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Old 09-15-2014, 01:17 PM   #61
BMW_Hatchback
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Voltage was measure with fuel pump relay unplugged by placing a volt meter across fuel pump relay coil receptacle tabs outside fuse panel. If I connect negative lead to chasis and positive to fuel pump relay coil receptacle I get 12v. I discovered the negative wire for fuel pump relay goes back to the DME box. I also discovered I have NO voltage to spark plugs and I am not communicating with the OBD port. Could it be crank sensor or DME unit? Thanks again.
We've got a third Ti that is experiencing this behavior. Codes came up empty. New fuel pump doesn't prime when in on position

We jumped the fuel pump relay and the pump does buzz/prime. However, the car doesn't turn over with a new battery, new fuel pump, plugs, VC gasket. Fuse 18 is good too.

We also pressure tested at the rail and got 45 PSI when we jumped the FP relay socket.

Here's a video of how it sounds, ignore the starter fluid fail:

https://www.dropbox.com/s/djy4tjkh4o...84122.mp4?dl=0
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Old 09-15-2014, 11:06 PM   #62
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Sounds to me like you need to do a compression test. My internet guess is there is little or no compression since it cranks over like there are no spark plugs installed. Also it sounds horrible when you are cranking the engine over, like starter flywheel issue or timing chain issue.
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Old 10-04-2014, 08:29 PM   #63
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What triggers the dme ?

I tested all pump relays and 18 and all pun click and power ? Still no turn on when I crank the car
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Old 10-04-2014, 09:05 PM   #64
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Cleaned the front crank sensor and seems to make the pump pulsate but no crank
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Old 10-05-2014, 03:00 AM   #65
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Like Pierre said -- relay is all or nothing. If it failed you get zero out. If you get anything, the relay is working. The load of the starter is pulling down the battery voltage.
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Old 10-12-2014, 04:17 AM   #66
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What triggers the dme ?

I tested all pump relays and 18 and all pun click and power ? Still no turn on when I crank the car
To answer for anyone that wants to know. The DME is energized by the unloader relay when cranking, after car starts I believe it is powered by the main system relay (Not 100% sure). The DME will not turn on the fuel pump relay unless it detects engine rotation from the CPS. Hope this helps.

After reading a little more I think there are two people with motor cranks no start. The only time I've had this issue was when the unloader relay was not working. The unloader relay powers only items needed to start the car. When you crank your car over the radio, lights and other items that are not needed to start the car will not get any power so there is more power to crank over the motor. Also my unloader is located in the DME compartment clipped right to the DME...

John S

Last edited by xxxJohnBoyxxx; 10-12-2014 at 04:24 AM. Reason: added about unloader
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Old 10-12-2014, 04:59 AM   #67
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Quote:
Originally Posted by xxxJohnBoyxxx View Post
To answer for anyone that wants to know. The DME is energized by the unloader relay when cranking, after car starts I believe it is powered by the main system relay (Not 100% sure). The DME will not turn on the fuel pump relay unless it detects engine rotation from the CPS. Hope this helps.

After reading a little more I think there are two people with motor cranks no start. The only time I've had this issue was when the unloader relay was not working. The unloader relay powers only items needed to start the car. When you crank your car over the radio, lights and other items that are not needed to start the car will not get any power so there is more power to crank over the motor. Also my unloader is located in the DME compartment clipped right to the DME...

John S
Interesting info, got any pictures?
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