Fuel psi not going 1:1

[KEVINS]

I don't know if I should ask this or not but I will anyway.

How many people do NOT have their fuel psi rising at a 1:1 scale with boost??? ANYONE?

Within the last two weeks I have installed a brand new DW300 and new wiring (YES! I have good voltage), brand new AC Delco fuel filter, Billet fuel regulator, replaced and wire tied all the small boost/vacuum hoses.
With all this: last week with 42.5 injectors and matching alchy chip I was able to get the boost/fuel psi to come within 1-2 psi of each other at 26psi of boost and this dropped the inj. duty cycle from 117 to 95%.

Today I switched to 60lb Inj and matching TT chip and hooked up the stock PCV and now at 30psi of boost fuel psi is only going to 63psi! Injector DC is saving my ass right now at 78% (O2's at 780).

How absolutely critical is this 1:1 rise in fuel psi if the injectors and O2's are safe??

Note: There are several things that I'm still going to try like plugging the PCV back up, etc to get it back to where it was..

ks

 

[Phoneguy]

That pump should be more than enough...what is your base pressure? Which billet regulator?

Bryan

 

[rmar]

If you are going to run 30 psi very long .....Get a wide band. Recheck your gauge
If you are not getting any knock.

 

[KEVINS]

That pump should be more than enough...what is your base pressure? Which billet regulator?

Bryan

Yea I know. There has to be a boost leak at the FP regulator or ?? but I've done everything I can possibly think of to eliminate ANY small leak. My next step is to plug the PCV valve b/c other than the new injectors this is the ONLY thing I changed. I did not even remove any hoses b/c I was afraid this could happen. I'm also going to install a new gasket under the vacuum block with a very light film of silicone to assure it's not leaking although there already is a new gasket and film of silicone.

Base FP is 43 vacuum line off according to the brand new AEM transducer and Powerlogger along with the brand new xdcr reading the boost.

Billet Regulator is the one from Kirbans.

Does your fuel psi rise at an exact 1:1 or is it off a little, like 1psi?

ks

 

[KEVINS]

If you are going to run 30 psi very long .....Get a wide band.

LOL.. Thnx, I know, I know, but that won't help my fuel psi any.. One thing at a time...

ks

 

[Phoneguy]

I really cant give you an answer about mine......it seems that my car would rather sit than run, been like that for 5 years !!

Bryan

 

[Phoneguy]

1-2 psi off would not worry me

Bryan

 

[rmar]

Mine comes up real close to 1:1, but beside the usual suspects, check the gauge. Sounds like ya got the fuel.
Are you seeing it on the mechanical gauge , or from the power logger w/ transducer?

 

[KEVINS]

Mine comes up real close to 1:1, but beside the usual suspects, check the gauge. Sounds like ya got the fuel.
Are you seeing it on the mechanical gauge , or from the power logger w/ transducer?

Boost and fuel are monitored in PL and xdcr's.

ks

 

[forcefed3.8's]

I had a car running at 16.7:1 AFR on a wideband and the narrowband showed .810!!!!!!! Get a wideband. You are 10psi lower than it should be, you are lean for sure.
I doubt you are making "stupid power" at these boost levels. The compressor wheel will make the boost, but you are still running an old school T31 turbine that is done at 120mph or so, which a TA49@28psi will do.

 

[KEVINS]

I had a car running at 16.7:1 AFR on a wideband and the narrowband showed .810!!!!!!! Get a wideband. You are 10psi lower than it should be, you are lean for sure.
I doubt you are making "stupid power" at these boost levels. The compressor wheel will make the boost, but you are still running an old school T31 turbine that is done at 120mph or so, which a TA49@28psi will do.

If it was that lean the knock detector would be screaming at me and I would need to have the achy spraying a lot to eliminate it but it's still at the stock setting. I trust and listen for the knock detector more than anything and so far it matches what PL is telling me.

Remember, "Stupid Power" is a matter of ones opinion. Anything more than my 6cyl Maverick is stupid power, IMO. Besides I like playing with my sig for my own entertainment.

ks

 

[forcefed3.8's]

The car had alky and showed no knock!!!!!!! 3 months later it had 2 blown headgaskets, all main bearings were toast, the crank was junk, and a thin spot in # 5 cylinder was cracking.

 

[KEVINS]

Geeezz.... Calm down!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! LOL
Sounds more like you needed a better knock detector if it didn't show any but it was knocking enough to cause that much damage..

ks

 

[forcefed3.8's]

Put 30psi shop air pressure to the regulator to determine if it rises properly at idle, or hotwire the pump to run with the car off. This will rule out the regulator. If it rises 30psi under low demand, then something is wrong with the pump.

 

[Chuck Leeper]

Boost and fuel are monitored in PL and xdcr's.

ks

A couple things:
1. I've tested several gauges on a comparo w/ the inj bench gauge..They have shown as much as 7# difference. [The little silver dollar size proved to be the worst.]
2. I've tested several transducers the same way..Some don't come close. [They went back to Autometer.]
3. I've seen liquid filled gauges go whacko when they get exposed to under hood heat.

If I was doing the chasing, I'd look at the in-tank hose connection. [Just fixed one such issue. The hose was on, but the clamps not tite. Psi went to 43, steady. Should have been 60.]

 

[Pronto]

Do a vacuum test on the regulator. I had a leaks around the threads.

 

[KEVINS]

Great ideas, guys!
I would not have thought to do a leak test on the regulator!

ks