will smell like gas after a few long cranks.

I thought I smell gas initially when the car would not start after several cranks but I checked the last time I try to start it with my nose right up against the exhaust and nothing.

[Daz1]

fuel pump seems logical if you can't hear it. please post the fix. interested to know the outcome. good luck!

[Boost3d_1M]

Firstly have you read the car for codes?

I had a similar issue on my other n54 and I am going to hazard a guess and says its your EKPM

[671rover]

Originally Posted by Boost3d_1M

Firstly have you read the car for codes?

I had a similar issue on my other n54 and I am going to hazard a guess and says its your EKPM

No check engine light so I assume no codes. I got access to the fuel control unit (EKPM), just thought I unplug and replug it but still the same. Will check on the fuel pump and test it. If my fuel pump runs by connecting 12v to it then it's most likely the fuel control unit. When you replaced the fuel control unit (EKPM) on your other N54 did you have to program (register) the new unit in?

[Boost3d_1M]

Just because you dont have an engine light, doesnt mean a shadow code wont be triggered or a fault isn't present. For me the first two steps is always to read the codes and then if possible or viable do a log.

Secondly , yes the EKPM needs to be coded, especially if its a new item

[671rover]

Tested the fuel pump and it's good but somehow the sound didn't seem to be coming from where the fuel pump is located (under the rear passenger seat). I can barely hear the fuel pump prime when I push the start/stop button without depressing the clutch pedal.

It was a bad camshaft position sensor (intake). The original one was not putting out any signals when I placed a metal object to it. Started right up after replacement.

[671rover]

Originally Posted by 671rover

Tested the fuel pump and it's good but somehow the sound didn't seem to be coming from where the fuel pump is located (under the rear passenger seat). I can barely hear the fuel pump prime when I push the start/stop button without depressing the clutch pedal.

It was a bad camshaft position sensor (intake). The original one was not putting out any signals when I placed a metal object to it. Started right up after replacement.

Vehicle was running fine prior, no stuttering/loss of power. Guess the camshaft position sensor just decided to quit after I parked it.

[CarJunkie]

Originally Posted by 671rover

Vehicle was running fine prior, no stuttering/loss of power. Guess the camshaft position sensor just decided to quit after I parked it.

Interesting. Thanks for the follow-up!

[671rover]

Originally Posted by CarJunkie

Interesting. Thanks for the follow-up!

No problem. From what I gathered, usually it's the crankshaft position sensor that causes the crank no start. Hopefully this will help someone if they have issues.