As the title says i am wanting to swap to tpi but im wanting to make sure im not gonna spend over $600 just on swaping to tpi. So i have been searching around and the best info i found was this https://www.thirdgen.org/tbitotpi
i just wanted to double check on people who have done this swap if it was the same thing they did or is there other things i would have to worry about. Also if you guys did it a other way please post it up on here since i think it would help other people who want to do it too.
Thanks

Rudy

 

I did it about a bazillion years ago, 1995 i think, back then i paid about $600 in parts alone, but I also swapped to a 350 so had the added expense of a rebuilt motor and exhaust upgrades on top of that.
are you planning to swap the whole motor or just the intake?

 

honestly its a straight forward swap... i did it about 8 years ago.. but theres always little things that will be unexpected and jack up the cost...

 

Its been a while since I did mine.

I used a mass airflow setup off an 85 vette. Got a 90-92 ecm and a painless harness. Had to buy a set of injectors and a knock sensor.

 

Since you have a '91 RS, you can re-pin your existing wiring harness and use that for a speed density setup. I did it, took me maybe an hour and a half to do at most and I've never done anything like it before. That'll save you some money, don't need to get a full harness. You just need the computer, connectors that plug into the computer, and the injector wiring clips. I bought a setup for $400 that had everything including a full wiring harness but after I had the new-to-me harness laid out in the engine bay I realized it was for a firebird so some connectors were on the wrong side of the engine bay (battery, alternator, evap canister are all switched around) plus my original harness was in much better condition, so I cut off the injector plugs, took off the computer connectors and followed the instructions, double checking what each wire did with my service manual. The instructions on here are spot on.

The rest of it is pretty straight forward, you're just replacing the intake and changing the fuel pump and knock sensor.

 

I am also gonna swap in a 350 i have rebuild, and since i love the look of tpi thats the reason i decided to try to go to tpi. But as for you guys that done is there other parts im gonna have to buy other then what is mention on that article. Also as for me modding my own harness i have no experience at all with wiring thats the reason i dont want to try that even though i already have 87 tpi harness from the engine i have.

 

you will also need (aside from the obvious)
tpi fuel pump
tpi throttle cable
tpi tv cable
you need to decide if you want a maf system or sd, both have advantages you can search the site for more info.
Your 87 harness was designed for a maf system, if your going to use it you will need a maf ecm, (can't think of the number right now) and a maf sensor. also some of the plugs will be on the wrong sides, and the bulkhead connector and the insrtrument panel connector will need to be repinned, they will not match the corresponding connectors on your 91
you may be better off converting your existing tbi harness to sd tpi and eliminate the maf sensor all together. your existing map sensor should work fine.

I'm sure there is more but this is pretty much what I remember about it.

 

Using a SD TPI, he has to bypass his VSS buffer box and move one wire on his C207. Everything else is plug and play

 

Pocket does the bypass have to be done by tuning it or how?

 

Street & Performance sells a plug in adapter harness that makes the job super easy and a very clean install.

http://www.hotrodlane.cc/

 

http://www.austinthirdgen.org/mkport...SS_V8_vinE.jpg

This is the buffer diagram. To bypass you cut pins C and F loose and splice them together. Then move the speedo pin from the engine side C207 (clear) from pin D (GRY) to pin K. That gives the signal a strait shot from the ECM to the speedo

Thats all, 5 mins of work

 

if you look arround you can find good deals. i found complete motor with everything on it plus the engine harness and ecm its a 305 but it's tpi and i just gave 250 for it all.

 

This is the buffer diagram. To bypass you cut pins C and F loose and splice them together. Then move the speedo pin from the engine side C207 (clear) from pin D (GRY) to pin K. That gives the signal a strait shot from the ECM to the speedo

Thats all, 5 mins of work

I dont understand what is ment by this part: Then move the speedo pin from the engine side C207 (clear) from pin D (GRY) to pin K.