Hello everyone.
I need a little help. Currently installing V8 TPI into my '91 RS Camaro with a V6 MPI. The TPI harness and computer are from a '85 Camaro. What should I expect to encounter with this conversion? I do know that the '85 is unique into itself based on the info I received on chevythunder.com. I also realize that the '91 uses a speed sensor in the tranny v.s. the '85 using a speedo cable. So what will be required in order for the speed sensor to get power? Has anyone tried this yet? Thanks in advance.

 

If I were you, I'd pitch the 85 harness & computer and go at least with an 86-89 MAF setup, but preferrably a 90-2 speed density system.

For about $150 you can either have your harness modified & get a computer, or find a full harness & computer.

The reason I suggest this is because the 85 computer sucks HARD. It's ok with a stock 305, but that's about it. It's too stupid to work well with major mods, and because it's so rare, getting good PROM tuning help is hard. You're also going to find yourself in a sh*tty situation if the MAF burnoff relay tanks. They're hard to find and insanely expensive.

You're also going to have VSS issues. I believe the VSS in the 90+ cars is a 4khz pulsed unit, and the 85-89 computers need a 2khz pulsed signal. I might be backwards on that, I don't remember. You can buy a converter, but it's expensive.

 

hi i happen to have a harness its painless 85-89 tpi harness complete only needs one connector its the maf connector i needed it for my 87 trans am i had to extend my maf wiring harness so i had to use it, to be able to use it for my ram air hood and intake setup.the harness has never been used i bought it a while back for my 87 monte ss but decided it be too much work to do. I also i have a holley external fuel pump. i bought this stuff from jegs. i paid 300 for harness and 150 for fuel pump. if ur interested email me at PerfectionGoku@aol.com. make me a offer. i no longer have my trans am or the monte ss. i now have a 96z28.so i wont need the harness. i sold my trans am to kid from NJ i am sure he probably showed pics of his car has a Ram Air 2 hood the GTA is flame red.i liked the car but decided to get a 4th gen. my brother owns a 90 Irocz. car is pretty fast runs 14.3 @ 95 stock. thanks.

 

I certainly don't want to discourage you from using a Painless harness, but I would check with others that have installed it in a thirdgen before. If I remember correctly, it is too short to follow the stock routing path. If you don't mind passing it directly through the firewall that's not an issue, but if you want to maintain the stock routing, you may need to do some major hack & slash work to it.

I don't speak this from experience, but it is something that I've been made aware of, so I'm just passing it on to you. I do know that Painless has a long & short harness, but I believe that both are too short.