Kevs87Z28

hey guys i am trying to confirm if the information i have collected through various threads is correct. if i have left something out please notify me as i will be swaping soon.

Fuel Lines - rubber, braided, or metal are all fine.

Clamps or Fittings - either can be used

Fuel Delivery - you can either remove electric pump in the tank and use a mechanical or keep the electric pump and get a 3 port return style regulator such as Mallory Part # MAA-4309 or use an in-line electric pump (this will require removing the stock pump too)

Fuel Filter - a fuel filter needs to be placed inline between the regulator and the carb.

Hooking up the Regulator:
There are 3 lines on the driver side fram by the master cylinder.

the large line is the delivery line and needs to be put into the appropriate port on the regulator.

the other line is the return line and it too needs to be connected to the proper port on the regulator.

the last line is the vent line leave it connected to the canister.

the third port on the regulator is the pressure port and it is what you run fuel line to the carb from.

Throttle Cable - you need a throttle stud similar to Holley part # 20-37

Transmission Kickdown Cable - you need a stud smilar to Holley part # 20-40

Cable Bracket - you need to get a bracket similar to Holley part # 20-95 or Summit part # SUM-G1414

If you are going with a manual choke carb and want electric choke get a kit similar to Holley part # 45-224.

Wiring and Other issues to deal with:

The fuel pump in the tank will not turn on without the ECM so you need to splice into the green/white wire at the relay and connect it to the ignition wire at the fuse panel.

You need a non computer controlled carb with vacuum advance. i am using a stock HEI distributor with the coil in the cap. you will need to splice into the old plug for the stock coil to get power. the thick pink wire gets plugged into the BAT (+) terminal and the thin white wire gets plugged into the TACH (-) terminal. either use a stock plug if you can get one or just use female electrical spade connectors.

The Harness on the driver side by the brake booster has everything you need to run a non computer controlled carb. it contains all the connectors for the starter, alternator, coil, and sending units for the oil and coolant temp.

you will need to run a wire from the ignition wire in the fuse panel to the electric choke if you go that route.

most carbs have a timed-vacuum port to run the vacuum advance part of the distributor (its a silver ufo or ball like thing on the distributor.)

power brakes can be run off the pvc port on the carb if it doesnt have a port for the power brakes and just use a breather for the pvc.

you must wire a switch to lock up a 700r4 conveter if you want to. if not you will loose around 5 mpg on the highway. the switch can be wired through the diagnostics port under the gauges.

things to know:

carbs only need 5-8 psi fuel pressure so you need the regulator if your using a stock electric pump or a mechanical pump and a carb pick up for the tank is needed or you can remover the in-tank pump and use an in-line pump.

i saw in a thread the the fan and a/c have issues with not having an ECM but im yet to figure this out yet. i will post later if i find anything out.

the gauges and everything will run without the harness from the passenger side fender. you can just unplug and remove that.

five7kid

iTrader: (14)

It's a decent list, but some of the particulars will vary with the vehicle you're starting from.

As for the fuel lines, the ones being used by the EFI are the same ones you'd use for supply & return w/carb. As for the vent, leave it hooked up to the charcoal canister (you'll need to figure out the vacuum purges for the canister, I'm not going to attempt to detail it for you).

There's one other choice for fuel pump - in-line electric. Removal of in-tank electric recommended if you go that route as well.

The regulator ports should be marked supply or inlet, outlet, and return. More commonly people would call the 3rd port the return, but doesn't really matter which one is called 1, 2 or 3, as long as you get the function correct.

Your Holley p/n's need some dashes...

StealthElephant

Get a thermostatic fan controller to operate your fans.

Holley sells a bracket for you throttle/TV cables.

http://www.holley.com/HiOctn/ProdLin...CA/f20-95.html

The little things are going to be the major time eaters.

My buddy completely rewired my car for me. The old TPI harness came out, and he took the existing starter harness that went into the cannon plug in the firewall and completely rewired the car for me. It's 10x cleaner and is so much simpler than before.

I wish I had kept a diary of all the little things you're going to run into while doing the swap. I swapped my TPI out of my 87. Good luck.

Kevs87Z28

yea i already have the holley part listed.

Cable Bracket - you need to get a bracket similar to Holley part # 20-95 or Summit part # SUM-G1414

thanks for the help.

whats a thermostatic fan controller? where can i get one? whats the price?

Kevs87Z28

ok yea im starting with a 87 z28 305 tpi. so some of your wires may be different colors depending on the year.

ok i was told the outlet port goes to the carb. someone else called it a pressure port but its the same thing. always check the instructions on parts like this anyway. you dont want to mix the lines or it wont run and you will be pulling your hair out.

so inlet is the delivery line from the in-tank pump, outlet or pressure port goes to the carb, and return is just that. in case someone didnt follow that.

i edited the top post to reflect most of the changes. i am making this thread to aid others who may be like myself and wish all the info was in one thread. thanks for helping.

Kevs87Z28

top has been edited further. i checked part numbers at advance atuo and autozone and the cames are the same for 4 barrel 5.0 models and tpi models. so no need to get new cables.

also if anyone who has done the swap knows anything i am not mentioning please chime in. i plan on doing the swap in a few weeks so i will document and post what i run into after that also.

IROC_385Z

Isn't there a second adapter that you need?

http://cgi.ebay.com/ebaymotors/ws/eB...spagename=WDVW

Is this bogus? I know I sure burned up my tranny when I switched to carb...even using that other holly bracket. Now I know why the tranny never shifted right

five7kid

iTrader: (14)

You need the correct geometry for the TV cable, and the standard Holley throttle arm doesn't have it. That bracket would make getting that much simplier.

IROC_385Z

What other method is there to achieve the correct geometry?

five7kid

iTrader: (14)

Fabricate.

