Trouble with Fuel Pressure Regulator
 

Hi,

I'm having trouble getting the fuelling right on my LT8 (in my FD with GT35/40 turbo). I think this being caused by FPR (Aeromotive A1000-6, see http://216.242.145.16/products/product.phtml?p=10). I have a large Bosch fuel pump, standard primary injectors and 1600cc secondaries.

When idling the fuel pressure is 40psi, on overrun its 36psi, but on 8psi boost @ 6000rpm it gets to approx 52psi and maybe even higher @ 7000rpm (I'm in 4th gear so I'm concentrating on the road!). I've had to back of the fuelling over 5000rpm so that the values actually drop all the way to 8000rpm. The injector opening times are dropping too (from reading the logs) !!

Why is this happening? The mechanic who installed the FPR put it in between the fuel pump and 2ndry injector rail. Is this correct? There are no leaks. BTW I'm tuning with the Tech Edge v2.0 wideband.

Thanks in advance for any helpful advice,

Adrian
(in UK)

more info
 

It's probably unrelated but I've also got an a problem idling, as the engine usually stalls after 15-20secs, even though it's reading approx 12.5 on the wideband and feels smooth. It also cuts out very quickly as I drive up to a junction (push down the clutch) and try to let it idle.

The TPS has given me problems in the past, but even though the '*' is correctly set on TPSCal, I'm sure that sometimes I see "TPSCal" appear on the Status bar (on my Laptop) when the engine's about to stall.

BTW I have the LT8, the FPR and a boost guage running off the same nipple that standard ECU used to run off. And a BOV on one of the intake runners.

Thanks,

Adrian

That's why. It's a rising rate regulator.

FPR pressure
 

I understand that, but it is more like a 2:1 rise as the boost is only 8psi (ie. on the WG spring). It also rises with revs, not just boost!

Are you supposed to put the FPR in between the fuel pump and 2ndry injector rail? The FPR manual says no, but my mechanic says yes.

the regualtor is suppose to go between the secondary rail and the return line, not between the pump and the rail
Dale