Car has been driving like crap for a while, and I finally realized my fuel pressure was low. I immediately reverted my wiring back to stock (was running pump wires to a kill switch), and the car got a lot better, but still isn't 100%.

Wondering if MY wiring that had gone bad caused the fuel pump to start to die.

Would like to know some specs I could use to diagnose its condition, ie; whats the resistance I should see on the pump leads, how fuel pressure should react under boost, etc.

01 225hp TT, no chip, adjustable boost controller. Car starts studdering in low boost.

Thanks

 

Ok.. first thing to check is whether you have full voltage at the pump. Audi says with in 2 volts of battery, but I would thing you could get it to with in .5v.

Second, the pressure should be 2.5 bar (36psi) at idle w/ regulator hooked up, 3.0 bar (44psi) w/ the vacuum to the regulator off. After 10 mins of sitting, off, there should be at least 1.5 bar (22psi)

Next, you could remove the return lines and actually measure the amount of flow.. You run the pump for 15 secs and measure the amount you get.







So, at 12v to the pump, your looking at at least 375 milliLiters in 15sec.

 

Looks like im about 36psi with vac removed. 25ish (maybe slightly higher) with vac applied. Gauge doesnt have the best resolution, but its obvious its low. Still need to test voltage. Need daylight to see what Im doing, so that'll have to wait until tomorrow.

 

Im gonna get a little ahead of myself and just say walbro FTW...

 

Ya.. your about 10psi low.. Doesnt mean its your pump, though. Could be the regulator is weak.

 

borrowed a friends 4 bar.... no change...


looking for an apparently elusive fuel pump, possible alternative to the walbro..

034 lists it as the "005", and I can't find many places to get one, except from them, and they list it for $225. Found a vehicle manufacturer p/n with Ferrari, but that's not gonna help lower the price... crap. Went on their crappy ugly cars of the 80's... 412, Mondial, etc...

 

Well, figured I'd go all out. Made a 'best offer' bid on ebay for a Bosch 044 pump. 5 bar, 200 liters/hr. Should cover my fueling needs beyond anything I have planned for the car at this point.