Kevs87Z28

i was under the impression that the adjustable bracket from summit would do it. there has to be someone selling parts for this swap.

anyone have pics of the fabricated bracket or something that works?

Kevs87Z28

i heard either get part # 20-112 and #20-119 or just get SUM-G1414 and SUM-700202 for holley or SUM-700203 for edelbrock.

i looked through, many posts and most seem to do this or they started with TBI cars and somehow used the stock bracket or fabricated.

i am going with SUM-G1414 and SUM-700202. we will see how it goes.

x5finger

I also heard things about the cable geometry and whatnot. However, when I was installing my parts I took some
measurements: from the bracket to the end of the cable on both the TPI and the carb (with the holley bracket), full
throttle and idle. They measured the same, so I figured it was ok.

Kevs87Z28

i have heard so many different things about this swap. mainly surrounding the trans. like the lock up and the cable. i wish someone had documented step by step for a 305 tpi auto camaro to carb. but i cant find it so i guess thats why im doing the reasearch myself. maybe someday someone will find this post and go omg this is just what i need. haha

bluegrassz

iTrader: (3)

After I did my swap, My speedo doesnt work anymore. I have the 92 gauges and I got rid of the computer. Just something to think about.

Kevs87Z28

the reason your speedo doesnt work is its driven by the ecm. you should research beforehand. seems like you stepped into it too early.

bluegrassz

iTrader: (3)

Yeah, I know it is driven by the ecm. I wasnt too suprised when it didnt work. I also new that I had the option to order a box that would make it work. I just dont want to shell out the money for it since it isnt a daily driver and mostly sees track time.

Just thought I would post this up for anyone considering doing the swap.

bluegrassz

iTrader: (3)

I ordered the holley throttle cable/tv cable bracket. then I got a stock throttle cable off a TBI car and used the stock tv cable. I did have to cut some of the plastic cover on the end of the throttle cable. The flared part that slides would hit at WOT. I just trimmed it and it works fine now.

For the record I went from TPI to carb and have been happy ever since.

Kevs87Z28

was your tpi cable longer? i bought a new throttle cable a couple monthes agot and it BARELY make it to the bracket on the tpi unit. maybe tis will help with the carb swap here in the next 2 or 3 weeks. i think maybe they gave me a tbi cable but im pretty sure i checked the part #s and they were the same. either way the motor should be finished here soon so i will make notes and post more.

bluegrassz

iTrader: (3)

the TPI throttle cable was longer than the TBI cable yes. I used the stock TPI TV cable and it worked out fine. Just make sure you get the holley non-adjustable kickdown bracket. The one thats for the throttle and tv cable. You will have to loop the TV cable just a little to get it to fit.

Kevs87Z28

hey guys i did the swap. everything worked out fine. only things i ran into were...

the TPI TV cable is too long so i got one for a 84 305 and it works ok. it is still too long but i was able to loop that one enough to fit the bracket.

i had to cut the notch on the tv cable off so i could turn it to be able to push the adjustment thing.

the computer harness contains the wiring to the fuel pump relay and fan relays.

so i will manually wire the fans to a switch and a direct line to the battery.

the fuel pump i couldnt figure out what to do so i hooked up a fuel pump i got from the parts store for a 79 4 barrel 350 Camaro.

i attached a length of 3/8 rubber fuel line down along the radiator support over to the driver side and onto the 5/16 return line. that line goes to the bottom of the tank and you dont have to modify the sending unit or take the electric pump out.

the other spot on the fuel pump i bent some metal line 90 degrees and attached a tube nut and tube sleeve to a 6AN fitting on braided line up to the carb.

i havent started it yet since i didnt have the y-pipe welded yet (modified for hotchkis subframe connectors) and i forgot power steering fluid for the new serpentine system and it was 11 at night and nowhere open. i will go back up thursday or friday and fire it up hopefully. oh and a little tip change the motor mounts. if i didnt do it now i wouldnt have been able to do it without taking off the A-arm.

five7kid

iTrader: (14)

I don't believe that is correct. The VSS signal from the tranny goes to a "module", which feeds both the ECM and speedometer. As long as the train to the module and speedometer aren't interupted, removing the ECM shouldn't affect the speedometer. Something must have been done to disable the VSS and/or module.

weigesco

Just for information. I used that Cable adapter that was listed from Oregon Performance Transmission and it worked great on my TBI to Carb swap.

Kevs87Z28

doesnt ecm stand for electronic control/command module? either way without the ecm the vss doesnt function causing no converter lockup and i believe an innacurate/nonfunctionaing gauge. they do make an adapter for this problem its made by jegs, summit, tci, painlesswiring or b&m if i remember right. i cant remember exactly which. any member that has done the swap with electronic speedos should reply if for nothing else but to notify potential swappers of issues to deal with.

bluegrassz

iTrader: (3)

The only things I removed were the computer and any wiring going to the TPI system that wasnt needed. Eveything else is intact. All my gauges work except for the speedo. Its a 92 SD wiring harness for the record.

Kevs87Z28

ok swap is done. i ended up modifying a stock cable bracket. it was tall thats the best way i can describe it. i went to the junkyard ant there was 2 different types so i got both and the tall one was the easiest to modify to fit.

i had to get new throttle and tv cables. both were out of a 84 camaro with H code motor.

fans i had to run directly off the battery with a switch.

converter i havent got to lockup because i need the painless or b&m kit since this engine is non computer controlled.

i also got a mechanical fuel pump for a second gen camaro with a 350. i hooked that up to the return line so it can suck the fuel from the tank and not through the old electric pump.

i also lost the seal that goes in the transmission around the tv cable so i had to get another one. it was part 25518260 and came from a dealer for around 9 bucks.