Defender LS3 swap - accelerator problem

[83DefenderLS3]

1983 Defender with an LS3 swap. I’ll be driving and accelerator will stop responding. Its a manual and if i leave it in gear the idle will roll it about a mike an hour( on a flat road ). Turn the truck off for a minute and I’m guessing computer resets because the pedal responds when I fire it up. Drive along until next occurrence, which can be an hour or a week. Maddening to say the least.

anyone else have this problem with a 2016 LS3?



guess at a diagnosis ?

[Hotwire]

Need to pull the wiring harness apart going from pedal to TAC to throttle body. There's probably a bad connection somewhere in between. You might can get a scanner on it and pull codes to see if anything is reporting. Might make tracking the problem down a "little" easier.

[83DefenderLS3]

Replaced the throttle body already and the problem continued . I’ll follow tour advice and see about codes.
Anythoughts that it could be the ECU and not just a short ?

[Hotwire]

It honestly could be anything. I misspoke above, the Gen4 motors do not have a separate TAC module, it's built into the pedal. So you have 3 components. ECM, pedal assembly, or wiring.

Are there any common parameters happening when the pedal goes away? Temperature, run time, engine load, gear, etc?

Do you have a way to datalog? I'd suggest key on/engine off datalog the throttle and start wiggling wire harness from pedal to ECM to TB to see if you can force it to lose connection. If it doesn't then it may be time to try hardware, but assuming your harness is custom, that's where I would start.

[83DefenderLS3]

Thanks Jeff. I am greatly appreciative. I’ll get to work and post when i’ve solved it.

[andrewb70]

Are you using an OEM ECU? That's a gen 4 engine, so there wouldn't be a TAC module.

Andrew