Question about tbi to Rochester 2 barrel

[byopp12789]

So I just bought a 1987 Chevrolet r10 with a tbi on it and the tbi is shot so what I was wondering was I have a Rochester 2 barrel laying around would it fit in place of the tbi and would it run right with all those sensors and everything not being hooked up to the carb.
Thanks, Bryson

[MARKDTN]

You have no mechanical fuel pump so you will have to deal with that (you can't use the electric in-tank pump with a carb). The block may or may not be machined for it. The electronic distributor won't work without the computer. But in simplistic terms an intake is an intake. If you can bolt on a carb leak-free and supply fuel and spark then yes it will run. If it were me, I would much rather make a TBI work than a 2-bbl carb. The TBI is a very simple system. You will also have issues if you have a 700R4 transmission with the TV cable and a 2-bbl.

[byopp12789]

Originally Posted by MARKDTN

You have no mechanical fuel pump so you will have to deal with that (you can't use the electric in-tank pump with a carb). The block may or may not be machined for it. The electronic distributor won't work without the computer. But in simplistic terms an intake is an intake. If you can bolt on a carb leak-free and supply fuel and spark then yes it will run. If it were me, I would much rather make a TBI work than a 2-bbl carb. The TBI is a very simple system. You will also have issues if you have a 700R4 transmission with the TV cable and a 2-bbl.

Maybe you could tell me what could be causing it to flood at idle? I know nothing about these things the guy told me it needed injectors but after changing them no luck and I know a little about how to work on a carb that’s why I was ready to give up to one but if I can get this fixed I would rather go tbi route. Thanks, Bryson

P.S. I pulled the plugs and all 8 are black. Could it be some sensor or something? If you can help let me know. Thanks again
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[jayoldschool]

Define "shot" please. The TBI is easy to work on, cheap to service, and ultra reliable. I wouldn't downgrade to a carb.

[byopp12789]

Originally Posted by jayoldschool

Define "shot" please. The TBI is easy to work on, cheap to service, and ultra reliable. I wouldn't downgrade to a carb.

At idle it will not run to save its life and i was told by the guy I bought it from it needed injectors but after changing them that didn’t fix it so I would just rather give up to a carb because I know a little about them and I know nothing about the 87 tbi. Maybe you could help me? Give me more insight on what could be causing it to flood at idle? Thanks, Bryson

P.S. I pulled the plugs and all 8 are black. Could it be some sensor or something? If you can help let me know. Thanks again
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[clay68c10]

Will it start and idle with the engine cold? Does it get worse as it warms up?
The injectors rarely go bad on these, as you found out.
Do you have a fuel pressure gauge?

[rpmerf]

Clean up the plugs. Run the codes. Disconnect the battery to reset the ECU. If it gets better after the ECU reset, then gets worse again, it'd blame a sensor. If it stays about the same, I'd look at non-sensor issues like fuel pressure. A good manual should have troubleshooting steps.

Found this with a little searching.
http://www.73-87chevytrucks.com/tech...TBISystems.pdf

[roboticjunky]

If you can found a good scanner that tells you what your sensors are reading, that will really help.

I had a truck that had TBI and ran rich and would die when you put in gear. MAP sensor wasn't reading right. Ended being the wire going from the MAP sensor to the ECM was bad. So that bad wire made the ECM think it at full throttle and ran really rich. Bad o2 sensor could also make it run rich. Bad coolant sensor would also make the motor run rich, because the ECM will think it's really cold when it's not.

You can check the MAP sensor by using a multimeter and checking to see if it's getting 5 volts from the ECM. Then you can check how much voltage is going back to the ECM should be around 4.90 volts or so. You can also check your coolant sensor, which is next to the thermostat housing, by unplugging the coolant sensor and setting your multimeter to ohms. Then check the resistance across the 2 prongs on the coolant sensor. Reading should be around 5670 if the motor temperature is 50 degrees F.

Also do a visible check like is everything plugged into the sensors and are there any broken or burnt wires.