LS1 5.3 swap into 1957 Chevy pickup HELP PLEASE!

[Pinkcliff]

To make this post as short as possible. I used a 2001 Chevy Suburban 5.3 with 4l60e trans in a 1957 Chevy pickup.  Here is my problem I can’t seem to fix.  It loads up when cold or going up a hill.  The transmission shifts way to fast and down shifts way to fast.  The codes I get are MAF, TPS, and O2 sensors top side as bottoms are deleted.  I have replaced all sensors now 4 times.  Still the same problems.  My fuel pressure is 60 psi, I had the computer flashed with delete on both egr and bottom two O2 sensors.  It is drive by wire and I have replace the pedal as well.  I am sure this is something to do with the computer taking to all the sensor and trans to shift when needed etc.  Any ideas of what I can do to make things work correctly.  Also, one more thing, when the engine has been running for a while and you shut it off and let it set for 20 mins and go to start it up again, it doesn’t start right up like when cold.  Maybe I have a fuel issue as well.  I deleted the 3rd line from the fuel rail to the tank and have only high pressure side coming in and the return line back to tank.  Maybe I am getting a vapor lock some how…??

[eaglescout526]

You know this is a forum about the Jeep Comanche MJ right? Wouldn’t you want to be on a GM forum?

[89 MJ]

I’m guessing it’s an issue with the computer tune. Did you get theLS computer tuned or did you run a difference ECU?

[Eagle]

Not MJ-related, so moved to The Pub.

 

[FrankTheDog]

A good place to ask your questions and possibly get good answers is ls1tech.com.