stock 93 AWD< no fuel pressure rise and only 9 PSI of boost?? WTF???

[jetdriven]

I just put in my autometer electric FP gauge and a new VDO boost gauge.

The car idles at 19" VAC and only gets 9 PSI of boost. Fuel pressure at idle is 30 PSI, with the vacuum hose disconnected it is 40, and there is no rise of fuel presuure under boost.

WTF is going on? This car hits real hard at 3,000 RPM and by 5 grand it doesnt pull very hard anymore.

Im thinking that my FPR is bad, is it? ...And is only 9 PSI of boost stock normal?

This is a stock 1993 TSi AWD with a 6-bolt motor and only mods are a K&N filter and a test pipe.

Comments, suggestions? POST THEM HERE. Thanks.

 

[stay tuned]

yea man sorry to let you down even though the dash says 14psi, you should know factory dash is always way off when i installed my autometer boost gauge last week i only had nine psi also...i have a cut air can with new air filter, full 3 inch exhaustboost controller with the boost raised to 14 psi and the car is running alot quicker but it gets fuel cut i need to do the fuel system...

 

[EHeye]

yah that is normal man, the stock FPR is regulated for 37psi, stock psi is 9psi, remove the BCS restrictor and you will get a bit more boost. Bigger exhaust (press bent is cheap and does the trick) will allow quicker spool up and the 14b turbo does fall off at about 5000-6000rpm depending on mods, it will also start just blowing hot air above 18psi. without any free mods or anything keep the boost at about 13psi, better to be safe than sorry.

 

[jetdriven]

shouldnt the fuel pressure rise 1:1 with boost?

 

[nine5raptor]

yeah the fpr is ####ed

 

[nine5raptor]

Originally posted by jetdriven
and there is no rise of fuel presuure under boost.

Im thinking that my FPR is bad, is it? ...And is only 9 PSI of boost stock normal?

yeah it is bad. The fuel pressure should rise with boost pressure to maintain the the pressure differential accross the injector. W/o the pressure raising, you are running lean and knocking because the ecu is adding fuel based on a constant delta p which you don't have.

 

[pneumo]

you might want to check the FP gage to make sure it can read accurately. I had the same problem until I found out my FP gage sender was crap.

 

[jetdriven]

i pinched off the return line with a pair of pliers and the pressure went to 60 at idle. I believe the gauge is reading right. When I get home tuesday I am changing the regulator out.