Jump to content
  • Welcome to 205GTIDrivers.com!

    Hello dear visitor! Feel free to browse but we invite you to register completely free of charge in order to enjoy the full functionality of the website.

Sign in to follow this  
Edd-XS

Fuel Pressure Too High?

Recommended Posts

Edd-XS

right im writing this on behalf of a friend of mine.

Basically he has just spent the weekend swapping a 1.9 lump over into his Gti. He drove the donor 1.9 to his workshop no problems, swapped the lot over but it doesnt seem to want to run properly. On closer inspection he says that hes got far too much fuel pressure, but hes not sure what could be causing it? Hes swapped over the fuel pump, relay and loads of other bits and its still saturating the injectors.

Has anyone got any ideas what could be causing this? Im just forwarding the message as he doesnt have the net!

Thanks alot

Edd

Share this post


Link to post
Share on other sites
hengti

presume it's not fitted with a FSE - ?

  • Like 1

Share this post


Link to post
Share on other sites
Edd-XS
presume it's not fitted with a FSE - ?

correct! just a standard fuel pump...

Edd

Share this post


Link to post
Share on other sites
hengti

pls excuse me if this sounds at all condescending - no idea of your experience

 

 

the fuel pump is completely unrelated to a FSE - which is a replacement for the fuel pressure regulator (on the end of the fuel rail)

 

FSEs are adjustable - if it's got one fitted, it could account for the pressure problem

 

just a thought anyway

Share this post


Link to post
Share on other sites
Edd-XS

sorry my bad! I thought the FSE was almost like a second fuel pump... all i know is apparentely they're abit of a waste of time! But no i know he doesnt have one fitted.

Edd

Share this post


Link to post
Share on other sites
Anthony

If he is genuinely getting excessive fuel pressure, then the problem has to be either with the fuel pressure regulator (on the end of the fuel rail), vacuum feed for the FPR (lowers fuel pressure on low throttle openings), or a restrictive fuel return pipe.

 

However, problems with high fuel pressure are pretty damned rare, and problem is much more likely down to overfuelling due to management related issues (bad ECU temp sensor is the usual one, and if he's done an engine swap a ECU/AFM/injector mismatch of 1.6 and 1.9 parts is another)

Share this post


Link to post
Share on other sites
Richie-Van-GTi

Not sure how the wiring works but could he of got a wire wrong somewhere that goes to the fuel pump relay so its permanently on rather than pulsing according to engine speed and throttle position?

Share this post


Link to post
Share on other sites
Anthony
Not sure how the wiring works but could he of got a wire wrong somewhere that goes to the fuel pump relay so its permanently on rather than pulsing according to engine speed and throttle position?

Fuel pump runs all the time. Fuel that isn't required is simply returned to the fuel tank via the fuel return line.

Share this post


Link to post
Share on other sites
Richie-Van-GTi

really, I thought the TPS switch was to shuit the fueling off or is it the injector opening times that are effected?

Sorry to thread snatch but its good to ge all this info in my own head :rolleyes:

Share this post


Link to post
Share on other sites
jackherer
If he is genuinely getting excessive fuel pressure, then the problem has to be either with the fuel pressure regulator (on the end of the fuel rail), vacuum feed for the FPR (lowers fuel pressure on low throttle openings), or a restrictive fuel return pipe.

 

However, problems with high fuel pressure are pretty damned rare, and problem is much more likely down to overfuelling due to management related issues (bad ECU temp sensor is the usual one, and if he's done an engine swap a ECU/AFM/injector mismatch of 1.6 and 1.9 parts is another)

 

I agree, unless hes used a pressure gauge to measure at the rail theres no way he could know, its going to be one of the things Anthony mentions.

 

 

really, I thought the TPS switch was to shuit the fueling off or is it the injector opening times that are effected?

Sorry to thread snatch but its good to ge all this info in my own head :rolleyes:

 

yeah the TPS sends a signal (on or off) to the ECU which then cuts the injectors. The pump runs constantly as long as the engine is turning over, its controlled by the tachometric relay (the tacho part means rotation/revs like the rev counter...).

Share this post


Link to post
Share on other sites
maxi

Whoever your mate is Edd, Im not to happy about my phone number being given out and him just ringing me randomly while im busy at work asking stupid ass questions.

 

The car is overfueling since he has done the swap. I think you will find it has sweet FA to do with excess fuel pressure and he is pissing in the wind anyway without a pressure gauge.

 

Maxi

Share this post


Link to post
Share on other sites
Sign in to follow this  

×