k5383

iTrader: (10)

Well, picked up a LQ4 tuesday complete with harness and PCM.

02 motor 03 PCM.

Had today off, stripped the harness off... labeled everything accordingly. With the exception of these few plugs...

I assumed trans?

This one is up closer to the Red/blue connectors..


I then followed the instructions/directions on the following link to make it a "standalone" harness. I'm running an old 4 speed. So I also removed anything that had to do with the electronic transmission.

http://www.lt1swap.com/99-02_vortec_pcm.htm

My problems...

I removed all the pins as instructed, however (unless im retarted) for example 1/2 of an A/C plug is now unwired, whilst the other half is not. Same is true for another plug as well.

The VSS was retained as well.... does this NEED to be retained? I'm going to be using mechanical gauges, and a mechanical speedo, no cruise etc.

So, my main questions:
What are the above plugs?
Required?
On the C2 plug there are a whole lost of pink power wires, how many are needed?

Thanks in advance... I've been slowly working through this thing the last 6 hours... back hurts and I'm almost blind now.

k5383

iTrader: (10)

Had a thought as I was in the shower...

I already have 19,75 (switched) seperated from the harness
and 20,57 (constant)

Since thats the case, can I just cut the remaining pink wires from the C2 plug?


So, Im considering getting a piece of plywood, spreading the whole harness seperating each branch via wood/nails etc. then just working sensor to pcm pulling the wires/sensor that aren't needed.

Aside from coil, injectors, front 02, cam, crank, throttle body (drive by wire for now), map, IAT, is there any sensors I'm missing?

Is switching from DBW to DBC much more difficult than puling the DBW wires, and switching throttle bodies?

FastKat

iTrader: (10)

The first two plugs are the trans plugs. They both plug into the PNP (Park Neutral Position) Switch. The smaller one with the red gasket tells the PCM what gear the shifter is in. The larger is used for your backup lamps and starter-safety switch, which only lets your car start when in park or neutral.

When you say old 4 speed - that's a manual, right? If that's the case, the red connector one can probably be removed. The other two sets of wires should be routed somewhere... the starter safety switch will probably somehow be relocated to the clutch, and the backup lamp wiring will probably be relocated to somewhere on the trans. I know the T56 has a plug for it - not sure about your 4-speed.

I am not 100% sure, but I think the pink wires on the C2 plug have something to do with the injectors. I consolidated mine at the fuse box. I am not 100% sure about the C2 thing - maybe someone else will chime in.

dec010974

iTrader: (1)

hello K5383. some ls1tech members remove the pins and the unneeded wires. i just taped the unneeded wires to the harness. i made sure the wires were out of the way to avoid hang ups and connencted the necessary external connections like fuel pump trigger, fan triggers, vss and so on. to me, you can never make a fuel injection harness look like a carbed wire set up,too many sensors/connectors. just my two cents.

FastKat

iTrader: (10)

Oh yea, and that connector in the second picture (the larger one) plugs into the TAC module. That is part of your DBW setup - it is an interface between the throttle body, PCM, and gas pedal.

I would stick with DBW. I've never done it, but converting to DBC looks like a PITA - just my opinion. The truck DBW stuff is pretty plentiful and generally inexpensive. If you need a DBW throttle body, I have one I'd practically give to you.

k5383

iTrader: (10)

I know the harness won't look like a carb harness. Thats no big deal to me, in fact I'm going to use most of my factory carb harness grafted into this one to make the whole thing quite simple.

By old 4 speed I mean SM465, its a truck 4 speed. Any reason I can just ground out the NSS?

I kind of figured switching back to DBC would be more simple, interesting you made that point. I've already got the throttle body, but thanks for the offer.

Guess I need to hit up google some more.. ha

zipster

iTrader: (5)

I put my engine on an engine stand, connected all the plugs to where they should go. routed the o2s, and the vss.











Route the harness where you want the computer. Add wire to the ones that dont make it, shorten the ones that are too long. Solder, and heat shrink all connections.

k5383

iTrader: (10)

Since im running all mechanical speedo, I wont need the VSS correct ??

G-Body

iTrader: (4)

You don`t need the VSS, but it will run better with it. Some people have reported no issues with eliminating it, others report stalling when coming to a stop and other driveability issues.

Converting from DBW to DBC is kinda a crapshoot. It might be easier to put in a throttlecable and go, but many of the newer green/blue PCM`s do not have IAC drivers in which case you have to chase down one that does, or more likely repin the harness to run an older red/blue PCM.

psiconversion

iTrader: (5)

Gbody is right. Most Green/Blue PCMs dont have IAC drivers. You should probably switch to a red/blue pcm if you are going to make the move to drive by cable. Also, if you are going to make the switch, you may want to consider selling your dbw harness and starting with a drive by cable harness. Just a thought.

Jon
PSI

k5383

iTrader: (10)

Good point, its a red/blue harness but a red/green pcm... hopefully it wont create any problems there..

99VetteFRC

If I am correct... 02 engine is DBC and the 03 is DBW.... I can email both schematics sets to you if you PM me your email address. Get the 02 PCM and harness IMO.... I read it's somewhat tricky to get pedal and TAC and ahve it work right. Good Luck.

k5383

iTrader: (10)

Alrighty... ive got the harness stripped of all the unneccessary stuff.

Beginning to cut/solder to make it look cleaner...


Is there ANY reason why I can't cut all the grounds, and solder them all to each other, essentially making it a running ground. Of course with as many external eyelets as factory.

Also, same question for all the pink wires, any reason I can't consolidate them together and run a larger gauge up to them?

Example: drivers side injectors/coil, wiring them all together then have a single wire feed them.

FastKat

iTrader: (10)

You can consolidate the pink ones into larger gauge wires. I did it and it seems to work fine. Also, I think GM did this with some of their later LS vehicles as well.