I'm thinking about swapping my 1985 Camaro from Edelbrock 1406 carb to a 1989 TPI system off a GTA. I found a guy near me with the TPI system for sale including ECM, but it does NOT come with the wiring harness. I'm trying to decide if it is worth spending the $200 for the used TPI system and then putting together a harness or buying a painless harness. This car was originally an LG4 and still has most of the original wiring intact, but a previous owner swapped out the CC quadrajet for a Holley and I put an Edelbrock on years ago. I like the Edelbrock, but the TPI is a better running system.

I found a painless harness new online, but it's about $530 for the 85-89 MAF version. I'm not sure I want to spend that much on a harness. I also found a new 90-92 MAP harness for $420. EBAY has a used 1985 underhood harness for $180, and it says it is complete underhood all the way to the ECM connection.

I have wondered if some of my old LG4 wiring can be used (like the wires running to the ECM), but I would still have to source all the connecters which would probably be expensive purchased individually.

Finding a wiring harness in a scrapyard locally is a no-go since scrapyard third gens don't exist around here anymore.

Looking for input/suggestions on this.

 

Not worth messing with. If you want efi, get an aftermarket setup. If you want to do tpi anyway. find an 89-92 harness, and set everything up like a later thirdgen. You don't want to give money for an 85-87 harness. Really though, just learn to love a carb, and maybe consider a Holley or non-computer Qjet.

 

Thanks for the advice. I'll probably pass on the TPI system.

I actually really like my Edelbrock carb, I'm just tired of the hot re-start issue.

I had done some research on aftermarket systems and will probably end up going with the MSD TBI system. Their reviews seemed better than other aftermarket TBI systems, and I like how it is basically self-tuning (with wideband O2) and I can just bolt it right on my existing Edelbrock intake. I already have a spot in mind for the fuel sump too.

 

I know this is a 9 month old thread but I just wanted to mention this. I've had Carb systems in the past, I prefer to mess with the FI. I don't have a 3rd gen yet, I'm working on getting another because I miss the one I used to have 17 years ago. If I find one that is Carb, I'm switching it to a FI system. I would prefer to keep it GM and do a TBI or TPI swap from Carb, but if I have to, I may go with either Holly or MSD's new EFI system.

 

Use a heat shield, and an electric fuel pump with return line. That will fill the bowl if any thing has boiled out of it
That is one giant hassle youre debating doing, and no power to be gained either

 

I am in the same process with my 85 TA. Purchased a complete parts car for the TPI setup and it's interior and front fenders. Nice to have everything there plus lots of pictures as it comes apart.

About the conversion, I'm a big fan. Converted a 78 Vette a couple of years ago and Love what a difference it made to the car and its drivability. Here is a link to what I posted on CorvetteForum. I did a TBI install but principles are the same as I made it a foundation to upgrade.

Regarding budget, I did it all with GM parts, cost about $400.

LINK