I just picked up my FD 2 days ago. It ran fine until yesterday when I started it up and for the first 10 minutes or so, it would feel like it was starving for fuel if I did more than gently step on the gas and once it hit more than 7psi it would do the same thing and run very sluggish. Then it seemed to fix itself. This morning I had the same problem but now it won't go away. I just replaced the fuel pump 5 minutes ago and had no luck. It doesn't seem like a filter issue because the problem fixed itself yesterday on it's own. I am running the stock twins, FMIC, intake, exhaust, DP, it still has the stock cat on it (which i am replacing immediately), Power FC, Apexi Elec Boost Control and SAFC 2. The only thing i've done is turn down the boost from 13psi to 10psi for daily driving. Please help me I just got this car and I am already dumping money into it!

 

It's normal for it to lag when you gently press the gas pedal while the car is cold to a certain extent.

Change your fuel filter anyway. I can bet that will help a lot.

Also check your FP relay.

 

it definetly lags more than it should. i can bearly get it to go past 5000rpm. that relay issue definelty makes sense tho, especially since it was doing it intermittently yesterday. does the high pressure relay kick in only when more gas is called for (giving more throttle) or when it hits higher RPMs?

 

See section F of the FSM, page F-108


EDIT: Yes, the relay control is speed/load based. I don't know what the exact criteria are...

 

so i'm assuming the pump is normally on low pressure and the relay kicks in the high?

 

nevermind it's in the manual. i'll just look in there from now on LoL. FDs are definetly more complicated than my 8. What do u think a near mint condition 93 FD with 55k miles is worth anyways? i traded it for my 8 which was prolly worth only $16000

 

I'm 90% sure it's your relay. Those relays have been giving me a hard time recently, or at least the headlight and TNS relays. Take out the fuel pump relay, take off the cover, and clean it up a little. If that doesn't work then you'll just have to get a new one.

 

I replaced the fuel pump yesterday with no luck for improvement. Somehow the problem fixed itself again today, and then I went to start it up again and ran into the same problem. I checked for continuity on my relay and it checked out ok. I'm very confused as the what the problem may be now.

 

strangly enough i fumbled around with the boost control, turned it all the way down, and although the boost levels stayed the same..????? the problem fixed itself again. wtf is with my car LoL i'm bout to go have it professionally tuned.