swapped 3.1 to 350 carb 91 rs
Thread Starter
Member
Joined: Jul 2004
Posts: 115
Likes: 0
From: illinois
Car: 1982 z28
Engine: 350
Transmission: th350
swapped 3.1 to 350 carb 91 rs
i did the swap and everything seemed to be fine until it died from lack of fuel i can see this in the glass. i turn the key on it fills up and i can start it and go for a mile then it dies. i ran the fuel line directly to the fuel pump on the block, same thing, ieven had um both working ,the same crap, whats up fellas
Joined: Mar 2000
Posts: 43,187
Likes: 43
From: Littleton, CO USA
Car: 82 Berlinetta/57 Bel Air
Engine: L92/LQ4 (both w/4" stroke)
Transmission: 4L80E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
Originally posted by dmp7777777
i turn the key on it fills up and i can start it ...
i turn the key on it fills up and i can start it ...
You need to use an oil pressure switch to keep the electric running after the engine starts. What's happening is the timed relay is allowing the pump to start when you turn on the ignition, but as designed it shuts off a few seconds later. The mechanical on the engine isn't able to suck hard enough through the non-running electric and keep up.
You should also have a regulator in there (after the mechanical would be fine), the type of reg that uses a return line. The electric will be the "pusher", and the mechanical the final pressure up to the carb.
Last edited by five7kid; Jul 23, 2004 at 07:24 PM.
Supreme Member
Joined: Nov 2003
Posts: 1,965
Likes: 0
From: Philly
Car: 85 firebird
Engine: Pos 2.8 pulled and replaced with a 350 tpi motor converted to carb.
Transmission: 700r4, vette servo,shift kit, hayden 15"x8" trans cooler.
Re: Re: swapped 3.1 to 350 carb 91 rs
Originally posted by five7kid
Sounds to me like the electric is still in there.
You need to use an oil pressure switch to keep the electric running after the engine starts. What's happening is the timed relay is allowing the pump to start when you turn on the ignition, but as designed it shuts off a few seconds later. The mechanical on the engine isn't able to suck hard enough through the non-running electric and keep up.
You should also have a regulator in there (after the mechanical would be fine), the type of reg that uses a return line. The electric will be the "pusher", and the mechanical the final pressure up to the carb.
Sounds to me like the electric is still in there.
You need to use an oil pressure switch to keep the electric running after the engine starts. What's happening is the timed relay is allowing the pump to start when you turn on the ignition, but as designed it shuts off a few seconds later. The mechanical on the engine isn't able to suck hard enough through the non-running electric and keep up.
You should also have a regulator in there (after the mechanical would be fine), the type of reg that uses a return line. The electric will be the "pusher", and the mechanical the final pressure up to the carb.
When we put my motor in i wired the fuel pump to the ops on the v8. Never had a problem with the fuel pump. 
Thread
Thread Starter
Forum
Replies
Last Post
theshackle
Tech / General Engine
4
Sep 17, 2020 08:26 AM
theshackle
Tech / General Engine
4
Mar 5, 2017 06:37 PM
