First off I am sorry to start a new thread but I did not want to take a current thread off track and I have been looking for more information for converting from my tpi setup to a carb since I need to replace the motor in my 87 TA. I have read many articles and recently everytime I search I am told my keywords are too common. Many threads talk about the major parts involved in the swap but I am wondering about the smaller pieces such as the vacuum canisters under the hood, extra parts only necessary for tpi, etc. I would greatly appreciate any help or if someone could simply direct me to a thread where these "minor" details are.

Thank you

 

My experience:

I got a 406 crate motor, the serpentine system wasn't compatible. The heads that came with crate motor didn't have the proper accessory bolt-hole pattern to my 92. I bought some AFR Heads that did the trick. I kept my A/C. I remember having to re-configure my alternator position to make that fit. I don't have an airpump assembly on mine anymore.

The camshaft specifications would not provide enough vacuum to power my brake system. I had to get a vacuum pump which solved the problem.

My MSD 6AL box that I used with the Fuel Injection works fine with the HEI set up I got, MSD Pro Billet Distributor.

Keeping my vacuum lines routed properly was no problem.

The biggest thing I was concerned about was the throttle/detent cable set up. Because i wasn't aware of how to do that, i took it to a reputable shop in town and they fixed it up nice.

I snipped all the wires that aren't needed anymore.

Thats all I can think of right now, I learned alot enroute. Still learning. hope this helps a little bit.

 

Okay thanks, what did you do with your fuel system? Did you use a regulator or a mechanical pump. Also what did you do with the vapor canister from the tank that usually routes back to the tpi to burn?

 

You use the stock pump and fit a bypass reg in the engine to cut the pressure down

https://www.thirdgen.org/carbswap
http://5finger.8m.com/tpi2carb/tpi2carb.html

CCP is operated by the ECM which will no longer be working so you need to duplicate what a early carb engine had

 

where would be the best place to find out how to duplicate the vapor system, or how did you do it if you had to on your engine?

 

When I swapped in a carb'd 350 to replace my V6, I picked up an old vacuum charcoal can from an older Chevy truck at a local junkyard. Tank vent line connected to one port, and the engine side I T'd into the PCV line to the carb. I also made a bracket to mount it behind the front bumper so it is out of sight.

I kept the original fuel pump and used a Mallory 4309 regulator connected to the original feed & return lines.

You'll also need a new throttle cable as the TPI cable is too long. I grabbed one from a carb'd thirdgen at the same junkyard.

I'm not sure if your stock ECM can control the radiator fan. On mine, I got a fan switch from summit racing that threads into a cylinder head. Connect the ground wire from the fan relay to the switch to turn the fan on & off.

Same thing with controlling the fuel pump relay. I just ran a wire into the cabin to a spare connection on the fuse block that only has power when the key is on to send power to the fuel pump.

I had already removed all the AC stuff(no need for it in PA when you have ttops) along with the cruise control(don't use it). Initially I used a v-belt setup from an early thirdgen, but then I came across a serpentine setup from an early 80's full-size GMC van that I used. Just running alt, water pump, and power steering pump.

 

If you use the original TPI fuel pump oil pressure switch you don't even need that.
Engine will start with the fuel in the carb bowls , as soon as the engine cranks over ,the switch will run the pump and the pump will turn off as soon as the engine dies when the key turned off

 

I wasn't sure of that, that's why I wired mine to a separate power source. Good to have confirmation though.

 

Sorry for the delayed response but I took it to local shop, told him the engine I bought & he installed a whole new system. An inline external fuel pump, larger lines, fuel pressure regulator & gauge, return line and filter. He did something (beyond my knowledge) with the old fuel pump, bypassing it all together.

 

The best way to bypass it is to drop the tank and replace the pump with a piece of rubber fuel line or steel line. Then use an inline filter before the pump.

 

If the ECM is disconnected, will this switch still engage the pump or willl I need to leave all the wiring and computer intact to utilize the switch?

 

Only the pump relay is controlled by the ECM

The OP switch is a completely independent , mechanical switch wired in parallel with the relay as a backup so you can
start your (TPI) car with extended cranking should the relay fail.
For a carb setup it becomes your primary pump switch and you can delete the pump relay



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