Where is the Throttle Position Sensor?

[89_Red_Festy]

OK, I've got an '89 Festiva w/ carb and would love to find where the heck the TPS is. If anyone has a related DIY, it would be greatly appreciated.

My problem is that when I let off the gas, the idle drops and becomes very erratic, to the point where the car stalls. I've been reading through the posts and would like to start with the TPS. Since Autozone can test it, I can either fix the problem right there or rule it out and continue looking.

Any further advice would be awesome too. Thanks

[mattswabb]

Is there one on the carbed models?

[89_Red_Festy]

That's what everyone keeps telling me but I sure can't find it anywhere.

[mechanicaldj]

no

only fuel injected models

[gdawgs]

Throttle position sensors are part of the Electronic Fuel Injection system. So your car does not have one.

1st, check for airleaks, maybe a loose fitting or cracked hose. A good way to test is to let the car idle(if you can get it to idle), then take a blowtorch and open the valve, but do NOT ignite the propane.
Then move the blowtorch around near the carb(leave the air filter on) and if there is a leak, it will draw in the propane, and the engine speed will increase.

If you don't find any leaks, pick up a repair manual, and follow the carb adjustment procedure.

[WmWatt]

The small canister in front of the carburetor with the four rubber tubes coming out of it is supposed to smooth that out. But that's not to say there is anything wrong with yours. Have you sprayed carb cleaner into the throttle lately and on the linkages around the outside? I'd try cleaning before messing with controls which are not well understood.

Another possibility is the idle speed circuit on the ignition control module in the distributor. That's just a wild guess. Fortunately it can be removed and taken for a free test at some parts stores.