Fuel pump not priming

[Itsgerman]

Backstory: Motor broke a ringland 1 year and 3months ago, it then sat in my garage for that duration untouched while i got funds to swap the motor but then decided to change the turbo kit and build the trans etc. the car would still start and idle when it blew up. While it sat the battery completely died and im unsure for how long but i changed the battery as it was getting close to towing it to my guy who will help me swap the motor and do the turbo kit etc. the day before the tow i went to start the car(to make sure i could get it in neutral) and it would crank for awhile then start but die within 2-3 seconds. I cleared the codes and cranked it again and it would do the same thing i read the codes and there was a fuel rail pressure low code, cant remember the exact code. It would still crank long enough to atleast get it in neutral.

The issue: Now that we have swapped the motor the main fuel pump will not prime or do anything. I have flashed the dme back to factory and the reflex is not plugged in. The car did sit in pump e85 that whole time so thought maybe the pump just died from that BUT heres the kicker when you unplug a dme connector and put the car in the on position it will kick on the pump and run indefinitely until battery is unplugged all the while gushing fuel out of the fuel line. One thing to note that changed with the fuel system is i swapped to a precision raceworks standalone port injection kit and when i called them they said the main line fuel side has nothing to with reflex as it plugs into the factory harness and operates the stock pump as normal where as the aux side is completely separate. We are at a loss atm on what to do. I have a guy coming next week who has full ista access to see if it can point in any direction but figured id post here just and see if any ideas could arise. As of now it seems the pump does work when it gets power but when everything is hooked up as normal its not getting signal to prime for whatever reason.

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[rottmore]

Jesus, those are a lot of codes... The only thing I can think of is that since you swapped the motor, it's possible that there's harness damage somewhere on the car or something is not properly grounded. It feels like some of these codes are putting the DME into a protective mode.

I dunno man, I'd just start by fully charging the battery. Hook up the car to a stable power supply while in diagnostic mode and start to probe the fuses and relays to get clues on electrical issues and should point you in the right direction. Then inspect the entire wiring harness from end to end for any damage or if all grounds are secure and clean. Also doesn't hurt to double check every connector to see if its properly seating.

 

[Itsgerman]

Jesus, those are a lot of codes... The only thing I can think of is that since you swapped the motor, it's possible that there's harness damage somewhere on the car or something is not properly grounded. It feels like some of these codes are putting the DME into a protective mode.

I dunno man, I'd just start by fully charging the battery. Hook up the car to a stable power supply while in diagnostic mode and start to probe the fuses and relays to get clues on electrical issues and should point you in the right direction. Then inspect the entire wiring harness from end to end for any damage or if all grounds are secure and clean. Also doesn't hurt to double check every connector to see if its properly seating.

Most of them are ignorable due to the car having a stock tune in it and the car having the evap deleted and top mount turbo. The battery is new and we put a battery tender on it while testing different things.

 

[rottmore]

Most of them are ignorable due to the car having a stock tune in it and the car having the evap deleted and top mount turbo. The battery is new and we put a battery tender on it while testing different things.

Yea some of the them are nothing burgers. But rereading your post saw that you had a low fuel pressure code and car would die within 2-3 seconds before the swap which is weird, but not sure if its related to your current issue. I would chalk it up to the e85 sitting for a year and water buildup in the tank.
Assuming you register the battery with bimmerlink or protools? Yea it's a new battery but you just want to make sure its fully charged for before you start probing the fuses just to rule out any other variables so you can see if its an upstream power or controller issue. Also is the reflex connected via a PnP harness or posi taps? If its posi-taps I'd inspect the taps again just to make sure the wires aren't damaged. It possible the reflex taps could have been pulled or caught on something during the swap.

 

[Itsgerman]

Yea some of the them are nothing burgers. But rereading your post saw that you had a low fuel pressure code and car would die within 2-3 seconds before the swap which is weird, but not sure if its related to your current issue. I would chalk it up to the e85 sitting for a year and water buildup in the tank.
Assuming you register the battery with bimmerlink or protools? Yea it's a new battery but you just want to make sure its fully charged for before you start probing the fuses just to rule out any other variables so you can see if its an upstream power or controller issue. Also is the reflex connected via a PnP harness or posi taps? If its posi-taps I'd inspect the taps again just to make sure the wires aren't damaged. It possible the reflex taps could have been pulled or caught on something during the swap.

It's a tms plug n play harness for the reflex, we did register the battery via bimmerlink. We did check some fuel related fuses but didn't check all fuses yet so that is something we will do next time we mess with the car.

 

[Thraxbert]

Make sure that the EKP is grounded correctly on the chassis. It's under the rear deck lid. Two black boxes going to a silver tab with two brown wires.

At 17,564 miles, the nut on that post backed itself off on my car. EKP was no longer grounding reliably, and I had many of the issues you are describing.

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