ok im gonna be doing the swap soon but there is so many wires. What wires can I ditch and what wires can I keep? I dont want my Alternator not work or my AC not work. I also want to keep my guages working too and just get rid of the wires that the computer uses. Also what about VATS? I just need to know what wires I dont need. Also one more question about the distrutor after I take all theswe wires out how do I wire the new distubutor in?

 

so 21 people can view this and not help me? yeah I see how this bored works. I just wish I could get some help but it looks like I will be wasting money on a mechanic now. thanks guys

 

Please accept my apologies, as I spent that day traveling to your fine state and didn't have a chance to check in. Perhaps 21 people were searching for the anwser to the same question. Besides, I don't know the exact answer to your questions ("Go ahead and cut out the blue wire with the white stripe, but keep the blue one without a stripe." Sorry - I can't get into that kind of detail). I'm not a particular fan of going backwards in technology, but I try to answer questions about which I have some inkling, even if I wouldn't agree with what you're doing.

The simple answer is to keep the wires for the things you want to keep working. Most of those are obvious, such as the alternator & AC. My typical suggestion is to keep all the wires intact until after you get it running, then unwrap the harnesses, trim back what you don't need, and rewrap it all.

I know we prefer free cyber answers to all our issues, but you would do yourself a favor by buying the service manual for your car that has the wiring diagrams in it. Cheaper than a mechanic, you'll have it for future reference, and you'll learn a little about what makes your car tick.

Hope that's a little closer to how you think this board should work.

 

Well let me in on what I did.........TBI to Carb. I pulled one sensor at a time and opened up the wire looms and pulled the wire back as far as I could trace then cut the wire. I am so happy I did the swap, it did change the way the power came in but I would do it again.


Brian

 

I did it the way 57kid says to. That's just common sense. You don't want to cut out all the wires before you replace the component they went to with your swap items. As far as where to wire the distributor or anything else you buy for your car, there are usually something called 'directions' to follow. If you need help with that once you are underway, you can be more specific with the questions you post and will be more likely to get MORE THAN 0 replies out of 21 views.

:hail: IROC-Z

 

im sorry about that post I did. Its just that week was a bad week everything was going wrong with my car, I just cant wait to swap to carb this tpi is giving me some much trouble. Now my breaks are sqeeking real bad so I gotta fix those also. Would y'all recommend me getting the edelbrock kit that has the carb cam and intake? I was looking at that and thinking of doing that then buying the GM performance distrubutor. Well I appreciate y'all help that is gonna really help me in about a week or two when I order this stuff. What could y'all expect me to get for the tpi set up. THe tpi is good its just the wiring is all bad all is needs it the wiring harness other than that its all great. I wanted at least $250 or $300 for the tpi and computer. thanks

 

The prices you estimated are what a full all-the-parts-needed-to-convert-to-TPI typically goes for. Without the harness, you shouldn't expect to get that much for it.

Have you considered trying to find a harness for your current setup in a junkyard? If you found an unmolested '89 harness from the pass-through into the passenger compartment that was disconnected (not cut) from all of the places it goes, it wouldn't be that hard to put on. Wouldn't cost you nearly as much as a carb conversion, either. If you pulled it yourself, you could probably get the harness and all the attached sensors for less than a hundred bucks.

If you go through with the conversion to carb, I'd be willing to give you $200 (shipping included) for the TPI setup: base, runners, plenum, injectors, fuel rails, regulator, MAF, air inlets, distributor, computer, fuel pump, etc. Basically everything but the harness.

 

I love posts that ask for help in yanking out all of that computer crap! Just have confidence to know that your SBC has a pedigree to a time when all that it needed was a carb, distributor, and nothing else. Are you going to use a Q-Jet? Try to find the ones that begin with 70xxxx. The 170xxxx ones are calibrated too lean (because of the EGR) and non-smog primary metering rods are hard to find. It much easier to find narrow-taper primary rods for the 70xxxx carbs.

The only problem you'll have is with the A/C compressor and torque converter lockup. I had to get the schematic out to find where to bypass the ECM to restore the A/C. A kit from Summit, TCI Automotive, or vacuum switch, brake switch, and line pressure switch from a junked 1980 GM TH-200, will restore the TCC lockup. Once all accessories check out, then you can begin to remove the rat's nest of wires and EGR. In my case, I kept the fuel evap plumbing, PCV, and the smog pump is now pumping air to my back brake drums. I'm not sure how much cooler the drums are but they are a lot cleaner inside!

 

well I will see what I can do about the tpi I just dont want to do tpi cause in the long run I will get more power from carb. Maybe the $200 for the tpi Im not sure yet. I plan on using the fuel pump cause it had like 8.000 miles on it and i can still use it. The MAF sensor is shot its my 4th one in 2 years. Thats another reason im converting to carb thats another $200 or so from my pocket. I have this guy who offered me $300 for my tpi set up and computer. Everything but harness and fuel pump. So if u offer me more its yours when I get it out.

 

I have just finishing my TPI to carb swap as we speak. I have some questions before I can give you answers...

