LS Swap Complete - Stalls on occasion
09-29-2019, 05:52 PM
#1
Teching In
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LS Swap Complete - Stalls on occasion Just finished the LS swap in my 79 C10. I'm using a 4.8L from a 2002 Silverado.
Been driving a bit each day close to home to get it broken in and make sure I don't have any issues. So far, I've run into one issue. When I give it a lot of gas and then slow down, the truck will either drop RPM's way down to where it's close to stalling and recover OR it'll slow down and sound fine, but then it quickly shuts off with no stutter or anything.
Each time it's stalled, it's started right now. One of the times, it sounded almost like it was flooded a bit but then it fired up and drove fine back to the house.
I'm wondering if it's the tuning of the ECU that might be causing it. I did have it bench programmed. Has anyone else had this issue? Any suggestions on what to check out? THanks!
Been driving a bit each day close to home to get it broken in and make sure I don't have any issues. So far, I've run into one issue. When I give it a lot of gas and then slow down, the truck will either drop RPM's way down to where it's close to stalling and recover OR it'll slow down and sound fine, but then it quickly shuts off with no stutter or anything.
Each time it's stalled, it's started right now. One of the times, it sounded almost like it was flooded a bit but then it fired up and drove fine back to the house.
I'm wondering if it's the tuning of the ECU that might be causing it. I did have it bench programmed. Has anyone else had this issue? Any suggestions on what to check out? THanks!
09-29-2019, 10:23 PM
#5
TECH Senior Member
09-29-2019, 10:31 PM
#6
Perfect world - vehicle on a lift, get it goin, and get the two wires from the vss fed into a scope to see if you’ve got a sine wave output varying with speed.
What type of VSS did the 79 have? My 82 Volvo had a speedo cable - no VSS. I had to add one.
What type of VSS did the 79 have? My 82 Volvo had a speedo cable - no VSS. I had to add one.
09-30-2019, 12:54 AM
#7
Sounds like it might need some more idle air. Try cracking the tb blade open a hair via the set screw. U will need to do a tps/iac relearn afterwards. Thin see how it acts.
If this doesnt help, its most likely a tuning issue.
I just tuned today, a built ls swapped c10 with th350. Idled great without any stumble issues coming to a stop. Ecu doesnt even have the vss hooked up. It really all comes down to tuning!
If this doesnt help, its most likely a tuning issue.
I just tuned today, a built ls swapped c10 with th350. Idled great without any stumble issues coming to a stop. Ecu doesnt even have the vss hooked up. It really all comes down to tuning!