After driving about an hour, at a stop light I noticed the car trying to take off by itself, I thought maybe i had my foot on the gas at the same time as the brake, so at the next light I watched the tach, and it went a little eratic and jumped up to about 1000, held for a second and went back down. the ac was off. It has done it about 5 times and hasn't set a code. It seems like i hear a relay sound from under the hood when it happens but I'm not sure. I'm thinking either the iac is going bad or tps. Any ideas?
Richard

 

Vacum leak? Reset the IAC? Clean out the throttle body?**very bad issue for me YUCK**

 

I think Blackies's right about the vacuum leak. TPI is bad for it. I'm surprised it has not yet triggered a 32 code - EGR - which gets purged about every 10 minutes. Failure to hold vacuum will trip the 32.

How many miles on the motor?

 

about 110k

 

Sticking pintle in the IAC is possible. TPS? I bet not, since you say it 'loped', as opposed to constant increase rpm's. My $$$ is on an intake leak somewhere between the TB and the intake manifold...

It's a pain replacin' the intake gaskets, but cheap.