So, I've got a wrecked 89 Trans am with a TPI 305, I bought an 85 Trans am with a carbed 305, I want to put the TPI engine into the 85.... how much of the wiring am I going to need to swap into the 85? I'm not very familiar with working on fuel infected engines, but I figure this will be one great way to learn ....any other things i might need to know before i get too deep into this would be great :-)

I've also got a built carbed 350 that I could use in this... but I have no idea about emission laws and if or how I could make it pass, so I was thinking I'd save that for my dream 69 camaro that doesn't have to pass emissions, or this trans am in a few years when it doesn't have to pass....but if anyone knows how I could make it pass let me know (I don't want to spend the money putting the TPI on the 350)

Thanks for any help

 

You are going to need all of the under-hood harnessing that goes to the computer, and it would probably be easiest to change the rest since you're changing induction type and accessory locations. Be aware that little things like alternator and AC connectors changed between those years, so it's not just a matter of changing their routing.

I'm not completely sure of the rest, but you are going to need wiring/switches/relays that run the in-tank electric pump, for instance.

Personally, if I was faced with this choice, I'd do the complete TPI changeover into the '85. And I'd keep the serpentine accessory drive (hint - you can remove the entire AC system w/o opening it up and switch it from one car to the other). It may be a little more work than just converting over to carb, but worth it in my opinion. Technically, it's the only emissions-legal option as well (although a 350 TPI could be emissions legal as well if done correctly - shouldn't be too expensive unless the 350 is really hypered out).

 

I am Doing the same swap with my car but going from a carbed 305 to a tpi 350 and its ALOT of work. You have to drop the rear end to take the tank out so you can switch to an intank fuel pump, (if your going to try and do it factory) run all new fuel lines, new computer, wiring under the hood (as mentioned before) wiring to the fuel pump, also wiring for the anti theft, which you probably wont use. If i were you i would just get a wiring harness from painless wiring for an 86-89 MAF if you wanna stick with MAF, or 90-92 speed density. Ive heard 85 tpi isnt really a good system do to there MAF system.

 

what's the deal with the "painless" wiring? what's so special about it?.... i already have ALL the wiring and ALL the parts i could need out of the 89 TPI car.... i can even still start it up... the frame is just so bent it's not worth fixing.... you said the 85 isn't good cuz of the MAF..... well ... it's the TPI out of an 89... the 85 is the currently carbed one that i'm putting the TPI into..... .... and when u said new fuel lines and what not.... the ones out of the 89 would work just as well... no? .... and what's wrong with the ones that are already in the 85...? they take a different route?

Thanks soo much :-)

 

Sorry i didnt see 89 from the wrecked trans am. The fuel lines from a carbed 85 are small and support pressure for 14psi while tpi supports 47psi and yes they do route differently. The 89 tpi routes from the tank along the drivers side and up on the drivers side of the engine where as the carb. comes along the drivers side from the tank and up on the pass. side of the engine. The painless wiring i recommended because its easy to install everything is labeled and theres an instruction booklet that comes with it and tells you everything you need to install and why.

 

Painless seems like an unnecessary expense to me. Since you're starting with a complete donor car, label everything as you take it out (you don't need to know exactly what it is, just were it was and what it connected to).

Having the two cars side-by-side is nice because you can see what is different and know what you have to change.

 

Thats true, although i dont like used wiring myself, but hey whatever makes it easier right?

 

well, easier is a close second to less expensive :-P... If it was Insainly easier for some reason i might go with the painless... .... I guess the wiring just doesn't feel used to me, cuz the 89 was my car... didn't just buy it junked.. and i know everything funcionted and still functions properly...now the wiring in the 85 is another story.... they apparently had a fire in the engine.... i'm amazed the thing still ran.... looked like about half of the wires were melted downt to the actual wire.... so, do u think it would be easier to just rewire the under hood area.... or do EVERYTHING down to door locks and hatch release?

I have a feeling I should buy a crate of fuses... :-)

 

I'm in the process of doing this and am getting much closer to completion.

My advice is to take the '85 and pull the motor, all wiring, etc out of it...yank out the dash and the underdash wiring. Then bit by bit, transfer each item over into the new car putting it in the same way - including fuel lines, etc... If you have a digital camera, take pics as you disassemble things - then you'll have instructions on how it goes back in when installing it.

All you are really doing is swapping the drivetrain onto an older frame. I'd think it should be pretty straight forward. Expect to have both cars out of commision for awhile though.

HTH...

 

that's about exactly my plan.... I have all of the interior out of both of them now cuz i'm swapping that too.... and I have the engine out of the 85.... i even have a reason for swapping the rear ends besides the fuel tank.... the 89 has posi :-P .... I've just never done something this extensive before.... so i thought any advice couldn't hurt.... and i've already started taking pictures :-P


thanks :-)

 

Sounds like a fun project. Also remember that you'll need to run the power wire that goes back to the fuel tank, since I'm sure your '85 didnt have that provision.

Good luck and have fun!

 

Hey guys!

I'm doing this swap right now as well.


I'm swapping a 355 tpi from an 88 iroc to my 85 camaro that has a carb'd 305. The rear is going into the 85 because the 88 had the posi and disk brakes, swapping the whole dash, wiring, dash guages with it, the whole wiring under hood and body harness and all of the fuel tank parts and such



Cant wait to see the tpi in that engine bay =)

 

In my case, I just snagged the intake/wiring/computer from a guy who was parting out a car locally. Since my car was originally an LG4, I have less to do...but more "customization" of the wiring since there are extra lines needed to power the fuel injectors and such. I've got the intake on and I must say I'm already happy with the improvement in looks over the carb/aircleaner...lol.