phishincruisin

I have a 5.3L and I think its an '04, but it might be an '03. What is the easiest way to tell? I was told it came out of a Silverado, originally an '02, but with the blue and green connectors, it has to be an '03 or later. I have the '04 1500 Silverado wiring diagram and went through all of the wires on the PCM I found that on the green connector, I have a blue wire in pin 33, and my wiring shows no wires in pin 33. Everything else seems to line up, except pin 54 on the green, it is ppl/wht rather then the ppl it says on the diagram.
I've searched this site and others, and have tried to use any numbers I can find on the block, but haven't had any luck. Any help is greatly appreciated! And for all you that are curious, this is going in a '85 Toyota Land Cruiser

poconojoe

iTrader: (43)

If you have the PCM that belongs to the motor, just read the vin out of it

phishincruisin

If I had the PCM this obviously wouldn't be a issue. I don't have it, and I'm missing some other components which is why I'm trying to figure this out

Bo185

Not any difference physically between an 03-04. Now if it has an EGR valve them its a 02.

The diagrams very on model as well, but its not that big a differance. So it shouldn't matter as long as you figure out what you need don't need then ID the wires. If you have one or unknown just chase them down and see were they go and if you need them or not.

phishincruisin

Thats what I was thinking I might have to do. I'm just thinking about when it comes to tuning my PCM, will it not matter which year it is? I know the '03-'07 PCMs are interchangeable, so I'm trying to get my hands on one of those.

Just to make sure, there isn't anything going to the auto tranny that I will need to keep since I'm making a stand alone harness to go with the stock manual tranny. There are some wires in the plug that goes to the PNP switch that I'm not sure about. I can't find the pinouts for them everywhere. Maybe I'm just trying to figure things out too much before I start pulling the wiring apart...

phishincruisin

Also, when did the truck motors switch from having a return line/regulator at the fuel rail, to having a return line/regulator off the block? I don't see any evidence of a regulator/return at the fuel rails. It looks like the fuel comes in on the drivers side, and splits and goes to the two rails. the fuel line goes over the intake manifold to the passenger side fuel rail.

PedaltoMetal

03 still had the regulator and return line at the rails. 04 moved everything to the filter.

spacemanspif

iTrader: (5)

I haven't run the VIN on my block but I was told from the guy I bought my engine from that it was out of a 04 Tahoe. It has the return line on the fuel rail and a drive by wire throttle body. I was under the assumption that 04 is when they switched to the DBW throttle body.

1quickirocz

they went to dbw in 03. as far as the regulator and all that i think the diff is whether its a flex fuel or not. VIN would either be T or Z. pretty sure the Z is the flex fuel which i think only has the fuel feed line.dont know if that helps anything but anyways...

phishincruisin

Do the flex fuel motors have different injectors? any other ways to tell if it is flex fuel or not?

Bo185

In 05 the trucks went returnless, 03 went DBW, some (Vans mainly) were still cable and some had of those even had return style intakes.

The Flex fuel motors have larger injectors 32# IIR.

https://ls1tech.com/forums/conversio...ences-e85.html

1quickirocz

i think the connectors are diff but i couldnt tell you how to id them. if you have a return line then i think you have the non flex fuel vin T engine.

busta9876

iTrader: (3)

From the very first post: your blue wire on pin 33 of the green connector, is electric fan #2 relay control. You should also have a wire on blue connector pin 42, this is fan #1 relay control.

Looking at a bunch of my stock calibrations I have, fan control was not a factory enabled until 2005.

flippincamaro

iTrader: (23)

As for the drive by wire comment, Thats not true, 03 wasnt when they came with dbw my 2000 5.3 tahoe is drive by wire factory, I just replaced the engine in it with a 04 model engine.

busta9876

iTrader: (3)

true true, a small percentage of the 99-02 were drive by wire, with RED/BLUE connector harnesses. I'm not sure what specified a vehicle being drive by wire, but mostly i've seen SUV's, and higher end models with it. Also, all vortec 8100 were drive by wire, and all Corvette's back to 97. There was also a Vortec 7400 454 that was drive by wire in 2000, in medium duty trucks, they also had coil pack ignition on this 7.4L engine.

in 2003 ALL trucks were drive by wire, except Express Van.

The 2002 prior electric throttle bodies had a 2 separate plugs, the 03+ drive by wire throttle body was all in one plug.

PedaltoMetal

Injector connectors are different. But some Flex Fuel engines do have a return line. I have a 03 Flex Fuel L59 with the regulator and return line on the rails.