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

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.

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

Cleaned the front crank sensor and seems to make the pump pulsate but no crank

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.

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?