ad53030

Well plans changed and instead of getting the 4.8l I planned on I got a deal on an 07 LM7 5.3 & 4L60 w/ 7k miles from LKQ. Motor has full wiring harness, computer, all accessories, dual elect. fans, etc. I will have lots of issues but here are the first:
I am trying to not have to fork over another grand + for a custom harness. Looked in stickys, posts, etc trying to find some wiring diagrams/schematics on this motor. Any suggestions, books, etc? Any fairly cheap companies out there make a retrofit harness or modify this one? I need to save some $$$ here if I can.

Also I told them I needed the gas pedal and control module (DBW) for it. I got the pedal and the pedal harness but they said there was no control module there. There is a small, very thin module in the back of the engine harness. Could this be the control module for the pedal? I planned on getting an 03 motor and obviously they changed a few things from 03 to 07.

What about the return fuel line on this motor? I planned on using the C5 fuel filter/reg b/c I was told 03-up had a single fuel line w/ no return. Obviously that was wrong too. Do I need to keep the return line setup like it is? Do I need to run it from the engine back to the sender? Which filter should I run?

Thanks!

Jones'n

There are companies that will modify the harness you have, I know Current Performance will do it.

You do not need any extra modules for that year engine, just the engine computer and gas pedal.

There should be no return line on an '07, you should be able to use the returnless system like you had planned.

team39763

iTrader: (3)

Maybe you should PM or email Allen over at Nelson Performance. He does harness work and he's not too far from you(San Antonio). Even if you don't buy a harness from him, he could probably give you some good advice on what to do.

ad53030

Is this not a pressure line and a return line? Pressure line is steel hardline & return is the green cap & black plastic hard line.

pdsq98gt

The plastic line is you evap line. It routes fuel tank vapors to the engine and that solenoid is pulsewidth modulated and lets the vapors in when the pcm tells it to.

ad53030

So I just run this to the vent line on the sending unit then and it should function correctly?

ad53030

I'm using an 87 Chevy FI sending unit. The vent line is for a 3/16" hose. The 'vapor' lione on this 5.3 is 3/8" line. Will it matter to the solenoid/computer if I mate the 3/16 line to the 3/8 line?

ad53030

Trying to find out what you guys have been running for this vent/vapor line? My engine's an '07 5.3 from a Silverado into 84 C10.


I'm using an 87 Chevy FI sending unit. The vent line is for a 3/16" hose. The 'vapor' lione on this 5.3 is 3/8" line. Will it matter to the solenoid/computer if I mate the 3/16 line to the 3/8 line?

pdsq98gt

I don't think it will matter. As long as it's hooked up. That line needs a vent valve and charcoal canister between it and the tank though.