Lift pump part number question

[Spindrift]

It's time for a new lift pump. I've heard that there are two pumps on the market. Most things exactly the same: current draw, price, fittings, plug-in. Except for pressure. One pump is rated for 6-8 psi while the other is rated for 10-14 psi. Anyone know if this is correct? Part numbers were E3158 and E3309 thru NAPA.

If this is true, wouldn't the pump with the higher pressure rating be the way to go?

Contradictory information now. Apparently the vehicles with the "F" have only one pump available. Of course, it's the more expensive one at $120.

[ 10-21-2004, 08:58 AM: Message edited by: Spindrift ]

[JohnC]

I think the 6-8 psi pump meets the specs for the EFI trucks.

In this case I don't think "more" is any better. The pump housing has a pressure relief valve set around 6 psi, so a 10 psi pump would be beating itself up trying to produce 10 psi. I think a pump with greater volume capability might help since the pressure seems to drop under full throttle, but more pressure is not going to help that either.

[ 10-21-2004, 01:31 PM: Message edited by: JohnC ]

[steve-r]

i bought the 10-14 psi LP from Napa. other members haved advised it was fine. my theory is more is better, since IMO the LP is one of the weaker components of an already feeble fuel system.

[Kennedy]

I pretty much only stock the higher psi unit. I also stick to AC Delco as the best brand going for these.

[Dihrdbowti]

While doing a search with those two part numbers against ACDelco I found that the E3158 or ACDelco# EP158 is for 94-98 vehicles while the E3309 or ACDelco# EP309 is for 86-93 vehicles. When you do a search on Napaonline.com using the ACDeclo#'s I found that EP158 show the PSI as 10-14 and 20 gallons per hour but that it has two different pumps @ $66 and the other at $77. While the EP309 is around $100 it is rated at 10-15 psi and 32 gallons per hour. Prices and participation may vary. :D

[JohnC]

Since th higher pressure pump can never reach pressure nirvana, it will end up being flow limited. This might be a good thing as more fuel will be circulated through the pump housing and the pump will be (maybe) more effectively cooled. Guess it can't hurt...