Fuel pressure

kitttransam · September 14, 2015

I wanted to verify what fuel pressure my truck should run at. My 99 Silverado 2500 6.0 has been bogging at moderate throttle at high speed and idle is randomly dropping when a/c is running. Already hooked to a scanner and everything looked good. No misfires or any other things showing up. My fuel pressure measured 50 psi running and 54 psi with just the key on. I read it should be in the 60's but wanted to make sure. Any suggestions on brand of fuel pump? Heard it's a crap shoot to get a good one no matter which one I get.

00Silverado4x4 · October 5, 2015

Have you checked the fuel pressure regulator? You pop the vacuum hose off the top of it and if you see fuel, it will need to be replaced. The regulator is on top of the engine, driver side above the fuel rail.

newdude · September 14, 2015

Key on engine off you should be at 55-62psi. It should drop no more than 5 psi in a 10 minute time frame. There is a fuel pressure regulator at the fuel rail so that is a possibility. Also, a fuel filter would be a good thing to change if it hasn't been. If you really like the truck and want to keep it for a long time, I'd go GM/AC Delco on the pump. If you dump it in a year or two, there are others that are cheaper. I'd stay away from Airtex. My friend got 2 months out of one on his gf's 1998 Jimmy.

kitttransam · September 14, 2015

Fuel filter isn't that old just changed about a month ago. No fuel came out of the regulator when I tooked the hose off so I assume it's still good. Yeah I plan on keeping my truck so I'll go for the best I can get. My truck has over 200k on it so I really think it could be the pump.

kitttransam · October 4, 2015

Well just an update. I got the truck back together. After I soaked my injectors in seafoam. Idled smoother initially. But was still bogging out at half to full throttle. Went a little nuts and put seafoam and Lucas additive in the gas tank. And ran seafoam through the intake. After 2 days and romping on the throttle I don't notice anymore hesitation.

kitttransam · September 25, 2015

so I replaced the fuel pump and guess what . wasted $157 on a new delco pump. problem still there. so went into diagnosing mode and started looking at other possibilities. So found out the new fram fuel filter came apart inside the housing. replaced that with a wix. even had made in usa stamped on it. but problem still there. so figured some crud got in the fuel system. found 2 injectors with crud in the top injector baskets. took some pics not sure how good you can see.