AdvAutoBob

Hey guys..

Been lurking a long time around here, and now have a question:

I've got a early 90's TBI truck in the shop with an LS1 (99 F-body), and after searching, couldn't find an answer...

I'm not getting sufficient fuel pressure (about 40 PSI or so), and need to know what pump to use with the OEM fuel sender in order to get the pressure up. From the look of it, a TPI pump was swapped in already, but it's not putting out anything near 58 lbs. The original LS fuel rail is in place with trucks return blocked off if this helps.

Thanks for any responses!

Robert

jay_lt4

iTrader: (4)

that pump is only designed to run about 15psi ,, you could swap to a pump for a tpi engine from a vette or f-body and get enough pressure to run it, you will need a regulator with a return line

oange ss

iTrader: (50)

use a replacement f-body pump or get an aftermarket version and replace the pump itself

ls1nova71

iTrader: (4)

How do you know a TPI pump was swapped in already? To look at them there is no real difference between a TBI and TPI pump. But a TPI pump will work if its regulated right. What regulator are you using? I'm running the Corvette FPR/filter with a TPI pump, got 11,000 miles on it with no problems.

LS1MCSS

iTrader: (18)

This pump will work.
http://cgi.ebay.com/ebaymotors/Walbr...QQcmdZViewItem

AdvAutoBob

TBI pumps usually put out 15-20psi max... we usually use those on old school carb conversions. The TPI pump (OEM style) usually puts out about 45-50psi maxed out, which is why I'm thinking the pump has already been swapped.

The FPR is the oem F-body regulator on the fuel rail crossover.


The more I think about it, the more likely I am just to use an inline pump and replace the fuel rail (to support future mods for the client).

Thanks for the replies...

oange ss

iTrader: (50)

that's not a regulator on the cross over, it's a pulse dampner, the regulator is part of the pump assembly

Carshopinc.com

iTrader: (5)

The F body regulator is in the tank, How are you returning fuel back to the tank on the truck? You should either convert to the system to a corvette fuel regulator combo or use a aeromotive regulator..... If all else fails you can do the walbro 255 pump...
http://aeromotive.carshopinc.com/pro..._id/3263/13109
I have the pumps in stock with -6 fittings for 132.95
http://i118.photobucket.com/albums/o...ogsl392008.jpg

AdvAutoBob

Ah... Thanks for the clarification (looked like a regulator to me).

Our shop is just now getting into LSx stuff, so excuse my ignorance... my area of expertise is a lot of "old school muscle" stuff and TPI/LTx.

AdvAutoBob

The return is blocked off (making it a "backyard returnless" system).. We've used Tsunami pumps (Aeromotive) on some of our LTx cars, so that's probably the way I'm going on this - replacing the fuel rail, adding the aformentioned FPR (our shop also sells Aeromotive, don't want to step on any toes here), using AN lines and making it a return style system.
I like to "overbuild" fuel systems a bit (makes room for future mods)


Thanks again for all the help guys!