94 Lifted Silverado 6.0/4L80e swap Build

[myzterray]

I will have to get u a pic for the rear vss. I don't have my pns switch wired up bc my truck is a 94. Is ur 4wd working? I can explain how I did my rear vss on the tcase but I think pics will b better. I cut nelsons rear vss connector and cut my obs connector . I took nelsons purple wires and put it with my blue wires I think from the obs. Then I took nelsons green wire and put it with the obs green I think. Then I put the stock obs connector on. So u will have two wires goin through a butt connector to one wire and then two. Wires goin through a butt connector to one then the obs connector

my 4wd wont work because i cut off the plugs that connect to the front driveshaft accidentally.

[HPICamaroSS]

my 4wd wont work because i cut off the plugs that connect to the front driveshaft accidentally.

K heres 2 pics of how I did mine. The blue and purple wires in the nice clean wire loom is the LS rear vss wires. Then the dirty wire loom is my stock wires with green and blue I believe. Don't mind the red wires, those are for my neons. I have a question for you, what OBS wire(s) did you hook your LS speedo wire to?

[HPICamaroSS]

Got exhaust ran today! And driving it to the shop I had a few problems (including blowing the water pump).

Hopefully I can get a few answers for my problems:

First, when the truck has been driven for a while and is up to temperature, i come to a stop sign and it will want to keep going and if i press the brake to try to stop it it will act like its going to stall out. So I have to put it in neutral. But when its cold i can stop and it will idle just fine with me on the brake.

Second, I cant get my speedo to work. I have tried hooking nelsons green speedo wire to my Light Blue w/ white stripe wire and nothing happens.

Third, my RPMS are way off. The tach is reading 1,000 when I am going 55 (using gps). Keep in mind I have 4.56 gears lol so I know that isn't right.

4th, when trying to confirm the RPMS with a scan tool hooked up to nelsonss obdII port, it says it can not communicate with the ecm. And the check engine light thats on their obd connector is lit up so I know it has power.


Other than those issues and the water pump, the truck drives like a dream. seems so smooth and takes absolutley no effort for it to take off. pulls really good on the top end for sure. its way stronger than my last cammed out crate motor. Ill get pics of the exhaust job, it looks really good i'd say we did a pretty good job going from the headers to a y merge pipe to a electric cut out to a single in flowmaster to dual out.

[RPM Graphics]

don't know how much help i can actually be since you have a 94, but on my 96 i have 2 wires coming from the c100 connector that both said vehicle speed signal, B5 & D4. one is green & the other green w/ white. the speedo wire coming off my nelson harness is green w/ white so i connected to my green/white & no speedo. connected it to the solid green, which is B5 & now my speedo works.

on the tach mine is doing about the same. it doesn't move till i hit about 3k RPM, then it only reads 1K. i saw myzterray used a 680 ohm resistor. i found 680k ohm & 680 ohm so i'm assuming it's just the 680 ohm. i'm going to hit up radio shack & see if i can get one & what happens.

i had a friend of mine come over with 2 scan tools. one really nice windows base & it worked fine. he also had a Mac & the Mac wouldn't communicate with it. i rented a code reader/scan tool from autozone this morning & it read just fine. the Mac tool also wouldn't communicate with another friend of mines harness.

hope you get your problems fixed. to me, all the final small things are harder to solve then getting the motor in everything mounted. all i have left on mine is the tach & all my factory gauges will be working, including the SES light.

[bobbylog]

First, when the truck has been driven for a while and is up to temperature, i come to a stop sign and it will want to keep going and if i press the brake to try to stop it it will act like its going to stall out. So I have to put it in neutral. But when its cold i can stop and it will idle just fine with me on the brake.

Did you wire the brake switch signal to the pcm...? The PCM need a 12 v when the brake are not being applied (the opposite of a standard brake light switch) This signal control the torque converter lockup.

[HPICamaroSS]

Did you wire the brake switch signal to the pcm...? The PCM need a 12 v when the brake are not being applied (the opposite of a standard brake light switch) This signal control the torque converter lockup.

How do I do that? I'm sure thats the problem because I havent done that lol

[bobbylog]

How do I do that? I'm sure thats the problem because I havent done that lol

I have never do that to but from what I've read you need a switch like this.
http://www.ebay.com/itm/TCC-BRAKE-SW...item27c42fbcc4
http://secure.ultracart.com/catalog/...f/KIT-1002.pdf
I've read that you can use a relay to but in my case I will just buy the switch.
Your nelsons harness is supposed to have 1 or 2 wire ready to hook to the switch.
Edit:

For automatics with lock up converter, the PCM needs signal when brake pedal is pressed. However, the signal needed is opposite how you're brake lights work. The PCM wants 12v+ constant on this wire when brake IS NOT pressed, and OPEN Circuit when the brake IS pressed. If you vehicle was equipped with a lockup trans to begin with, you probably already have the proper normally closed switch mounted by your brake light switch. If you do not, you can use a relay to perform the same thing. On most relays, there are 5 terminals, 2 of them turn the relay ON when provided ground/power. There are then a normally open leg and a normally closed leg on the relay and a supply. By feeding 12v+ on the supply leg, and hooking the Brake Switch Signal wire to the normally closed leg, you will now have the correct signal for the PCM. When the brake is pressed, 12v+ flows to brake lights, tap into this wire, and run it to the relay to turn the relay on. This will cause the normally closed leg to become open, thus turning OFF the 12v+ signal to the PCM. When you release the brake pedal, the relay will turn OFF, and then feed 12v+ to the PCM.

From Lt1swap.com http://lt1swap.com/wiringharness.htm
So you are supposed to already have a brake switch like this.

[92 6.0]

How do I do that? I'm sure thats the problem because I havent done that lol

Its real easy. Just find the brake switch in your truck. Its on the pedal up under the dash a lillte bit. And then look for the purple wire and splice the one from your swap harness to it and your done.

[HPICamaroSS]

Its real easy. Just find the brake switch in your truck. Its on the pedal up under the dash a lillte bit. And then look for the purple wire and splice the one from your swap harness to it and your done.

Do you know which wire I have to splice it into on Nelsons harness? Because their harness is a 4 wire hookup, and that doesn't include a wire for the brake

[RedHeartbeat]

Sounds like you need a resistor inline with the tach module. There is one year of pcm that has a very weak signal to the tach. Do you know what year your tune is from? Is it dbw?