S5 Turbo Fuel Issues

vrracing · 09-04-2016, 12:18 PM

It's really hard to tell from the posts what is actually happening.

"When you use the jumper on the yellow connector it purrs like a kitten."

suggests that it runs fine if the jumper is connected.

But then right after that...

"Pete_89T2 -So when you jump the yellow check connector the FP runs as it should."

to which you respond...

"Even tried that. It still wouldn't start more than a second."

If it "purrs like a kitten" with the yellow jumped but dies if you pull out the jumper, I'd look at the AFM. IIRC, there is a safety feature that if the AFM isn't telling the ECU there is air flowing (that is, the engine is running) then the ECU cuts the fuel pump. That way, if you wreck with the key on, the fuel pump doesnt feed gas to the impending explosion. That is disabled when the key is in "start" as opposed to run because obviously the engine isnt turning over enough to activate the AFM.

Hope that helps.

09-04-2016, 12:18 PM	#7
vrracing Rotating Assembly Join Date: Oct 2008 Location: TX Posts: 102 Rep Power: 18	It's really hard to tell from the posts what is actually happening. "When you use the jumper on the yellow connector it purrs like a kitten." suggests that it runs fine if the jumper is connected. But then right after that... "Pete_89T2 -So when you jump the yellow check connector the FP runs as it should." to which you respond... "Even tried that. It still wouldn't start more than a second." If it "purrs like a kitten" with the yellow jumped but dies if you pull out the jumper, I'd look at the AFM. IIRC, there is a safety feature that if the AFM isn't telling the ECU there is air flowing (that is, the engine is running) then the ECU cuts the fuel pump. That way, if you wreck with the key on, the fuel pump doesnt feed gas to the impending explosion. That is disabled when the key is in "start" as opposed to run because obviously the engine isnt turning over enough to activate the AFM. Hope that helps. __________________ 90 S5 Vert. JDM Tii with BNR Stage1 turbo. Pineapple Racing street port. Bonez cat-forward. Corksport cat-back with Vibrant UltraQuiet resonator. RTek 2 wZeitronix w/b. HKS EBC. Vis CF Tii hood. 3000GT wing. Ground Control coilover kit with KYB AGX shocks. Red and Black leather RX8 seats. Corksport Odura lip & bumper caps, OEM Tii skirts Last edited by vrracing; 09-04-2016 at 12:41 PM.