TBI to carb....

[SUBFAN]

Help me make a list of things to change over.

For my '90 'Burb....I am contemplating a stroked Pontiac or a 420" sbc. I don't like the idea of chip burning and such. I want to keep it simple and cheap, using parts I have already gathered....

For you FI lovers, my carbed '77 used to be the one on the block that ran around and jump started all the FI cars....

 

[tiger9297]

I have a '90 K5 and I'm looking to remove stock engine w/ a new one. I have thought about going w/ a carb. but i don't want to have to disable all of the computer junk, as my truck is basically in like new condition. If there is a way to do it I'd love to hear about it. You could just go with a bigger TBI and manifold. You can get a 750 cfm TBI. I think the stock one is 450 cfm. Just a suggestion. I would be very interested to know what you decide.

 

[shaun]

I am in the process of doing this. I was just going to swap a carb onto my truck but it ends up being not that simple. Once you remove the injectors (throttle body) you have to run a power sw to your pump (or wire it to your ignition). Then you have to put in a pressure regulator. I assume you would eliminate the ecm which I was. This will eliminate the ICM which means no power to the coil so no spark. Meaning you will have to swap in a new distributor, coil and do some wiring or simply run voltage to your present coil. These were just some of the things to do.

So I said f it and am ripping out my tbi 350 and wiring harness complete. I am putting in the gm 18 circuit painless wiring kit with a carbed 402 and will use that until I can afford marine fuel injection for the 402.

 

[SUBFAN]

Since I am not big on wiring, the elimination of as many as possible would be sweet. All that crap just burns my a$$ being in the way.

biggest reasons for thinking about switching back, is simplicity and cost involved with getting more air fuel into it, not even counting the chip /forums/images/graemlins/thinking.gif

 

[SUBFAN]

Does the computer need to 'see' oil pressure? '90 TBI motor....

 

[dyeager535]

It needs it for the fuel pump wiring, thats it. (if the fuel pump relay fails, once the oil pressure switch sees approx. 5 psi, it will turn the pump on)

I thought a '90 would already be setup this way, but around that vintage cars and trucks went to a combination pressure switch/sender that is smaller than the earlier truck oil pressure sender. Run all three wires to the same one. Much cleaner IMO.

 

[shaun]

If the computer does not see oil pressure it will cut the signal to the fuel pump. This is a safety feature to prevent you from blowing your engine by running it with no fuel. I am pretty sure that is how it works.

 

[RootBreaker]

[ QUOTE ]
If the computer does not see oil pressure it will cut the signal to the fuel pump. This is a safety feature to prevent you from blowing your engine by running it with no fuel. I am pretty sure that is how it works.

[/ QUOTE ]

that is why when I put a 1991 caprice police motor in my truck I went from TBI to Carb.. I like my truck so stupid... /forums/images/graemlins/waytogo.gif

 

[SUBFAN]

[ QUOTE ]
[ QUOTE ]
If the computer does not see oil pressure it will cut the signal to the fuel pump. This is a safety feature to prevent you from blowing your engine by running it with no fuel. I am pretty sure that is how it works.

[/ QUOTE ]

that is why when I put a 1991 caprice police motor in my truck I went from TBI to Carb.. I like my truck so stupid... /forums/images/graemlins/waytogo.gif

[/ QUOTE ]



EXACTLY..... /forums/images/graemlins/waytogo.gif /forums/images/graemlins/bow.gif /forums/images/graemlins/waytogo.gif /forums/images/graemlins/thinking.gif