5.3 swap from old truck to new truck and wont run now

[hubdawg]

Took the 5.3 out of my 72 k10 and put it into my 72 k5 and now it wont run worth a crap. Inline fuel pump from prior rig with 54lbs pressure and had a friend run obd with no codes. He ran a test on the maf and it was super high and smelled rich. Barely runs and backfires and have to pump throttle but when I unplugged the maf , it starts but then run to super high rpm's so I shut it off. The rear vacuum connection on the intake to power booster was suspect but doesn't appear to be leaking air. New maf needed or is that just shotgunning parts? Maf has 12v to it and good ground. Any ideas?

[carkrazy1987]

if you unplugged the maf and the rpm jumped, i would say you have a vacuum leak. how long did you run it with maf plugged in, codes may have not set right away. return style fuel system? hoses hooked up backwards? when you swapped the engine, did you remove the intake? did you transfer the harness with the engine? forget a ground on the main harness? one on back of head. going to need abit more info on the swap.

[hubdawg]

Wouldn't stay running with the maf plugged in and I want to say the maf reading was like for a 9L engine. Set the fuel lines up exactly like before so I don't think that is part of it. I never removed the intake and the harness and tranny were all removed and replaced in the new frame. I have a ground on the computer to the body and block to the body. When I try to start with the maf connected it misses and wont run. When I unplug the maf and try to start it runs but then goes to high rpm's and I have to turn it off. Should I try and seal that back intake to power brake boost. Is the a way to check for vacuum leaks with an engine that won't run long enough?

[hubdawg]

I think I'll try re-grounding everything, I think I fixed the vacuum leak from the back of the brake booster push lock connection on the intake. No runs rough still but only for a few seconds then dies, still smells super rich. At least it doesn't run to high rpm's and have to shut it off anymore. I'm hoping that's progess