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**kev2809** · 01-23-2023, 10:33 AM

hate to clog up the boards with another thread, but I'd figure I would get more traffic here than my build thread.

let me start from the beginning. truck has fired up great since I first tried it a few months ago. haven't left my driveway for a run, but started and idled fine. I did my exhaust setup by myself, welding in 2 flowmaster fx mufflers in and dumped the pipes after the TA Xmember. I left the 02 sensors in while welding. I installed everything and connected the battery. truck wouldn't crank first try, but did second time. it would stumble and hesitate over and over. I bought new 02 sensors thinking I fried the others.. same issue with the new ones. finally after a bunch of start ups it finally idles nice and doesn't cut off.

but now it's throwing p0102 code, which is low voltage to MAF. I checked the power and ground wires with key on for the MAF plug and they both are reading 12 volt.. ish. when I try to take it for a spin, it bogs down and nearly shuts off and backfires a little when u give it a little pedal in gear. so, I swap in a new MAF, same problem.

I then rent a fuel pressure gauge, I'm getting 15 psi at the rail! running or just key on, it's 15. so I check the stock fuel regulator by pulling the vac line and there's no fuel, which is good. however, when I pull the vac line while the truck is running, the fuel pressure doesnt move at all, stays 15 psi. I know the gauge works, I tested it on my 2002 avalanche with a 5.3 and it shot up to 55-60

I did pull of the fuel line at the rail and turned the key on a few times to cycle fuel to maybe push out any clog, but I didn't see any.

so, maybe my entire issue is the damn fuel pressure. it has a new stock style fuel filter (I did order a K&N that I will try for the hell of it), new acdelco ep381 fuel pump (listed for a 1997 Tahoe). all new AN hoses. I will pull the sending unit today and see if maybe the pump hose is damaged? or maybe the screen fell off?

wether it's related to the MAF code or not, I need to solve this fuel pressure issue.

01-23-2023, 10:33 AM	#1
kev2809 low n' slo Join Date: Mar 2009 Location: rosenberg, texas Posts: 5,134	Swap pros, need advice hate to clog up the boards with another thread, but I'd figure I would get more traffic here than my build thread. let me start from the beginning. truck has fired up great since I first tried it a few months ago. haven't left my driveway for a run, but started and idled fine. I did my exhaust setup by myself, welding in 2 flowmaster fx mufflers in and dumped the pipes after the TA Xmember. I left the 02 sensors in while welding. I installed everything and connected the battery. truck wouldn't crank first try, but did second time. it would stumble and hesitate over and over. I bought new 02 sensors thinking I fried the others.. same issue with the new ones. finally after a bunch of start ups it finally idles nice and doesn't cut off. but now it's throwing p0102 code, which is low voltage to MAF. I checked the power and ground wires with key on for the MAF plug and they both are reading 12 volt.. ish. when I try to take it for a spin, it bogs down and nearly shuts off and backfires a little when u give it a little pedal in gear. so, I swap in a new MAF, same problem. I then rent a fuel pressure gauge, I'm getting 15 psi at the rail! running or just key on, it's 15. so I check the stock fuel regulator by pulling the vac line and there's no fuel, which is good. however, when I pull the vac line while the truck is running, the fuel pressure doesnt move at all, stays 15 psi. I know the gauge works, I tested it on my 2002 avalanche with a 5.3 and it shot up to 55-60 I did pull of the fuel line at the rail and turned the key on a few times to cycle fuel to maybe push out any clog, but I didn't see any. so, maybe my entire issue is the damn fuel pressure. it has a new stock style fuel filter (I did order a K&N that I will try for the hell of it), new acdelco ep381 fuel pump (listed for a 1997 Tahoe). all new AN hoses. I will pull the sending unit today and see if maybe the pump hose is damaged? or maybe the screen fell off? wether it's related to the MAF code or not, I need to solve this fuel pressure issue. Attached Images __________________ 67 1/2 ton Suburban - Project DRGNWGN. Build thread -_--_--_ _________ _--_-_ -/____\|__\|__\__ ,.,,,.,.,,.,\|_O _______ O_]