View Single Post
Old 11-29-2012, 09:22 PM   #26
Scooby Newbie
Member#: 235719
Join Date: Jan 2010
Chapter/Region: South East
Location: Pooler, GA
2006 STI


tldr: It started once and ran fine with a new fuel pump controller (see video) but then went back to sucking. Which line do I tee into to test the fuel pressure (see picture)? I think the problem is electrical and related to the fuel pump. Thoughts?

Ok so my progress on the car has been glacially slow, but I've managed to do a few things. I was convinced that it was either the fuel pump controller or the immobilizer so I bought a used fuel pump controller and a used ECU/key/ignition cylinder/immobilizer (from the same car) on ebay to try out. First I installed the fuel pump controller. Started it once and it died, as usual. Started it again and it ran fine, and showed no signs of dying. There was white smoke coming out of the exhaust and I wasn't sure if it was just condensation or signs of something bad. It was about 55deg F outside that day. Video here (sorry for the crappy angle):

Any thoughts?

Anyway I shut it off (bad idea) and started it again and it died, just like it used to. Then I tried just the new ECU by itself and it was a totally different set of problems. The security light came on and the car turned over but never fired once. I swapped it back and the car went back to starting up and then dying like it had been. This leads me to believe that its not the immobilizer. Also, it was basically on E and it had been sitting for a while so I filled it up with gas. Started it again with new gas, same thing.

Now I want to check the fuel pressure, but I'm not sure which line is the high pressure line. Can anyone tell me (I think those are the fuel lines...)?

Also, whenever it dies, the fuel pump starts making a loud funny sound right before the car dies (will post video). I monitored fuel pump duty with the green test connectors connected and it had no problem going from 0% to 33% to 100% and back to 0%, and it sounded just fine (and quiet). The dealership replaced the whole fuel pump unit recently so I don't think it's a bad pump. Also, the one time I was able to start it and keep it running, the car ran fine, and the fuel pump was quiet as a church mouse. Also, I did short the cigarette lighter socket shortly before the starting problems began. I think the problem is something electrical but I don't know where to look. Any ideas?

Line A is the fuel feed line. (43.5 PSI, car off)
Line B is the fuel return line. (0 PSI, car off)
Line C is the fuel vent line.
Now I know. Now you know.
* Registered users of the site do not see these ads.

Last edited by LaffyTaffy; 12-13-2012 at 06:50 PM. Reason: I learned it!
LaffyTaffy is offline   Reply With Quote