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sgp0511 01-03-2015 04:40 PM

what to do, tbi or carb
so im in the process of pulling the 350 tbi in my 88 firebird. Car is originally a 305 car, but i got the car with the 350 in it. the reason im pulling is because motor is bad. I got a 305 in good condition for free. the 305 has a quadrajet electronic carb on it right now. I want to do this without having to spend to much, so im stuck between using the tbi from the 350 in the car now and just getting an hei and new carb and running it like that. Im not too familiar with tbi, as i do not know what sensors i will need for the tbi to run correctly. the setup on the car right now has everything, was supposedly a good running car before engine went. im thinking just swap intakes and run tbi since in basically have everything already. only thing that worries me is if it doesnt run right i wont know where to even start on a tbi car. a carb on the other hand im ok with as my daily driver right now is a mopar with a 318 and a 2 barell carb. any input is appreciated

RFmaster 01-03-2015 05:15 PM

Re: what to do, tbi or carb
Go with TBI - it is easy swap and long term drvivability will be better. Depending on the area that you live in swapping in carb is illegal. It is a big no-no in Kalifornia.

You'll need to pull QJET intake and swap in TBI intake. The 305 injectors will need to be sourced - they are very common at local pick your part yards. By switching to 305 injectors (50 lb/Hr green/white) you can avoid changing EPROMs in your ECM. I also suspect that your ECM still has original 305 calibration EPROM. All other sensors can be swapped over from 350 onto 305. Depending on 305 heads vintage you may need to slot the four inner intake mounting bolts in the intake. That's about it.


sgp0511 01-03-2015 05:22 PM

Re: what to do, tbi or carb
well shes already past emissions age here where i live so i could run carb and open pipes no prob. is there a way to see what injectors i have on it now? the way this car looks wired i wouldnt be surprised if it was running 305 injectors already with that 350. and i know i will need to slot the inner intake holes, they are different, i think its a newer 88+ 350 and the 305 is from 80-85. ho do i go about slotting the intake and where or how do i make spacers for the the bolts once i get the intake slotted? also what sensors will I have to run with the tbi?

static80 01-03-2015 06:39 PM

Re: what to do, tbi or carb

Colour chart to identify injectors

sgp0511 01-03-2015 06:56 PM

Re: what to do, tbi or carb
ok so i looked at the wires going to the injector, and the left passenger side injector is green wire white wire, for a 5 liter and the right injector is different, blue and red? are they usually different colors? is it a different injector? on the diagram it says blue red combo is for a big block pickup?

static80 01-03-2015 08:24 PM

Re: what to do, tbi or carb
1 Attachment(s)
It's not the colour of the wires, but there are little dabs of paint on top of the actual injector.

Attachment 329476

sgp0511 01-04-2015 01:10 AM

Re: what to do, tbi or carb
do i have to take something off the injector to see this?

sgp0511 01-04-2015 06:02 PM

Re: what to do, tbi or carb
ok lifted the little piece of plastic off the injector and saw where the color mark should be, i can tell a mark was there but was dirty couldnt see any colors so i wiped it and basically i think i wiped off the color on both sides noting but silver, is there another way to find out what injectors i have? also got the intake off the 350

sgp0511 01-13-2015 03:39 PM

Re: what to do, tbi or carb
what is the sensor on the right side of the block a few inches under the manifold, basically right in the middle of the block

sgp0511 01-13-2015 04:06 PM

Re: what to do, tbi or carb
ok found out its the knock sensor, is it necessary i have this sensor? can i run without it?

gregl316 01-19-2015 12:06 PM

Re: what to do, tbi or carb
I did the swap a couple years ago and the guys here helped me out tremendously. But read the posted forms they cover it all.
Shoot I covered it all step by step and where I bought the stuff and where it was cheaper. I used Amazon and it was the cheapest but not the best. There return policy sucks. My MSD distributer went bad after the month but well with in the year but they wouldn't back it because I bought it from Amazon. So save money now or later.

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