LS1GMCTruck

iTrader: (2)

Without warning, without stumbling first, it just cuts out dead while driving around town at low speeds. Sometimes after idling at a stop light, it just dies...as if its a electrical disconnect or something. It is happening much more frequently also. Any ideas guys? Thanks, Gar

bczee

iTrader: (12)

Is it throwing any codes ?.. do you have a fuel pressure gauge to see if the pressure is dropping off ? How is your battery and charging system.

Get a scanner hooked up and connect some data or monitor it the sensors.

Did you change anything prior to this starting up !?

ghettocruiser

iTrader: (17)

What he said.. .Plus check out the grounds on the back of the head, as well as the power wires (pink ones) for all your sensors in the engine harness. With a engine like the LS1 that has quite a bit of electronics, it doesnt take much to cause issues.... Good luck!

Justin

rat_rod_russell

Did you play with the computer? if the Decel Fuel Cut Off (DFCO) is kicking in it cuts the fuel when the car thinks you slowing down and will have the system disengaged so it can save a little fuel. If your missing a sensor the DFCO might be kicking in prematurely.

01WS6/tamu

iTrader: (37)

If you used your OEM 1996 fuel pump sending unit I can almost promise you that is where the problem is especially if it has over 100K on it. If you pull it out and disconnect the wires at the very top where they connect to the pass thru connector more than likely the ground terminal will be discolored and where the terminal goes into the pass thru it will be scorched looking around the edges. These senders work fine for years but we have had a rash of the 96 97 trucks through the shop that people have put mutliple fuel pumps in, including us. I stumbled across this about three years ago on a truck I was at my wit's end with. Replace the sender it's about 175 from gm and you'll be good to go.

LS1GMCTruck

iTrader: (2)

Great feedback, thanks...I will look at all of these possibilities & report back. Gar

a10beav

I've had this problem too, but just when I decelerate to idle. My dyno tune fixed it for about a week but now it's back. Hopefully some of the ideas mentioned here will fix it.

a10beav

Can the DFCO be turned off completely or just modified somehow?

rat_rod_russell

With EFI Live there is no disable, like with the CAT protection and ERG settings, but you can go in and put impossible settings to keep it from kicking in like only enable after motor drops below 0 RPMs like that.

R^3