Hi folks, I have a 300,000 mile Camry here with a problem that I would like to confirm. If the throttle is pressed gently, the engine rpm's will rise to around 2,000 then fall back to 1600 and the cycle repeats itself. I'm thinking most likely the TPS has a dead spot but I'd just like someone to chip in with either confirmation or perhaps a lead to another source of the trouble. BTW, the PO soaked the distributor while doing an engine clean but i'm not sure that this is related to the current problem.
Thanks in advance for your thoughts,

Chris.

 

You can test the TPS with an ohm meter through its working range.

 

Thanks for the tip Pedro, I'll give that a try and report back but even if there is a dead point on the track why would the rpm's surge in this way ? I would have expected a flat spot, perhaps the ECU is trying to compensate ?

 

I forgot to ask Pedro, which of the four wires do I need to scope ?
This car is a Dec 1991 fitted with the 2.2 litre 16valve motor.
Thanks again,

Chris.

 

Too involved to explain as you check all four terminals and use feeler gauge to check initial setting. Haynes has it.

 

No sweat, I found a web site that explains the procedure in simple terms.
Dead easy and only four tests to produce a result. Not exactly a black art form, just a matter of logic, why do you think it is so involved to explain ? I'll throw up a link for those that may need to go through the same pain.

thanks again for your help,

Chris.