Hello. I need help with wiring up what I need to make the car run right after a TPI to Carb swap (crate 350 from ATK), its a 1991 Z28. At the moment I have removed the entire computer, no snipping, just disconnected everything. What I need help with is a couple things. The old alternator had 3 wires on it, one bigger one to the battery, and 2 on a plug, this plug was part of the harness for the computer, so how do I go about rewiring that? Second problem, I THINK the reverse light was one of the plugs I disconnected on the transmission, I know one of them was for the speedo, but what was the other connector? (theres only 2 I think). Also do I just hook up the starter wires exactly the way they were before? On the driver side there is a big block that probably went to the fuse box inside the car, the right side of it was plugged into the computer, the other side was connected to a wireharness to the front of the car, is it okay that I just reconnected the one that ran wires to the front of the car? In addition, I know I need to wire the fuel pump back up, where is the easiest way to access the wires I need, and once I get there, what do I need to connect to where and what do I leave alone?

Did anyone do this before and post a step by step? I am young but I can learn easily if someone just shows me what to do with a couple pictures.

Thanks in advance, Id like to get my wiring problems done before the engine gets dropped in.

 

There is a tech article and several sticky posts in the Carb forum to help you.

Sucks that you hacked up a good TPI car to put an antiquated carb on it though.

 

I have read through those stickies along with searching and reading about similar subjects, while there is good information about it, no one has really posted a "how-to" kind of thing, I guess what I am saying is I need wire colors and locations, even if someone just told me what wire is a 12 volt keyed source it would be helpful lol. Thanks for the post though.

 

You should have everything you need right in front of you, as the ECM harness that you removed coming from the passenger side fender, although occasionally shared wire loom with the other wiring, now has nothing to do with what you need to get your carburetor up and running. Your battery cables, alternator wires, starter wires, HVAC wires, gauge wires, ground wires, and distributor wires are all still there to do what needs to be done. The only difference now though is you need a vacuum advanced distributor, and a carb oriented fuel pump....

 

hey, a good carbed motor can put as much power as the TPI down and travel to higher rpms lol, no bashing

What he said about the fuel pump is true, it would be easier to just hook a mechanical one up on the block, but that may require a different camshaft? idk if the tpi had a fuel pump lobe?? basically everything you need is there. the alternator should have the big wire on the back and the plug.... hmm, i'm getting ahead of myself and just going off memory, i'll post some pictures later... i have to go sorry

 

Okay, I realize that last post was all but helpful, I'm at school and had to go to lunch or starve lol. These pictures might not be the best cause i took them in a hurry out in the parking lot.

Okay the alternator should be the easiest, the Large wire connected on the back is a direct power feed from the battery, now the plug, at least on mine, has 2 wires, one white and one red, red is also power, the white is some sort of return or something, to tell you the truth i really don't know, a friends dad that rebuilds alternators and starters said i didn't need it... the red wire connects with the thick red wire on the back and they connect to a think black wire from the batter. As shown.

Ignore the orange duct tape, its connected with a heavy duty slide terminal, i've always had it this way but i don't think its perfectly right, i'm just telling you how i have it.

As for the starter, i couldn't get any pictures cause of the time limit and i didn't want to climb under the car in my good cloths lol

BUT from the way i remember it, there should be a large power wire running directly from the battery to a large terminal on the starter solinoid, off the solinoid should be 2 more wires connected to a smaller terminal (i think there are 2 wires on one terminal, but there might b 2 wires for the 2 terminals, hopefully someone can fill in the blank space...?) Where these wires go i'm not 100% positive, i'm sure one runs to the electrical connection on the distributor cap. I wish i could be of more help...

 

Thank you for all the responses, I should have stated earlier but I already have a regulator setup for the fuel. I spent all day (College vacation put to good use) and went through the entire wireharness, cut all the tape and traced every single wire to either a sensor or to one of the huge 'plugs' that goes on the driver side relay area. Basically what I did, because I dont plan on ever converting back to TPI, was taped off and cut all the old tpi sensors and fuel injector wires, minus the one sensor that goes to the front of the intake to turn the fans on, and taped all the wires left on the harness back together. What I am hoping is that by doing this I can just avoid all the rewiring and hide the new tiny tiny harness in the engine bay. My alternator wire is actually a different color, its brownish not white. I traced that wire back to the driver side fuse panel area, so I left that intact cuz I have no idea what thats for. The other wire, the thick red one, I believe came from the starter, as I dont see any place for it on the battery, I think my starter had a few things stacked on each other, I remember it being a mess when I took it off. Anyone know if what I did with the harness is OK?

 

actually if you wanna hide that little wiring harness just pop your dash pad off and hide all the wires behind your dash. run all your wires out through a single hole and youll never see that harness. its what i did and it looks 99% cleaner.

 

I didnt even think of that, I have to take that off anyways to wire the new tach, thanks for the tip!

 

That's really selling a carb short.. TPI doesn't make horsepower.. it makes torque.. if you wanna go fast cheaply carb is the only way to go.. if you have the $$ there are a ton of good FI setups that make serious power and get good fuel economy. But that's beating a dead horse..

 

I put a carbed 383 in my 88 TPI iroc and I love it

 

Well I got the engine in on Sunday and its looking great. I have a Weiand Stealth intake and I was told "theres no way thats going to fit under the hood", well, it does, with room to spare (yes with an air cleaner). That coupled with all the wires minimized greatly it is looking good, Im waiting on a starter but it should be running by the end of the week. Thanks for the help from those of you that replied. Ill update again if I have problems later. Thanks again.

 

like the idea of how to hide wires....dumb question time what "hole" are you referring to?