2007 GTI fuel/electrical problem

[dean petrucelli]

hi all, first post and I hope someone can help. I have a 2007 GTI with a 4tec in it. took the ski for a ride and noticed it was not running up to full rpm. brought it back to my dock, shut it down and then tried to restart. it would not start. battery fine, connections fine, starter fine, etc. pulled boat and began to diagnose. found that the third cylinder injector is delivering fuel constantly while the key is in (you don't need to press the start button, just putting the key in begins the fuel flow from no. 3 injector only). this constant flow of fuel obviously flooded the no. 3 cylinder and locked the engine. once i removed all plugs, the engine turned over fine (yes, a boat load of fuel came out of cylinder 3) I switched the no. 2 cylinder injector with the no. 3 and the same problem, no. 3 injector still constantly delivering fuel when the key is in, therefore, not an injector problem. can someone please confirm that this is a ecu/ecm problem or can it be something else? is there any way to test for this to confirm? thanks for your help.

dean

 

[LargeJohn]

hi all, first post and I hope someone can help. I have a 2007 GTI with a 4tec in it. took the ski for a ride and noticed it was not running up to full rpm. brought it back to my dock, shut it down and then tried to restart. it would not start. battery fine, connections fine, starter fine, etc. pulled boat and began to diagnose. found that the third cylinder injector is delivering fuel constantly while the key is in (you don't need to press the start button, just putting the key in begins the fuel flow from no. 3 injector only). this constant flow of fuel obviously flooded the no. 3 cylinder and locked the engine. once i removed all plugs, the engine turned over fine (yes, a boat load of fuel came out of cylinder 3) I switched the no. 2 cylinder injector with the no. 3 and the same problem, no. 3 injector still constantly delivering fuel when the key is in, therefore, not an injector problem. can someone please confirm that this is a ecu/ecm problem or can it be something else? is there any way to test for this to confirm? thanks for your help.

dean

I just spent most of the summer learning and chasing a similar issue on a 2008 GTI.

There is a test procedure for voltage at the injector and continuity from the ECU harness to the injector that you should perform. All injectors should have battery voltage with the key installed. The ECU triggers the injector with the ground connection. If you don't have it already, download the manual for free. There is a good possibility that you have a corroded or broken connection between the ECU and the #3 injector.

 

[seadoosnipe]

hi all, first post and I hope someone can help. I have a 2007 GTI with a 4tec in it. took the ski for a ride and noticed it was not running up to full rpm. brought it back to my dock, shut it down and then tried to restart. it would not start. battery fine, connections fine, starter fine, etc. pulled boat and began to diagnose. found that the third cylinder injector is delivering fuel constantly while the key is in (you don't need to press the start button, just putting the key in begins the fuel flow from no. 3 injector only). this constant flow of fuel obviously flooded the no. 3 cylinder and locked the engine. once i removed all plugs, the engine turned over fine (yes, a boat load of fuel came out of cylinder 3) I switched the no. 2 cylinder injector with the no. 3 and the same problem, no. 3 injector still constantly delivering fuel when the key is in, therefore, not an injector problem. can someone please confirm that this is a ecu/ecm problem or can it be something else? is there any way to test for this to confirm? thanks for your help.

dean

It's been a while since I researched this, but it seems to me, it was a fuel pressure problem. When you get the ski ready to start, and put your lanyard on, the fuel system pressures up to a setpoint. There is also a recirc system that once that pressure is reached, it will allow excess fuel back to your suction side. The idea is, when your running WOT, and you let off the gas quickly, the pressure needs somewhere to go, fast, so the return line has a valve in it that opens. Because you troubleshoot with one of your other injectors, I'm going to believe you got a fuel pressure sensor that's not working properly. Also, if this was an issue with your ECU, it would def throw a code. You didn't mention it, so I assume there wasn't one. That tends to make me believe, it's not anything really super bad. You should also be able to find a line fitting, to check your fuel line pressure. I'd get a gage and check it. You could also find a way to block off that number 3 injector, then see what happens when you power up the machine. Blocking off the injector, powering it up, will let you know if there is a problem, because then the ECU will throw a code. Good luckj!

 

[dean petrucelli]

thanks. is there a fuel pressure sensor for each injector? if you tell me there is only one, then that doesn't make sense why 2 would work and one would not. anybody?

 

[ski-d00]

Fixed a few like this and almost all were bad ECU. Could be wiring connection or ground so should be checked first.

 

[LargeJohn]

Fixed a few like this and almost all were bad ECU. Could be wiring connection or ground so should be checked first.

+1

Check for ground/connectivity on the harness connector for the problem injector. Report back with what you find and we can go from there...