TPS and Ethanol

[dagenham]

My idle has been acting dumb for a while now and I blamed it on the TPS I bought from Advance or Autozone, I dont reacall which. It would idle real high, 2k-3k rpm. And then the next time it would bounce around.

I started using Lucas ethanol treatment and I realized that my idle was not acting up any more. Now the last two times I put some gas in the car I forgot the treatment and twice today the car would not idle below 2500. I shut the car off and started it right back up and then it idled ok.

Has anyone else had any kind of issue like this with their car?? Here in PA it seems like all the gas is now 10% ethanol.

[MikeFleming]

Look for an EEC Code 23.

[dagenham]

Refresh my memory Mike, what is that code for??

[MikeFleming]

It is an on-board self-test code that the EEC may generate. That specific code relates to an open spot (or "out or range" value) in the TPS signal. Usually a defective TPS or a wiring harness issue. It could also also be a very tightly set TPS value with a worn throttle shaft that does not give repeatable closed-throttle values (varies with temp and manifold vacuum).

[Stinger]

Could also be a dirty IAC solenoid on the throttle body. They tend to "stick" and cause the idle to hang. Turning off the engine and restarting will "unstick" the IAC temporarily.

[dagenham]

Could also be a dirty IAC solenoid on the throttle body. They tend to "stick" and cause the idle to hang. Turning off the engine and restarting will "unstick" the IAC temporarily.

DUH! Why didnt I think of the IAC too!?
Thanks guys I knew someone would have an answer.