[jm8881]

Well, I had to remove the v8 from the truck to fix a low oil pressure problem and I decided to just rebuild it again to make sure everything is hunkydorry. The truck was orrigionally a 93 4.3l vortec 4x4. I've put a carbed 350 into it and a 700r4 trans and now I would think that a lot of the wireing under the hood is unnessasary. Only thing is, I don't have a fsm to tell me what the miles of wire actually do. I seen a couple pictures of others with an almost empty engine bay, I'd like mine to be that uber clean. Thanks.

 

[meeh350]

while its out... pull the computer harness out of the fire wall..... trace everything back to the bulk head connector...... does it still have a PCM or ABS? if so life will be more complicated
trace the stuff to the bulk head connector and anything that goes to the computer can be removed....

when you put the 700r4 in... did you rewire anything or did you just plug the factory wiring into it........ if you just plugged the crap into it you probably havn't had overdrive.... the TBI ECM controls the TCC....... you can wire it to a switch and control that with a switch though....

might be handy if you told us what you did when you put the v8 in

 

[jm8881]

The pcm is still in it, it had abs, but I removed the abs module and replumbed the lines. Almost all the wireing for a 93 4x4 4.3l vortec is still in there minus the wires for the stock sensors. The 700r4 isn't in yet. I was going to wait and break in the v8 with the 4l60e and save some money to get the 700r4 rebuilt. But since I had to take the v8 out I decided to pull the whole drive line out.

 

[meeh350]

i could be wrong but i think your going to have to hook the TCC (lock up) to a switch and i would think you can remove the PCM... i could be wrong... i dont remember what all that controls..... i put a 4.3 in my truck and left that out of the swap ... but its a differnt situation for you.... if you have a friend with a similar year see if he will unplug the PCM and drive it for a while see what it affects... im pretty sure it doesn't control the gauges yet for that year..... the new ones have BCM that controls airbags and all the other crap but not yours.... im pretty sure it was for the 4l60e only

basically anything that goes into the computer can be removed all the way to the bulk head connector... most of them will go to sensors for the computer, majority of the stuff at the bulk head connector is power supply, grounds, crank wire, alt wire, gauges.....

question...
do you still have factory fuel pump setup?
if so did your rewire the pump relay?
is the ecm still plugged in?

 

[jm8881]

question...
do you still have factory fuel pump setup?
if so did your rewire the pump relay?
is the ecm still plugged in?

In the begining I was going to use the factory fuel pump but it would shut itself off after about 5 seconds of running. So I got a Holley Blue pump and it draws through the stock pump. But that doesn't seem to be able to keep up. Maybe it can't pump fast enough through the stock pump. I do have the stock pump disconected but left the lead for the fuel gauge so it still works. I think I'll just get a Mechanical pump and either an old carbed s10 fuel tank or get all fancy and get a fuel cell and put it in the rear cargo space to keep it away from the ground and give me more room back there. The ecm is still plugged in, I thought it controlled the shifting of the 4l60e so I left it in.

 

[meeh350]

my god, lots of codes in that ecm.......
reason why your fuel pump shut off after five seconds is...... no oil pressure switch and no rpms..... if the ECM sees zero oil pressure and/or rpms it shuts off fuel supply via cuts power.....this is where i was going with my questions

just wire the fuel pump relay ignitor wire to an ignition source or a switch.... the factory pump will work good then

yes the ecm does control the 4l60e .... problem is it sees no engine rpms and all that crap..... so probably didn't operate too well

 

[jm8881]

yes the ecm does control the 4l60e .... problem is it sees no engine rpms and all that crap..... so probably didn't operate too well

Never got to drive it because of the low-no oil pressure. So I don't know how the trans worked.

 

[meeh350]

it may have worked but i doubt it would have worked how it was intended to.. the ecm uses throttle positon, vss, and rpms to decide gear and torque converter lockup....... ecm had only vss so it would have been all confused.....

 

[bol]

mech350 is right
you need to have the TCC circuit complete, if you're not running an ecm you'll have to get an aftermarket harness or make your own
jegs has a bunch at http://www.jegs.com/cgi-bin/ncommerce3/CategoryDisplay?cgmenbr=361&cgrfnbr=929

you need to use one otherwise you'll burn the torque converter up in overdrive