I have a 1987 oldsmobile cutlass with the 307V8. it has 60000 miles on it. the issue is the cold idle. during the Winter the idle takes a long time to kick down sometimes 25 minutes. warmer weather it is less. sometimes the engine light comes on and goes out after the idle kicks down. what would be some areas to look at to try to solve this problem

 

1 )The choke - make sure it's adjusted properly, and also that it's actually heating up and the air valve is opening.
2) The fast idle setting.

 

Unlike older carbs, the choke coil on the CCC Qjet carb isn't adjustable. There's a notch and keyway that locks the coil in at one position only (to prevent anyone from altering the stock settings and thus causing the engine to violate emissions levels). The coil does go bad, so replacing it wouldn't be a bad move.

 

As said, replacing the coil and gasket is a good move. I have also seen them go bad when working on these cars in shops and the choke doesn't come completely off. Is the heater hose still next to the choke coil? It should be in the clip, aids in the choke coming off sooner. I have also seen where the choke hot air tube rotted out in the intake. Also carb cleaner then lube on fast idle cam also helps.

 

I had some nice weather today so I worked on the Cutlass a bit more. I cleaned all the carb linkage and checked all the vacuum lines. All the lines seem fine and the linkage is clean and moves without issue. I started the car and it started without issue. It went to high idle. After five minutes I kicked it down which it did. The engine light came on so I checked the codes. I got a #13 (02 sensor stays low/lean) and a code #21 (throttle position sensor signal voltage is high during engine idle or deceleration). Other than the high idle the car runs fine. Should I change the TPS first or is this still a choke issue? I changed the 02 a few years ago so I think it may be fine and only be throwing a code due to the TPS code. Any thoughts would be appreciated. Thanks.

 

Disclaimer: i know little about these cars.

but i would investigate the TPS a little further. Can you measure the voltage there, do you know what it should be, is there a resitance value associated w the TPS, can the TPS be dismantled and cleaned, is the wiring and connections associated w the TPS in good condition and free from corrosion and splices?

 

The TPS is a known failure point on these cars, but it does NOT control idle speed. Fix the choke FIRST, and start that by visually looking at what the choke plate is doing at cold start and as the engine warms up. There are a lot of ways that one problem can trigger a misleading code in this prehistoric ECU. Please, PLEASE resist the temptation to randomly replace parts. You'll spend a lot of time an money making things worse, potentially.