Fuel Pressure

[ctrlraven]

After my little P0190 code yesterday and watching my scan gauge read 4% on fuel pressure I've been kind of iffy cause I'm suppose to race at the drag strip tonight.

On average what are NA fuel pressure ratings for idle, underload and WOT?

Mine are 25 for idle, 28-32 underload and saw the highest of 38 at WOT peak before the 1-2 shift.

[RacerX]

Hmmmmmm... Your fuel pressure should be @ 39 Idle and as close to 39 at all times except when coming off a WOT run you'll get a stacking effect and can see 60lbs which is fine. Something is off.

[babbage]

dont race with it like that!

[SC Cheesehead]

I'm around 30 lbs at idle and under light load, 40+ under acceleration, haven't really looked yet at WOT (have only really punched it a couple times and then I tend to get "preoccupied" with other things... :drive:), although I have noted a bounce off 60 as I'm decelerating.

[ctrlraven]

Let me take a look at the scan gauge xgauges again, I may be looking at the wrong thing.

I'm running stock fuel pump (reinstalled) and stock 24 lb injectors again.

http://www.scangauge.com/support/pdfs/XGAUGE.pdf

Which on page 4 should I be using?

[babbage]

Let me take a look at the scan gauge xgauges again, I may be looking at the wrong thing.

I'm running stock fuel pump (reinstalled) and stock 24 lb injectors again.

What codes did you use to setup x-gauge for FP? I love having my Trans Temp on the SG.

[babbage]

Let me take a look at the scan gauge xgauges again, I may be looking at the wrong thing.

I'm running stock fuel pump (reinstalled) and stock 24 lb injectors again.

http://www.scangauge.com/support/pdfs/XGAUGE.pdf

Which on page 4 should I be using?


Fuel Pressure (if no FPR) 616AF10123 044105230000 2810 000100570000 FP PSI


Did you add the fuel percentage by mistake? (e.g. How empty is my gas tank...? )

[RacerX]

Fuel Pressure (if no FPR). ? If no Fuel Pressure Regulator?? I'm not familiar with the scangauge.

[ctrlraven]

I was looking at the Fuel Pump Duty Cycle FP code under the Enhanced Data FORD PWM.

I have the Fuel Pressure (If no FPR) code installed but nothing reads on it.

I have a full tank of gas right now.

[babbage]

hmm. I'll try it. Duty Cycle isn't Fuel Pressure.

[RacerX]

If that's Duty Cycle, you should be fine!!! Are you sure it isn't .25, .35, etc.???

[ctrlraven]

It's def. duty cycle cause when I turn the key on it shows 75 and after I start it up at idle its 25.

I've tried several times in the past to get the fuel pressure code to work but never did. FPR on the default gauges shows nada and so does the Fuel Pressure (if no FPR) doesn't show anything either.

[ImpalaSlayer]

put a carb on it :lol:

[ctrlraven]

put a carb on it :lol:
Build me the adapter and I would. :lol:

[RacerX]

Hmmmm... It does sound like PSI. .5 is max for actual DC, different measurement though. Mine is @ 39psi at all times except when coming out of a run, you'll get you little ups and downs, but, no biggie. I don't have a good answer for you... What does it read if you pull the vacuum hose off the FRPS and plug the vac hose?
BTW!!! If you're seeing 38psi throughout WOT, You're good to go for a race!

[babbage]

Hmmmm... It does sound like PSI. .5 is max for actual DC, different measurement though. Mine is @ 39psi at all times except when coming out of a run

How are you measuring your PSI? Duty cycle of the fuel pump does not equate to fuel pressure, it just shows how busy the fuel pump is.

Perhaps your MAF needs cleaning? That's how the PCM knows how much fuel to add.

Raven: what version is your SG2? I had to send mine in for a "bios" update.

[RacerX]

No, mine's fine, it's his we're worrying about. Mine's between 38 to 40 stable and up to 60 on decel from wot. My fuel is A-OK! ;)

[babbage]

No, mine's fine, it's his we're worrying about. Mine's between 38 to 40 stable and up to 60 on decel from wot. My fuel is A-OK! ;)

yeah- I gather that! :rolleyes::D How are you (Racer X) measuring your Fuel Pressure. e.g how do you *know* you are at 39PSI?

[SC Cheesehead]

yeah- I gather that! :rolleyes::D How are you (Racer X) measuring your Fuel Pressure. e.g how do you *know* you are at 39PSI?

Prolly gauging it. I think he may have a ScanGauge, I'm using an AutoMeter for mine.

http://www.mercurymarauder.net/forums/attachment.php?attachmentid=24 036&d=1301761696

[musclemerc]

I was reading this thinking "how is reading PSI via the OBD2" ? I dont have PSI on my datalogger or on my SCT dashscan.

Let know this plays out Birdman.

[ImpalaSlayer]

done

http://www.sullivanperformance.com/yvs450/products/intakemanifold/intake4.6.htm

[musclemerc]

Those are nice, remember the ones Carcraft made to fit the 8 single barrel carbs?

[ImpalaSlayer]

Those are nice, remember the ones Carcraft made to fit the 8 single barrel carbs?


yeah, that company made cool stuff, sucks they closed up.

[babbage]

done

http://www.sullivanperformance.com/yvs450/products/intakemanifold/intake4.6.htm

heh! Nice. There you go Birdman! I double dare you. ;)


Prolly gauging it. I think he may have a ScanGauge, I'm using an AutoMeter for mine.

http://www.mercurymarauder.net/forums/attachment.php?attachmentid=24 036&d=1301761696
very nice - you ran a new line thru firewall with gromet and hooked up to what? Dave did you do this install?

Ugg. something else I'll want.

[musclemerc]

Good wrenchs know the guage runs to the fuel rail using a SS braided line Babbs. :P

There is a couple companies that make the FRPS adapater Trick Flow, Summit, SHMS, etc.

[LANDY]

I was reading this thinking "how is reading PSI via the OBD2" ? I dont have PSI on my datalogger or on my SCT dashscan.

Let know this plays out Birdman.I always have fuel pressure and fpdc on in my aeroforce. Its also easy to dattalog.

[RacerX]

??? Yeah, what he said^. You just add the "Pres Drop F Inj" pid in your SCT log parameters and it will log Fuel Rail pressure which is your injector pressure. Our PCMs call for 39.160psi @ the injectors. Here:
This is @ 51.125 because I was messing around with my KB BAP.

http://www.mercurymarauder.net/gallery/data/579/Datalog.jpg

[musclemerc]

I wonder how accurate that would be against a mechanical guage?

[ctrlraven]

How are you measuring your PSI? Duty cycle of the fuel pump does not equate to fuel pressure, it just shows how busy the fuel pump is.

Perhaps your MAF needs cleaning? That's how the PCM knows how much fuel to add.

Raven: what version is your SG2? I had to send mine in for a "bios" update.
I believe it is version 3.15.

[LANDY]

I wonder how accurate that would be against a mechanical guage? good question, the tuners go by it so is accurate enough.