1994 GMC Sierra Ls Swap

[RolandoLowko]

Should have been coming out of the engine harness right by where your coil/pickup wires came out. If for some reason you can't find it, it's pin "T" on the cluster connector.

You think im going to have to add a Resistor on the wire?

 

[Jglew82]

It's usually the 03+ PCM's that require the 1k ohm resistor and 12v boost lead. Try yours straight up first and see if it works. You'll need to be sure the tuning in the PCM for the tach output is correct as well.

 

[RolandoLowko]

It's usually the 03+ PCM's that require the 1k ohm resistor and 12v boost lead. Try yours straight up first and see if it works. You'll need to be sure the tuning in the PCM for the tach output is correct as well.

So i got it to work but the RPM's are super low like at 200-300RPM

 

[Jglew82]

Can you see what your tach setting is in the PCM? If it's set to 8cyl, move it to 4cyl which is the default for LS engines. If that doesn't work, try this: http://www.lt1swap.com/lsx_tach.htm

 

[RolandoLowko]

Can you see what your tach setting is in the PCM? If it's set to 8cyl, move it to 4cyl which is the default for LS engines. If that doesn't work, try this: http://www.lt1swap.com/lsx_tach.htm

so i wired the Tach but its like 1000rpm off i rev it up the tach moves smoothly up you think im going to need to add that resistor?

 

[Jglew82]

so i wired the Tach but its like 1000rpm off i rev it up the tach moves smoothly up you think im going to need to add that resistor?

What I am saying is there is a setting in the PCM tune that calibrates the tach signal output to the instruments. You need to determine what that setting is. Do you have HPTuners, or know a tuner in your area?

 

[RolandoLowko]

What I am saying is there is a setting in the PCM tune that calibrates the tach signal output to the instruments. You need to determine what that setting is. Do you have HPTuners, or know a tuner in your area?

No i dont but the tuner said it was set to 4cyl mode

 

[Jglew82]

Gotcha, try the resistor according to that link I posted above and see if that helps.

 

[RolandoLowko]

Update: driving the truck around Running like a champ i ordered the 12551708 Ac Delco 3 wire temp sensor getting it today

 

[Uncle Ben]

Great work man. Must be a hoot to drive