I think I need a new fuel pump....

[Fitman]

1.90 best ever

 

[dynoman]

Did anyone else look at his powerlogger files ? The TPS numbers look like he is rolling into the throttle and only hits 4.3 once at the very end of the run . You need to check your TPS settings. .43 idle , 4.5+ WOT. Sam

 

[87GNSteve]

1.90 best ever

I think when you upgrade the fuel pump you will NOT see a drastic increase of performance. Its your 60 ft holding you back. Your race gas with alky is currently making up for the lack of fuel.
That being said I would most definitely upgrade the fuel pump and hot wire it. But your 60 ft is where the numbers are going to change big.
With a good fuel pump you will be able to run pump gas with alky and meet your expectations.

 

[Fitman]

Installed new Welbro 255 lph pump with Intermediate wiring kit tonight.
Can def tell a slight improvement in performance but only making 51 psi max of fuel pressure @ 27-29psi boost.....
I'm stumped!

 

[Gmoney]

You reset your TPS

 

[Fitman]

Sorry dumb question.....how do I reset my TPS?

 

[Gmoney]

Nothing dumb whatsoever! !
You got a scaaster?? Do you know where the TPS sensor is located?
Go to www.vortexbuick.com once your in click on HOW TO's and itll walk you through the steps!!

 

[Fitman]

I'll give it a try tomorrow morning.
Thanks Gmoney!

 

[Gmoney]

ANYTIME!! vortex buick has a wealth of other info sift through it big guy!!

 

[dynoman]

only making 51 psi max of fuel pressure @ 27-29psi boost.....
I'm stumped!

Did you check base fuel pressure after the pump change ? If base FP is ok , check for cracks or loose connections anywhere on the length of vacuum reference hose to your fuel pressure regulator . Also get another known good gauge to check the one you have now . I had one that read 9 psi low and it cost me a head gasket . Test your regulator & pump by doing what fastblackracing said to do in post#2 with both gauges , you could have a bad regulator .

 

[DeltaBravo]

Yes idealy you should be seeing 71 psi. Usually when a fuel system cannot keep up the pressure will start of closer to the target pressure and will drop as rpms and injector duty cycle % goes up......as the system cant supply the required volume to maintain the pressure target.

This is exactly what mine does...I am curious if you have found the problem. Any updates?

 

[Fitman]

DeltaBravo is your question regarding my overall issue with results not equating to all my performance upgrades? or just my fuel pump psi issue?

 

[DeltaBravo]

Hi Fitman,

Well...not sure, but I though they were related...

Isn't the fuel issue possibly hurting your overall performance? Either way, I have a similar problem. I run 20psi on boost and my fuel pressure gauge reads about 40psi at idle and when I get on it, pedal to the floor, the fuel pressure will initially match the 20psi boost and increase up to 60...but as soon as it get there, it quickly drops to about 50-54'ish and holds there. I don't get any knock but my milv are anywhere from low 600's to mid 700's, which from what I understand is a direct correlation to how 'lean' I am running. It should be mid to high 800's.

Because of this and the fact I have no know history of the current fuel pump I currently have, I'm thinking I have a fuel pump issue.

So I was wondering if you discovered what was causing your similar issue. Pump, volts, ground, regulator....???

Thanks,

 

[dynoman]

Hi Fitman,

Well...not sure, but I though they were related...

Isn't the fuel issue possibly hurting your overall performance? Either way, I have a similar problem. I run 20psi on boost and my fuel pressure gauge reads about 40psi at idle and when I get on it, pedal to the floor, the fuel pressure will initially match the 20psi boost and increase up to 60...but as soon as it get there, it quickly drops to about 50-54'ish and holds there. I don't get any knock but my milv are anywhere from low 600's to mid 700's, which from what I understand is a direct correlation to how 'lean' I am running. It should be mid to high 800's.

Because of this and the fact I have no know history of the current fuel pump I currently have, I'm thinking I have a fuel pump issue.

So I was wondering if you discovered what was causing your similar issue. Pump, volts, ground, regulator....???

Thanks,

Is your pump hot wired ? If it is , it sounds like the pump can't keep up and could be time to upgrade it . First , if it isn't hot wired , please do that first and then check pump by supplying a regulated air pressure supply to the fuel pressure regulators vac/boost port to simulate boost pressure . When you put 20 psi to that port with the pump turn on , the fuel pressure should rise from what ever your base pressure is , say 42 psi + 20 psi = 62 psi , and hold there as long as 20 psi is applied and not drop off . If it does drop off it's time to drop the tank check all connections ( electrical & in tank hoses ) . If all connections & in tank hoses are good , change the pump .
Almost forgot , how old is the fuel filter ? If you don't know ..... change it . Good Luck , Sam

 

[DeltaBravo]

Is your pump hot wired ? If it is , it sounds like the pump can't keep up and could be time to upgrade it . First , if it isn't hot wired , please do that first and then check pump by supplying a regulated air pressure supply to the fuel pressure regulators vac/boost port to simulate boost pressure . When you put 20 psi to that port with the pump turn on , the fuel pressure should rise from what ever your base pressure is , say 42 psi + 20 psi = 62 psi , and hold there as long as 20 psi is applied and not drop off . If it does drop off it's time to drop the tank check all connections ( electrical & in tank hoses ) . If all connections & in tank hoses are good , change the pump .
Almost forgot , how old is the fuel filter ? If you don't know ..... change it . Good Luck , Sam

It's hot wired. And my fuel filter is new...maybe 500 miles on it.

So I'm thinking is a fuel pump issue. Thanks for the insight.

oh...and I didn't mean to highjack this thread. I'm still curious if Fitman found a solution to his problem.

 

[dank GN]

Get a walbro 430 hot wired and you shouldn't have to touch your pump for a long while . Some 60lbs injectors , and READ ,READ ,READ as stated before there is a wealth of basic GN knowledge at vortex Buick . Good luck and happy boostin !!