I have a 09 Silverado with a 5.3 moded half way to the hills. As in cam, port polish, headers, etc. The truck shut down on me last week on the way home pulling a trailer with about 3 -4000lbs. It started sputtering and missing, then died. I was able to limb off the interstate to a local Chevy dealer ship in Clanton, Al. They told me that the truck has a bad fuel pump. Okay, makes since. They wouldn't work on it, o' well right. So I took it to my dealer ship in Huntsville, al and they are telling me a whole new story. They are telling that they can see a problem with the truck. They told me they can see the truck correcting the fuel trims constantly, and can hear and see the truck start idling horribly then die. So the customer rep told me that the reason the truck is doing that is because I deleted the cats and the two rear o2 sensors after the cats. I called BS on that. The truck has been that way for the past 15 to 20 thousand miles. The dealer ship in Clanton hooked a fuel pressure gage to the fuel rail and told me that the truck was under pressure, bellow 58psi and that when the gas cap is removed the pressure drops to 30psi and of course dies. What do y’all think? Fuel pump? Nothing has changed with the truck. Same tune for almost a year. The only thing I haven’t done was hook up the wide band to monitor the fuel ratio.

 

Have you hooked up a fuel pressure gauge and seen what its doin?

 

Clanton Chevrolet did. They are who told me that the fuel presure is less that 58psi and falls to 30 psi when the fuel cap is taken off.

 

I was just wondering if you did personally, I dont see why it would drop to 30psi when you remove the fuel cap.. That dont make sense.

 

Ya me too. I am going to buy one and tape it to the windshield while I'm driving it.