68 c10 5.3 (help)
Thread Starter
Staging Lane
Joined: Nov 2008
Posts: 70
Likes: 0
From: Cumming
68 c10 5.3 (help) Just got my swap done. 5.3 with ls1 intake 4l60e. My prob is it seems to idle great but when i get on the road under load it stumbles horribly under any throttle range, but if i floor it full throttle its like you flip a switch and it pulls hard and smooth as long as i am wot. Im not getting any codes. Any ideas i am dying to drive this truck.
It's probably something in the tune. When you floor it, it goes into PE mode and the fueling is different, hence the better running. Get it to a tuner, unless you do your own tuning.
TECH Fanatic
Joined: Oct 2011
Posts: 1,356
Likes: 2
From: Felton Pa
Sounds like mine the first time I ran it. Make sure the o2s are plugged in the correct sides. My car didn't throw any codes either and I got lucky watching the data and the O2s were reading wierd. I had written left and right on the plug when I did the harness so when I checked my theory was confirmed, swapped connectors and runs 100% now.
Trending Topics
the oxygen sensors have 4 wires going to them, of the 4, one will be purple. The sensor on the DRIVERS side should have a purple with white stripe, and sensor on PASSENGER side will be solid purple.
Are you using the truck mass airflow sensor?
Are you using the LS1 injectors? If so, which part#? (3 of them from 99 to 02)
What are you using for fuel pressure regulator. (vacuum referenced?)
All that info is very important when it comes to getting the computer programmed for your setup. If you did not provide, or were not asked that info, it could be incorrect and causing your drive ability concerns.
Are you using the truck mass airflow sensor?
Are you using the LS1 injectors? If so, which part#? (3 of them from 99 to 02)
What are you using for fuel pressure regulator. (vacuum referenced?)
All that info is very important when it comes to getting the computer programmed for your setup. If you did not provide, or were not asked that info, it could be incorrect and causing your drive ability concerns.
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine
Verdad Gallardo
7 Most Reliable High-Performance Engines GM Has Ever Built
Verdad Gallardo
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin
Verdad Gallardo
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
On The Tree
Joined: Nov 2010
Posts: 114
Likes: 0
From: Fairview , MO
I had the excact same issue. idled great, part throttle stumble/ miss ,at WOT it pulled like crazy. I got in contact with the guy who done my computer and he told me my 02 sensor wires were crossed. swapped them around it its a whole new car ,runs great. check into what Busta said on your 02 sensors he was the one that done my computer. unplug one of your 02 sensors at the plug and look at the harness wires there if the drivers side has a purple wire with a whit stripe then the 02 wiring is right if it has a solid purple they are on the wrong side.
