Finished F1A build and running massivly lean

[Ukfox89]

Just finished my F1a build, drove it few weeks ago on stock returnless fuel system with 80lb injectors and sct5000 mass air, drove great.

Installed a Fore return style fuel system with 340E pumps, and installed a start up tune. fuel system works fine, pressures up great and everything. start the car, fires up okay, hunts when idling, and stutters. air fuel gauge is 18-20:1, you can blip the throttle and it slightly richens up for a split second and then goes back to really lean. tried adjusting the fuel pressure at the regulator and it changes, but the Air fuel remains the same. other than the tune, any other ideas? what can I data log to see if its the tune? Fuel pressure right now is around 48psi while running, I have adjusted to high 30s and low 50s with no change in running condition.

Thanks Ben

 

[ctgreddy]

Have you contacted whoever you got the base tune from and see if they have any ideas? Unless something is really wrong with how you installed the fuel setup, then it sounds like it's gotta be something in the tune.

 

[Ukfox89]

Have you contacted whoever you got the base tune from and see if they have any ideas? Unless something is really wrong with how you installed the fuel setup, then it sounds like it's gotta be something in the tune.

not yet, he isn't open until Tuesday, and im supposed to be taking the car down this weekend, id just like to get some miles on it before hand. that way we don't spend a ton of time on the dyno trying to fix stuff if theres anything that's going to be a problem

 

[ctgreddy]

I think he's deff gonna be the one you'll have to talk to. Hell if you didn't change the injectors/maf I'd try reloading the last tune you had and see what it does. just a switch to a return style system shouldn't need any huge tuning changes.

 

[Ukfox89]

well theres no FPDM hooked up and no FRPS to read from. so it might not like that too much

 

[Swervedriver]

Log O2 voltages, STFT, LTFT, Closed loop flag, Load, MAF counts, Fuel pressure, Spark source, Fuel source, Spark, Idle mode flag.

 

[03SonicVert]

well theres no FPDM hooked up and no FRPS to read from. so it might not like that too much

I think you hit the nail on the head. The computer is probably in some type of failure mode not being able to see FRP and control the fuel psi. It would be interesting to see what fuel inj duty cycle is at. The PCM would most likely default to a table established for MAF and TP to keep the engine running.

SV

 

[Ukfox89]

but surely if he sent me a start up tune with a return fuel system, all those tables woul dhave a 0 value so they wont be looking for the FRPS or FPDM. I can plug the FPDM in, but the switch 12v wire is no longer hooked up to it. the green with a strip I believe. and the FRPS I have, but sensor hits my fuel lines so I cant run it right now. coul dbe something to look into.

 

[Ukfox89]

just ran the CEL on my SCT, and it pulled a

P1000
P0193
P1233

so FPDM and FRPS, so im thinking the tune is still setup for returnless and the car is return now, so that would probably do it LOL.....ill contact tuner and try to get it squared away

 

[03SonicVert]

Frustrating but worth it in the end! I'm glad the codes point in a direction that should hold you over until you can get it to the tuner or emailed and load another.

Good luck! I was following your SC swap post and I'm sure there are quite a few out there interested in the end results.

SV

 

[Ukfox89]

Frustrating but worth it in the end! I'm glad the codes point in a direction that should hold you over until you can get it to the tuner or emailed and load another.

Good luck! I was following your SC swap post and I'm sure there are quite a few out there interested in the end results.

SV

yer I reall yneed to update that, I have been so busy with trying to finish the car and work. ill update and post some pics.

Thanks Ben

 

[ctgreddy]

Frustrating but worth it in the end! I'm glad the codes point in a direction that should hold you over until you can get it to the tuner or emailed and load another.

Good luck! I was following your SC swap post and I'm sure there are quite a few out there interested in the end results.

SV

x2 I cant wait to see some numbers from your setup man!