Need Help choosing a Walbro 255 Pump

[Schmieder]

I need a fuel pump for my 96 Grand Prix SE 3100 Turbo 5-8 psi boost with 36 lb/hr injectors.

No FMU used, stock fuel pressure. Fueling increases are done through the PCM instead of fuel pressure boosting. So I don't need a high pressure pump, just high flowing.

I haven't ever had to fit a high flow pump instead of a stock pump, so please excuse my ignorance regarding.

I would like a Walbro 255 but not sure of the model needed.

This is what I had found so far. Would these pumps fit my vehicle?

Walbro GCA758-2
Walbro GSS307

If not, can anyone recommend a quality high flow fuel pump for my application?

Thanks

[robertisaar]

i'm not so sure if either of those are actually walboros...

but IIRC, a PFI fuel pump is generally the same between major changes (like the tuned port 85 camaro using the same pump as a 95 3100 wouldn't surprise me one bit).

[IsaacHayes]

Be wary of fakes.. .lots of them out there.

What is the p/n on your injectors BTW?

[WrathOfSocrus]

http://www.summitracing.com/parts/AC...Make|CHEVROLET

Looks like that one is listed for everything from 454's to 2.8's and smaller.

[robertisaar]

if you try to search by application, it seems that they list a lot of TBI or carb setups.... but i didn't find any port injected setups in my quick search.

[WrathOfSocrus]

http://www.summitracing.com/parts/ACF-EP378/

Sorry wrong part, if u do a search of in tank fuel pumps from ac delco there are a bunch listed. many of them cover a range of vehicles.

http://www.summitracing.com/parts/ACF-EP376/

That one is for LT1's such as in buick roadmasters. I'm sure they have other applications and brands that could be made to work as well.

[Weatheralls Auto]

http://www.racetronix.biz/itemdesc.asp?ic=FPA-007&eq=&Tp=

Modified for the venturi system.

[Schmieder]

Be wary of fakes.. .lots of them out there.

What is the p/n on your injectors BTW?

p/n idk. I have all my paper work/receipts in a box somewhere since the move.

They were from a supercharged 3800, iirc. Bosch injectors.

Fakes, yeah I heard about that trolling around forums.

http://www.summitracing.com/parts/AC...Make|CHEVROLET

Looks like that one is listed for everything from 454's to 2.8's and smaller.

Hmmm, not a bad price either. If it can fuel a n/a 7.4L, it should fuel a turbo 3.1L.

What about a new stock pump made by Bosch?

I'm going to try to find flow specs. Running only 5-8 psi boost, maybe that pump will hold up well enough. Opinions?

[IsaacHayes]

has to be a pump that is for fuel injection (port/multi/sfi) not TBI or carb, those run only like 7psi....

[Weatheralls Auto]

Does the 96 use a modular system with Venturi?

The link I posted uses Walbro pumps, but they are modified kits for the ventri fuel feeds.

[robertisaar]

has to be a pump that is for fuel injection (port/multi/sfi) not TBI or carb, those run only like 7psi....

pro-tip: pumps create flow, not pressure. that's the job of the FPR. if the pump can flow enough to create the pressure, it could work, unless there is some mechanical reason why it can't...

[IsaacHayes]

Right, but the TBI/Carb pump may be rated to flow 255 gph at 7psi of pressure (created by the FPR/carb resistance) but choke out if it encountered 55psi from the FPR... Likely due to mechanical design like you noted....

[3400beretta]

Does the 96 use a modular system with Venturi?

The link I posted uses Walbro pumps, but they are modified kits for the ventri fuel feeds.

I know in the berettas they all use the venturi system, however they have a removeable adapter with a small "T" fitting for the venturi feed. In other words, you can use a regular pump, and install the adapter from the OE pump, giving you use of your venturi setup. You do not need a special pump with a separate venturi feed on it.

[1988GTU]

Right, but the TBI/Carb pump may be rated to flow 255 gph at 7psi of pressure (created by the FPR/carb resistance) but choke out if it encountered 55psi from the FPR... Likely due to mechanical design like you noted....

That feed line would have to be awfully fat to flow that much at such low pressure.

[Schmieder]

Ok, I have a little time to figure out the pump fitment. I called summitracing and the tech recommended a BBK 1606. He said with minor modifications it will work well. He also said there isn't a pump that is designed to fit like OE that is a high flow.

So, I have some research to do.

I decided a new pump AND fpr is in order. I know one may be good over the other, but I want this car to run good for a while. I have so many new parts now, i should just do it. And if the problem still isn't resolved, I'll cross that bridge then. But all symptoms are pointing to a bad pump and/or bad FPR.

I guess sitting in the garage for 2.5 months wasn't healthy for the fuel system. Though I did add some seafoam per directions on can to the tank and crankcase and ran it to prime the system.

Now, I also have a thermostat question. What is the best temp thermostat for my application? 160, 180 or stock 195 degrees? I am thinking 180 because it is a little cooler but not too cool like the 160 is for extreme performance engines beyond my app.

Aside from altering the fan on/off temps, what other alterations would be required with a cooler thermostat? Should I adjust the various settings that are ECT dependent? Bear in mind I am seeking perfection but anything pointless is well, pointless, lol.