im new to the forum, any help will be appreciated. I own a 1994 3/4 ton 4x4 suburban with 454 TBI. i installed new crate motor 2 years ago, its got about 50k miles on the motor and new tranny. my sub was running fine and all of a sudden shut off, towed it home ,I started it the next day then after about 10 minutes it started sputtering ,injectors were delivering more fuel than usual.it would not idle and then eventually die, I cannot raise rpms ,sometimes it backfires inthe throttle body.
i replaced plugs,wires,cap and rotor, and fuel filter. started ran better and after 30 min it started doing the same crap. I installed fuel pressure gauge before fuel filter to check psi .key on engine off 35psi ,and key on engine on 35psi, then when i shut off it instantly goes to 0psi does not hold pressure.I removed tbody and inspected pressure reg,eveything was fine exept that fuel return hose seemed resistant to flow ,I used airline to blow into return line ,still think this is my prob.installed everything back ,still runs rich!! Im will be cleaning my IACV ,checking tps,Map,Temp sensors,I know my fuel pressure should be 12 to 15psi, thats why I think it is a kinked hose or something in the return line, by the way gas tank is venting properly and canister purge is fine. am i way off ? can anyone shed some light?i will be checking egr valve but im trying to keep it simple for now.
i replaced plugs,wires,cap and rotor, and fuel filter. started ran better and after 30 min it started doing the same crap. I installed fuel pressure gauge before fuel filter to check psi .key on engine off 35psi ,and key on engine on 35psi, then when i shut off it instantly goes to 0psi does not hold pressure.I removed tbody and inspected pressure reg,eveything was fine exept that fuel return hose seemed resistant to flow ,I used airline to blow into return line ,still think this is my prob.installed everything back ,still runs rich!! Im will be cleaning my IACV ,checking tps,Map,Temp sensors,I know my fuel pressure should be 12 to 15psi, thats why I think it is a kinked hose or something in the return line, by the way gas tank is venting properly and canister purge is fine. am i way off ? can anyone shed some light?i will be checking egr valve but im trying to keep it simple for now.