Are you going to have a computer controlled carb?

The distributer is attatched to the computer, if you yank the computer, you will need a new distributor.

Is your alternator a 2 wire or a 4 wire. I had to switch to a two wire because the 4 wire also went through the computer.

I also had to switch some factory guages to mechanical ones.
All of the factory guages are electronic and run through the computer. Modification to the guage panel was done. The three smaller center guages( voltage, fuel level, and temp. ) were replaced with after market amp, temp., and oil pressure. Mechanical guages give true readings(alot safer). Now, where the stock oil pressure was mounted in with the tach, it was taken out and the stock fuel level guage was modified to fit in where the stock oil pressure was.

Basically, the wires you keep on the wiring harness is none...
You hardwire everything all over, it's really not that much. Mechanical guages come with their own tubing and fittings and sensors. The only wires you need are the the ones coming out of the firewall infront of the drivers side. These feed the headlights and starter and main power to the fuse panel. Other than that the only hardwiring you need to do is for the distributer and the tach and ignition to the tach.

Also, you will have to get an in line fuel pressure regulator. The electric pump pushes too much your carb will flood. I'm running a mechanical race pump, but I'm using a pressure regulator anyways.

The only other thing is the coolant fan. That was a minor problem. I picked up a 185 degree fan relay kit from Painless wiring and it looks and work good.

It's alot of work removing all of the wires that we don't need but the end result is a lot neater looking.

And I don't care what anybody else says cause I just spent every weekend on this swap since September and there's no other way to properly do this without it looking like garbage or running with quirks.

Good luck.


Oh and that Edelbrock package you were mentioning rocks. I definately reckomend that on a stock motor.

Dave

 

im still deciding on if i want to do this. Im figuring for th emoney it would take to switch to carb I can convert from MAF to speed density. for the money it would take I can get this thing running good. I only want to be able to keep up with the new trans am and camaros. I dont want no race car but I want at least 350 horse. I am still not sure yet on what I want to do. I hate this i cant make up my mind cause i Look at how much of a hassle it will be to switch over to carb. I just dont have the time to really do it ya know. How hard would it be to convert from MAF to speed density? just gotta find a computer and buy a harness. oh ya my alternator has 4 wires but i think there is only like 3 of them connected or maybe 2. I bought a new conncector for it and it had 4 wires coming from it but my old connector only had like 2 or 3 so. Also if i do this im not doing computer controlled anything.

 

I did it and it took me a whole afternoon doing it by myself. It really is EASY to do. EVen with a Speed Density system you wont see 350 HP. A carb can make that easily. I know I gained A LOT of power just by switching to carb. Do it! You wont regret it...

 

I think I mistook what you meant. If your keeping the original engine and just changing the top end from tpi to carb then it should be relatively easy.

Mine took all winter so far, but I took out the 305 tpi and dropped in a carbed 1970 350, so alot had to be changed due to the difference in years of the block and such.

I just got her fired up last night and she is a beast.
I'm not using the in tank electric fuel pump. I tried to pull fuel through the electric pump using a mechanical pump, but the car keeps stalling if it's not revved up so I think the mech. pump can't pull it through at normal idle.

Anybody have suggestions. I might just put in an in-line holley electric fuel pump...?

 

I did the swap in about a week, I just used the stock in tank pump and used a afpr from mallory (the 4-port) and got a fuel pressure guage and threaded it into the afpr and set it to 6psi and mine runs fine

 

I've done this and I think I consider myself an "expert" at it now. When it came down to wiring I took all of the wires out of the protectors/holders and just went crazy. I ended up with almost no wires. After 2 hours of trying to sort through the wiring I just said "screw it" and went crazy with scissors. Cut almost every single wire. Starter/alternator/lights is all thats basically left in my engine bay ...I lucked out when I turned my car on and all the electronics still worked.

http://home.earthlink.net/~chris255/mymotor1.jpg
http://home.earthlink.net/~chris255/mymotor2.jpg

Check out those pictures. Just buy a book with a wiring diagram and go to town. If you have any doubts look it up.

If you have ANY questions ask me (chris255@earthlink.net or AIM: Chris Equals ***)

 

How does the alternator go through the computer? The only problem, which I havent got to look at yet, is my alternator on my TPI->Carb swap. I have a total of 4 wires: blk/red going to + battery, red which goes by the starter solenoid, brown that goes to the voltage gauge, and then I have (my problem, I think) a tan/white wire that turns to brown and goes into the "FP FAN" fuse. The FP FAN fuse is "hot in run" according to my wiring diagram and powers the voltage regulator

Anyway, my alternator does not charge the battery. I haven't got a chance to poke around with a test light and check things out but are you saying the tan/white wire that goes to FP FAN is grounded by the computer?

 

I just got done re-doing the wiring in my 89rs. It had 305 tpi in it before i got it. I was wanting to go carb, so i cut off the wires that i didn't need and re-did my wire loom. There were some wires that went to where the computer was that i couldn't figure out, so i just left them, but tidied them up. here's a pic of what mine looks like.