fuel pressure problem real vs. frps

[v8tiger]

I have an 04 cobra with the usual mods. Pulley port exhaust intake. BAP after fpdm

And a local tuner has tuned it. A couple weeks after it was tuned I started getting a p0190 code. Well after looking at the logs fuel pressure was dropping to 14-19 psi during a 2nd or 3rd gear pull. After getting it on the dyno after seeing this. Car made 50 less wheel hp and was at 10.0 afr. It was tuned at 11.3. So we hooked a actual fuel gauge to the schrader valve and during the pull it stayed at 40psi while in the datalog showed 14-19
.

Ok ok so I figures bad frps. Got a new one from ford and the kb disc. Put it in, 5 miles down the road I do a pull and its the same.

Car has 10k miles on it. So I doubt there is a issue with the wiring.

Anyone have this problem or know anything to do?

 

[v8tiger]

TTT

anyone?

 

[SVT_Troy]

Man it has seemed slow around here lately....wish i could help you out..... how are you data logging exactly?

 

[earico]

If u search there are plenty of threads that say the BAP should be BEFORE the fpdm. I would start there.

 

[v8tiger]

I'm using a Sct handheld

If you search a lot of people say do it after too

 

[SVT_Troy]

oh im not saying anything is wrong with it at all, just curious how you were logging. Im using the innovative LC-1 through my sct myself

 

[earico]

I'm using a Sct handheld

If you search a lot of people say do it after too

The way I understand it is that if you run it after the fpdm you have to have a modified fpdm because it will overload a stock one and fry it because the BAP will draw too much current thru the fpdm.

If you run it before the fpdm then you can use a stock fpdm. I also believe that the current KB instructions say to install it before (with wire upgrade).

Maybe someone will chime in and verify.

 

[v8tiger]

TTT

anyone else?

 

[1wild-horse]

verify VREF circuit at the frp sensor connector. Should be the Brown/white wire. Check it for 5 volts. back probe it if you can, carefully.
3volts plugged in key on eng. off. 5 volts unplugged

 

[v8tiger]

Yup it is.

 

[1wild-horse]

signal return wire o.k.?

 

[v8tiger]

all wires from frps are ok.

 

[03mustang92]

anything ever get figured out?

 

[TVSCobra]

First you need to wire the BAP before the FPDM wire the hobbs switch together and wire the dial together. Then get it tuned.

 

[v8tiger]

Nope, its winter. Ordered Gt pumps.

Thinking lack of fuel volume.