LS2 Fuel Pump

[hotrod52]

I put a 2006 LS2 in a 67 Chevelle and I am having problems losing fuel pressure at 5000 RPM and above. I had the stock computer reworked by Speartech and have the stock fuel pump relay in the system which is located in the dash area. My question is what size wire should I run back to the fuel pump in the gas tank. The wire on the fuel pump relay that supplies voltage to the fuel pump is a 20 gauge wire which seems very small to me.

Has anyone had this problem that can give me some input?

[BonzoHansen]

I dunno if that is your issue but here you have a 99Z28 that runs 22g (.35) and the guys with fast cars normally replace it with larger wire, like 10g. That may be overkill but I guess too big is better than too small.

http://repairguide.autozone.com/znet...3f8024bc8e.gif

[Ron S]

20 gauge does sound pretty light, but it sounds like under sizes fuel line, because of the dropping off at RPM's

[hotrod52]

I'm running 3/8 line for the feed and return, do you think thats big enough.

[CarlC]

What is the "stock" fuel pump?

3/8" is plenty big enough.

[Ron S]

3/8 is what I'm running in Mustang with no problems. I think I would run a 12 ga. cheater wire back to the pump,run it see what it does. If it still does it, it has to be the filter, pump, sock on the end of the pump, or the regulator.

[Mike Norris]

I would think that a larger wire would be better, but for a stock engine and pump, I would think you would have good pressure. Now if the engine is modified and making 600+ HP it could be an issue.

I would think it could be, as Ron metioned, some kind of restriction in the system or even a bad pump possibly. If you can check the voltage at the pump to see if it drops when the fuel pressure drops, that will tell a lot.

Mike Norris