AkSSS

I'm willing to do that. I would rather make sure that is my problem before ordering a new pump. I have pretty much everything I would need. I can always pull my regulator off my truck. Unless you think a Home Depot air regulator would work. Might work for long enough for a test.

Atomic

iTrader: (42)

They work on the same principle, but it might be messier.

AkSSS

I have the battery out of my truck. I will put the battery charger on it when I test the pump, but I will run the wires from the battery straight to the pump. How do you test the voltage drop? Do you just read the voltage at the pump? That should stay constant as to what is coming from the battery right?

These pumps should hold pressure up to about 10psi right? What is your guess? I know my other pump is working fine at the 7psi. I'll know in a few hours. I am going to test it at lunch.

Atomic

iTrader: (42)

Yea, put your test leads at the + an - on the pump while its running. If its below 11.5 or so you have a wiring issue.

Btw, don't just dunk the pumps in a cooler of water, they will short out. Gasoline is a very good electrical insulator, water is pretty good conductor.

Hard to say exactly without knowing other details, but if your injectors are at 50% IDC a single 400 should not drop pressure until 20psi of boost with a 60psi base pressure.

AkSSS

Yeah, I won't use water. I have plenty of gas and meth sitting around. I played with the idea of just converting the truck over to straight meth. Should have done that from the get go.

My setup in second gear, it shifts at about 6600
-6518rpm
-152kpa
-18*
-11.15afr
-49% idc

Oh, and this is on 90 octane. That is our premium up here. That is the reason I run so much meth. I spray from about 8# and up. I run my waste gate at 7(or I am trying to), then flip my boost controller on and that energizes my meth setup also. This way my wife can still drive the truck too. She loves driving it, and I like keeping it turned down for her. HAHA

Atomic

iTrader: (42)

I doubt you want to run it on meth all the time. Meth is some nasty stuff, not really meant at all for a street vehicle. Good luck getting it to start in -40F weather also

Your injectors are 1000cc@3bar, right? A single 400 should take you to about 9-11psi or so before it starts dropping pressure. Right around 55% IDC.

AkSSS

Pretty amazing fuel. It takes a little while to get some heat in the sprint cars running straight meth! And I am lucky enough to not have to drive my truck in the winter any more. It sitting in the shop on jack stands. I am just getting started on working on it again. I've got a list of crap to do!

Yes, my injectors are 1k@3bar. So iirc they are like 112# or 118# at 60psi base pressure. That is where I am running it at.

I didn't end up having all the fittings I needed to bench test the pump. I am going to get everything this weekend. I will keep you posted.

Go5.3tt06

iTrader: (1)

perfect, I saw your trans cooler fitting/hose exactly that what I want. Can you give me info where I can get that hardware and hose brand. PM me the info. Thanks. Im running 4l80e like as yours.

AkSSS

I just went into my local hydrolics shop and took my cooler in with me to make sure I got the right fitting into the cooler

These are the fittings that I put in the trans.
http://m.summitracing.com/parts/TCI-831011

Then I got a 90* and a 45* fittin for the cooler, I think the 3/8 jic fittings? Then 15 ft of hose and two more 90's to go on the trans. All 6an line.

AkSSS

So, I had a hell of a time figuring out my bad pump issue. I tried setting up a little flow bench to test it. NOPE, its official. I'm no engineer.

I decided to take it to the local hydraulic shop and see if they could test it for me. They just so happen to have a pressure bench for testing their valves and stuff. So they just rigged up a 12volt power source and did a test on the fuel pump for me. These are the gph they gave me. They said there flow bench was probably not very accurate under 50psi, but they tried. They said their flow numbers are +/- 1gph.

Walbro 400
Test-all at 12volts
@30psi=~30gph
@40psi=~35gph
@50psi=~40gph
@60psi=~47gph
@70psi=~55gph
@80psi=~61gph

After looking online at the flow tables from Walbro, these are the numbers I should have. And I might be off 1 or two gph also. I use the table from this page. And my pumps are the F90000262.
Fuel Pump Pressure Charts

Flow Specs@12volts
@30psi=~22gph
@40psi=~32gph
@50psi=~43gph
@60psi=~52gph
@70psi=~60gph
@80psi=~72gph

So it looks like my pump does fine down low and as pressure increases the flow is dropping to fast for specs. Maybe I am reading this wrong but this is what I figured out. So, order new pump tomorrow.