bluto951

This only happens after the car warms and has been running for a good period of time so from what I have read that's a sign that it's the TPS right?

Also...is the best way to do a quick test is just to open up the throttle a bit and close it back down to idle slowly listening for the click correct?

Thanks

will951

I chased high a high idle issue for over a year. Vacuum leak is easy enough to check so start there.

With the TPS....my mechanic never found it because it would give a good signal at times (....unfortunately when he was checking it) and it was adjusted properly (the 'click' when pulling the throttle off stop position).

I was always suspect of the TPS.....so I bought a replacement and everthing has been perfect since.

bluto951

thanks...not many examples came up through the search so I am glad I am not the only one that had to deal with this...I'll check for the click first and then start looking for the vacuum leak ( I hate doing that)...and if I am lucky I'll have a spare TPS in that box of spare parts the PO gave me :-0)

will951

You can lightly spray carb cleaner or something around the vacuum lines....see if there is a change in the idle.

Mike Lindsey

It may be the connection at the TPS and not the TPS itself. Try moving the connector around a little while idling.

TurboTommy

How high is your idle?
Vacuum leak usually won't give you a high idle; more like a rougher idle.
A TPS, if it clicks, can still be bad, causing high idle
Also, if your throttle plate is too far open when resting against the stopper (or if it's gunked up a bit on the inside) will cause this; and yes, also more when the car is warmed up.

edh

+1 on the throttle plate - also check your throttle body & make sure the return spring is still there. These can go missing sometimes. The signal from the TPS is easy to check, but I'd suggest you do it when hot. I've found it can click off when cold, but not when hot. Clarks has the test procedure.

bluto951

thanks guys! all great advice. When it gets warm it usual gets up to 1400-1600 rpms max

edh

can you get it to idle back at normal by a sharp jab on the throttle? that sometimes works when the TPS is just slightly out of alignment.

951Tom

Check the round evap vacuum diaphram by the drivers side shock tower. Mine was ruptured and wouldn't pass a vacuum test. It caused my idle to go up 200rpm.

adrian1

The ISV might be leaking, I've people having the same problem on pelican. and the ISV had been the problem.

bluto951

ding tried that today and it went right down to 1k rpm....totally forgot to check it out when I got home...will hopefully have a chance to mess with the connector a bit this weekend.

Luis de Prat

I've had both of these things happen to my 951 and the difference here is that they don't wait until the car has warmed up. In both cases you get a hissing sound from the leaking part on a cold engine, whether it be the blue vacuum check valve or the ISV.

The OP's problem appears to occur only after the car has reached operating temperature.