ok, i'm finally getting around to removing the computer wiring from my 89 rs (305 tbi). i've been running a carb setup for about a year now, so i know it works. what i need to know is what i have to now rewire since the harness will be removed.

i am keeping the intank pump, so i know the pump relay needs to be redone (or at least a wire or two)

i dont care about VATS, so i know that can go

how about the oil pressure/fuel cutoff switch? keep (and how) or get rid of it?

distributor should be fine, or are the leads to it from the pass. harness?

i noticed the few sensors on the a/c setup. anything to worry about?

finally, i noticed quite a few +12v wires coming from that harness to the starter. do i need to keep em?

i know theres a few questions and i have searched for answers, but coming up kinda dry. also figure it may help someone who's in a similar situation.

 

ok, i have a couple answers to my questions. sorry if i'm quoting anyone, cause i figured i'd cut and paste if anyone else is reading this thread.

Fuel Pump-
"From the relay, the thick Orange wire runs to the battery (constant power), the thin
Black/White wire is the relay's ground, the Green/White is the relay's 12 volt source
(key on power), the thick Tan/White is the Fuel Pump Power wire (leading to the tank),
and the thinner Orange wire is the ALDL wire (fuel pump diagnostic check).....

The thick Tan/White wire (fuel pump power), and the thin Orange wire (ALDL wire) both
by-pass the ECM, then connect into different color coded wires through a clear connector
(on the connector, there found on terminals B & D).

If you're planning on keeping the ECM in-tact, then all that is necessary is to find
another 12 volt (key on) source for the Green/White wire coming from the Fuel Pump
Relay (which originally went to the ECM), as well as find another ground source for
the Black/White wire from the relay (which too was originally led o the ECM)....

If you pulled the harness out, and tossed the ECM, then the procedure is still
the same.... however, you'll need to re-route some new wiring to their respected locations."

i also know about the relay under the rear seat. this is another option.

VATS-
"Just the starter enable relay. Pull the driver side kick panel, there should be a relay.
It should have 2 yellow, 1 dark green/white, and 1 dark green wire. There a 2 ways to do
it, since you are probably going to leave the car this way I would simply pull it out.
Jump either yellow wire to the dark green/white wire and it should now crank. Thats it.
The other way if you want to leave the relay in is you can ground the dark green wire.
The relay should click then you are set to go. Wiring it this way will always have the
relay energized when the key is on. Either way will work, eliminating the relay is
probably best over the long haul but this should get you going."


ok, so how about bypassing the oil switch? i believe that will be eliminated if i decide to go the route of rewiring the pump relay located in the car as opposed to rewiring the one under the hood. any suggestions?

 

heh, not hard.

first, leave VATS... no worries there, its seperate from the ECM.

go under the dash, remove the ECM.. unplug it..

then unplug the harness... undo the fenderwell, and remove the harness from the kickpanel.

cover the kickpanel hole with somthing...then remove the harness from the fender....


basicly the whole thing comes out.. the only wire you should have to cut is the ECM battery power.. since it also powers the fuel pump and you want to keep that.





pretty simple..

the gauges, ignition power, and everything else you should be using, is off of the bulkhead connector on the drivers side....

 

this might be dumb but what is VATS?

 

Vehical Anti Theft System


the key of a VATS car will have a resistor in it (sometimes called a chip)

when the correct resistor is in, the VATS module enables the starter and sends a "alls well" signal to the ECM.

without the signal, the ECM does not fire the injectors.

 

Thanks

 

Where specificly should I wire the fuel pump to make it work properly when the ecm is removed?

 

it seems, from what ive found, that all you need to do is give the green/white power when the key is on. but i'm gonna go through my haynes/chilton manuals to double check

 

Run it through an oil pressure switch for safety's sake. A timed relay for starting, or powered through the "R" terminal of the starter solenoid (or is it "S"? I can never remember w/o looking - whatever, the one that isn't used to start the car) is a good way to get fuel up to the carb before it starts.

 

Awesome...I shall take a look at the stater solenoid...