'64 TBI swap issues - Impala Tech
Electrical & Wiring Troubleshooting electrical problems

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post #1 of 4 (permalink) Old 04-03-2020, 12:10 PM Thread Starter
Join Date: Apr 2020
Posts: 2
'64 TBI swap issues

Hey all, new to the group here!

Picked up a '64 impala that was in the midst of being restored. Its a 4.6 with a TBI conversion. Engine wouldn't start due to no fuel. Pump was dead, lines were clogged. Ended up replacing the in-tank pump, fuel lines, filter, and rebuilding the TBI. I can manual pulse the injectors and they have a good/strong spray pattern but when the engine cranks, the injectors do not fire. The wiring is pretty messy from the previous owner. I've checked power at the injectors connector and there is 12v at on pos and then drops to 8v during cranking- but no pulsing/fluctuating voltage. Wasn't sure if I was metering correctly so I got a noid light set, and no lights during cranking.

I am wondering if someone has a write up from a swap they've done and/or seen? Trying to backtrack and find the source. Or at least get a direction to start.

Thanks for the help!
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post #2 of 4 (permalink) Old 04-03-2020, 01:12 PM
Join Date: Jan 2006
Posts: 12,926
Welcome to the Team!

Sorry I am no help as I have no use for an electronic carburetor, which is all TBI is. All of the draw backs of EFI with none of the benefits which is why the factory went to TBI then port injection and now direct fuel injection (each iteration raising the cost. Unfortunately there isn't a factory carbureted V6 so you have to go to a aftermarket manifold and a 560 to 600 cfm carb.

Big Dave

Big Dave
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post #3 of 4 (permalink) Old 04-03-2020, 06:08 PM Thread Starter
Join Date: Apr 2020
Posts: 2
Thanks, Big Dave!

Yeah, there is a computer and harness that was installed with the TBI. Seems to be semi common to get a form of EFI on the V8. Still trying to hunt down why the injectors are not firing before going to mechanical. The engine will start if I pour fuel into the carb.
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post #4 of 4 (permalink) Old 04-03-2020, 06:15 PM
Join Date: Jul 2009
Location: Canada
Posts: 1,486
What's the TBI off of? Once you know that, it will be as simple as following the trouble shooting tree from the FSM. It will go like this:
- is there 12v on the blue wire with key ON to RUN? If yes, if no... etc etc. Follow the tree, you will find the problem.

Two doors, four doors, wagons, and ragtops.
jayoldschool is offline  
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