3800 Fuel Pump vs Fuel Trims

[MIKES3]

I already posted this in the GM V6 forums but I wanted to hear input from some of you guys in here.

I dont know if my fuel pump should be replaced, but I am having on hell of a time tuning in my fuel trims. Can a old fuel pump or one that has a lot of miles on it effect fuel trims?

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[Sinister Drag Designs]

test the pump

 

[SaturdaysGS]

I THINK I read on ClubGP that a guy with an 04' was having problems keeping steady fuel pressure. The car would start fine and the fuel pressure would be A-OK, but then a little while later (10 seconds?) pressure would change, and it would never stay at a steady pressure. I couldnt find the thread, and I can't remember any more details but maybe throw up a post there and see.

 

[smug]

Originally posted by MIKES3@Oct 1 2006, 03:27 PM
I already posted this in the GM V6 forums but I wanted to hear input from some of you guys in here.

I dont know if my fuel pump should be replaced, but I am having on hell of a time tuning in my fuel trims. Can a old fuel pump or one that has a lot of miles on it effect fuel trims?

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Yea a fuel pump with a lot of miles can cause odd thing to happen with fueling. Do you happen to have the zzp rewire kit? I would recomend you get this too. If your pump has a lot of miles on it or it is dieing then when you are at WOT your O2's will be ok and then drop the longer you are you WOT. My car has 72,000 miles and my O2's were dropping a little when going WOT and I installed the rewire kit this week and now they are not dropping anymore at all. This goes to show how crappy the stock wiring is and how critical a good fuel pump it too.