I always thought it was throttle related because i had a bug in my throttle map that would only randomly cause the severe lag where the revs increase extremely slowly. My guess is that the TPS or the throttle body itself would age or gunk up slightly. ECU figures commanded vs actual position isnt right so it goes into limp. After all, these cars emerged around the time of the Toyota floor mat scandal.
The thing that puts me off your overheated TPS theory although you have proof that i don't question is that from factory the throttle bodies are connected to the engine's coolant circuit to warm and stabilise their temperature. Largely to prevent icing but perhaps also to keep them from overheating. In their default location they are subject to coolant temps around 90*c and above, and also convective heat from the headers/cats beneath.
The Stillen kit places the throttle bodies on the hot side of the intercooler. I cant remember if the coolant plumbing is retained? So maybe the coolant really is there to keep them cool?
Personally, i think yours might be an isolated case where something failed and melted the wiring.
It's easy to upgrade this cable - wrap it in exhaust wrap and then some foil tape on top. Alternatively you can buy heat insulation sleeves for ignition leads which will do the job too.
|