Notices

Fuel pump priming condition?

Thread Tools
 
Search this Thread
 
Old 04 August 2017, 09:09 PM
  #1  
mapa
Scooby Newbie
Thread Starter
 
mapa's Avatar
 
Join Date: Jul 2015
Location: The track
Posts: 16
Likes: 0
Received 0 Likes on 0 Posts
Default Fuel pump priming condition?

Hey guys, I'll start from the very beginning...
2005 STI. Turbo water hose bursted one night, so I decided to change all water hoses. To do that we had to pretty much disassemble most of the engine and everything surrounding it - so far so good (still waiting on the hoses...). While waiting for the hoses, I though it's the best time to get the fuel lines going to my external regulator replaced with proper durable hoses, so far so good... Then I though "why bear with the buzz of the external 044?", so I got a new walbro 450 which would replace my pick up pump and the bosch all together. Everything was going well, we fitted the walbro in the hanger, got the new wiring soldered and installed the pump. Now the fun part begins... I knew I needed to get a 12v directly from the battery to power the new pump - done. But while fiddling with the fuel pump controller and trying to figure out how to wire the new relay's signal, a small spark appeared . Basically the idea was to use it's signal wires to energize the new relay, which would then feed the pump directly from the battery.

TL;DR
Fuel pump won't prime after fiddling with the wires going to the fuel pump controller (possibly shorting something) and half of the engine bay is disassembled.

I kind of paniced and decided to see if something blew so I just hooked up the pump... surprise - it didn't prime.

What we found:
- Fuel controller doesn't start the pump
- When turning ignition on, the two thin wires going into the controller (they come from the ECU) don't do anything, voltage stays at 0v, no resistance change, no ground connects, etc - what exactly are they doing?
- All fuses and relays are fine (unless there is a hidden one somewhere?)
- The fuel pump controller gets 12v from one of the wires
- Fuel level stays at the bottom, fuel light is on

What we tested:
- Fuel pump main relay - tested and OK
- Fuel pump - tested with direct 12v and OK
- Fuel pump controller - It was disconnected when the spark happened
- Fuel pump wiring from controller to pump - tested and OK

Now the question is:
- What could have gone wrong?
- Fried ECU? Is it possible if I somehow sent current TO the signal wires?
- Can only parts of the ECU die? When the ignition is on, the dash does stuff, check engine is on (from maf and what not), the DCCD light blinks (possibly because of disconnected sensor), etc.
- ECU detects that some connectors in the engine bay are disconnected and prevents fuel from flowing? All timing/cranking/alternator wiring is still connected.
- Fried wire somehow somewhere?

I would really appreciate any help...




All times are GMT +1. The time now is 08:30 PM.