Fuel guage problem post swap

[99suburbswap]

I just finished a ls 5.3 in my 99 suburban and now my fuel guage is pegged on full anyone have any idea's what I need to do to fix it?

[Lextech]

You didn't mention which PCM is controlling the fuel gauge. If it is the Gen3 PCM and is wired properly then the tune is not correct.

Jeff

[99suburbswap]

You didn't mention which PCM is controlling the fuel gauge. If it is the Gen3 PCM and is wired properly then the tune is not correct.

Jeff

Sorry yes it is a gen 3 PCM out of a 2000 pickup. I've had a horrible time with the guy that did my harness and my tuning. So now I'm trying to just complete the swap and I have issues with it starting it stumbles much like it off timing then after it starts it's rough for about 30 seconds then smooths out. Not sure if anything about the tune is done right.

The first PCM he supposedly had it tuned when he sent it but it wouldn't start. Finally after 2 weeks of back and forth emails he came up here to Michigan to do what he told me was a crank relearn but told me the PCM had checksum errors on it. This was the one that came with the engine 2006 lm7 he gave me a PCM from a 2000 chevy and supposedly tuned it but now all this sigh! Makes me wish I would have just bought a 350 to replace the original engine.

[1991SSP]

here is the correct answer that LexTech gave me on my swap on my 98 tahoe

The Purple wire goes to PCM C2-38. The Purple/White wire goes to PCM C2-54

[99suburbswap]

here is the correct answer that LexTech gave me on my swap on my 98 tahoe

The Purple wire goes to PCM C2-38. The Purple/White wire goes to PCM C2-54

I will go look at it and correct it thanks man.

[99suburbswap]

There's a problem it has 2 purple white wires I changed the two and didn't get any change I'll swap the other tomorrow

[1991SSP]

let us know what the result is

[99suburbswap]

I have not went out there to do the wire swap yet cause it having 2 purple white stripe wires the jack*** that did the harness screwed something up and is avoiding me for over a week now. Side note avoid rusted customs in Ohio guys name is Charles. Unless you like poor communication faulty programing and possible messed up wiring. Sigh! I just wanna drive my truck.

[1991SSP]

PSI or Nelson's is the only way to go for wiring.........

[99suburbswap]

Well after a long troubled mess I finally have the truck running and driving smooth thanks to lextech for the help and the programming still have yet to get the fuel guage going but now that it's running good I will find the correct wires