choekstra17

I am coverting my 1992 camaro 305 tpi to a 355 carberatued engine. I was told before that i can just remove my computer and wiring harness connected to the computer and that would be it. I beg to differ and need help. I pulled out my wiring harness for the computer and the starter wires were connected to it and it also ran iton the main wiring hareness too. Where do i start in figuring out this situation?????????? I also plan on keeping my in tank fuel pump and running a regulator. does the computer control that function?? PLEASE HELP

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84'B.A.T.A.

you can absolutely get rid of that junk computer every bit of it, and the wiring for it. just rerun your starter wires from the battery, and wire your fuel pump to your wiper fuse so that when you turn the key your fuel pump will turn on and off.

five7kid

"Junk computer"?

Not understanding something doesn't make it "junk".

Stekman

...And wire up the alternator, and distributor....rumor has it those are pretty important, too.

Your regulator is a return-style, right?

84'B.A.T.A.

ya i kinda figured if hes doing a swap he wouldve known those basic things, and obd1 is crap

choekstra17

listen, no need to be a ****, i am just asking questions here, i would appreciate answers not ******* remarks. so unlees you can help me stay out of the conversation. THANKS and as far as the help above it really just confused me because just wiring the starter to the battery doesnt give me the resolution for the ignition wire back to the key to start it. Someone who has done this b4 please help

91Camaroz-28

Hi, i just built a 355 carb engine for my 91 z-28 in place of the 350 TPI, here is what i did and everything works perfect. I simply just left my wire harness there along with the computer and then droped the motor in. all the wiring hid real nice behind the engine. then i wired up the HEI distributer and a external holly fuel pump, ran all the pluming and she fired right UP! i havn't had a single problem yet. all my gauges and light work, the starter and alternator still work. everything works. If you have any more questions just let me know. sounds like your wanting to do the same thing I did.

One question though. is your car an automatic or manual??? GOOD LUCK!

CamarosRUS

I have been converting to carb for a couple years now but each day get a better understanding of how all this stuff works. Mine was a SD TPI so yours may differ but if you need anything else ask.


I know it is extremely confusing but make sure to separate your issues/questions and not let everything jumble together or it will become even more confusing.

choekstra17

ok here are my questions if you can help

1) mine is a speed density and i am keeping my in tank fuel pump and puting a return style regulator to bring down the pressure. the question is can what do i do with the EVAP lines going into the tank. I want to remove the canister.

2) give em a general write up on the whole wiring harness to the computer removal or modification to make this carb motor and all guages work properly

Basically let me know what you have done and what i need

CamarosRUS

I had relocated my battery, used an aftermarket fan setup, done away with cruise, and have no heat or A/C so I will try to negate those aspects when I help you. Plus, I lengthened and shortened all my wiring to run it out of sight.

Fuel System:

The feed and return lines from the tank need to be hooked up the the bypass/return style style regulator. The third line is the vent line and I simply cut it off underneath the car and pinched it slightly to keep big things out of it but let it still vent. I need to find a better way, however.

Everything else hooked up to the vac canister can be cut and removed. Remember, while it takes longer, it is better to completely remove any wire you are doing away with from the entire harness. This avoids confusion down the road (which you will have). Trace it back to the bulkhead on the drivers side firewall. One exception is if you intend to use that wire for something else...I had saved my washer solution pump wires and will run these to a siren so when I hit the washer solution button it will make a hidden siren go off (shits and giggles).

The fuel pump relay gets its power from the alternator charging lead (Orange/Red wire by your battery). This is also the same lead that gave your ECM power and has a fuse inline with it. This can stay but you will have to cut the wire coming from the connector to the ECM.

There will be a green wire with a white stripe running to the fuel pump relay coming from the ECM. You can cut this as it normally tells the F.P. relay to "prime" for 2 seconds. The gas in your carb bowls will start the car in your situation. To keep the pump running with the car running is the oil pressure switch located above the oil filter. This switch acts as a backup for the F.P. relay by keeping the fuel pump running if it senses over 4 psi of oil pressure (in case your relay fries in the middle of traffic). In your situation it will be your main source and is not the best way but easiest and should suffice. I also ran a switch to the green and white wire I cut from the ECM to the F.P. relay so I can turn on my pump at any time I need.

Ignition:

You will need a new dizzy (I used a large cap for ease) and will need to locate the positive wire that will attach to your dizzy coil. This is the pink one in the harness. The other wire you will need is the tach wire hooked to the negative side of your dizzy, this wire is white from the factory. The other wires that used to run to the stock ignition system can be done away with.

MISC:

You will need to keep the wires going to your starter (the fusible link wires) as those wires run power to the interior and ignition system.

As far as you fans I am not sure. I do not know how much of the computer controls them as I know the ECM has a part. That's why I went aftermarket.

Of course, all the other wiring dedicated solely to the fuel injection in the engine bay can be removed. Map sensor, injectors, TPS, IAC, knock sensor, O2 sensor, etc. Most all the wires running to the passenger side can be done away with while the drivers side wiring powers your lights and horn (one side of the C100 bulkhead). The other wires running to the drivers side lead to the gauges and also include those power feeds from the starter (other C100 side).

You will not have a working speedo since the purple and yellow wires running to the tranny that feed the speedo run to the ECM first. A VSS buffer can solve that but it is complex. The other wires running to the tranny are your reverse lights and need to be left.

Leave the alternator wires alone.


There will be questions I'm sure but this write-up should get you most of the way along. Take your time, take notes, and make sure you double check before you cut!

choekstra17

Thanks, thats a big help!!!