Not idling, sputtering

[Observer]

Car starts up fine and runs for a while.
Then it begins to sputter badly and I have to rev the engine for a while, very strong smell of fuel and I am burning gas like crazy.
I can run the car on the highway fine, but once I slow down in traffic it sputters badly and stalls if I don't rev the engine quite high.

Replaced the Large Intake Hose.
Checked all the hose for cracks and potential leakes
Cleaned the Cold start Sensor and tightened the clip.

[narfire]

Not sure but unmetered air getting into the intake? Check with someone manning the throttle and you with a propane bottle on low and wave it about close to the black intake, around the throttle position sensor, brake vacuum line, get the idea? if the car revs up at a point, you have an air leak. Not sure how you checked, if you did it this way, that's great
remember propane sinks so be careful.
Not sure what your skill set is but the AFM has an arm/pin? that rotates( with the plate you see inside) as airflow increases. If you take the black plastic top off very carefully ( can be a pain) you'll notice an arm on the vertical pin. End of that moves along a strip. The very small pins on the end will have made two tracks along this strip and the beginning part of the strip ( idle and low rpm) it can be warn and give you issues at low rpm. If you can, loosen the screws and VERY carefully perhaps bent that fragile arm just a tad so those pins are perhaps 1/2 to 1mm over and into fresh part of the track. Can clear that issue up.
Just a couple of causes...
Plugs?
Fuel lines rot and leak over time as well. Perhaps have a injector line that is compromised?

[lglade]

Narfire has some great suggestions, and here's another one. My 1984 was doing the same thing and it turned out to be a short in the wire to the coolant temperature sensor, although a bad sensor will to the same thing. With the engine idling, grab the wire to the sensor and see if the problem stops.

Here's a video:
https://www.youtube.com/watch?v=4ypYUq5ri_k

[Observer]

Narfire has some great suggestions, and here's another one. My 1984 was doing the same thing and it turned out to be a short in the wire to the coolant temperature sensor, although a bad sensor will to the same thing. With the engine idling, grab the wire to the sensor and see if the problem stops.

Here's a video:
https://www.youtube.com/watch?v=4ypYUq5ri_k

Thank you. I tried as suggested no change. However, if I unplug the coolant temperature sensor with car idling the engine cuts off.

[micbrody]

Have you checked idle screw o-ring? Maybe as car gets to operating temperature, the small expansion of metal is causing too much idle screw air to come through; or maybe maybe just really dirty.
In any event:
Remove idle screw; inspect gasket for cracks; use carb cleaner in hole and on screw; also clean hole with q-tips.
Then reinsert screw. Get car started; once it is going, let it come to operating temp (two radiator fan cycles). Then adjust the idle and throttle stop screw: screw idle screw totally in/closed . Then adjust throttle screw stop to get idle around 850ish rpm. Once there, open up idle screw to get Rpms to 900-950.

I forgot to mention two more things:
Check the throttle position sensor. When throttle plate just barely opens, you should hear a click (there is a way to use ohm meter to check for "continuity click", but off the top of my head I don't remember which of the three terminal to put probes on)

The other thing to check: does your Rpms change at rest when you hit brakes on and off? Maybe a leaky brake booster or hose leading to brake booster. One way to check is to just clamp hose from intake manifold that goes to brake booster; or just remove hose and cover hole with tape(heat resistant) . See if idle improves. (Be careful about driving as you won't have any brake boost to help )

[KevAndAndi]

I had the same problem, which turned out to be caused by an AFM that was not working correctly. I had it rebuilt, and now the car runs great.

[Observer]

Had almost everything check as recommended, including AFM, with no luck at all. The car runs fine on the highway, but once I have to engage the clutch it stalls.

Question: Could it possibly be the clutch that is causing the car to cut out in traffic?

[grrrdot]

Could it be a leaking injector?

Any trouble restarting hot?
If you pull the spark plugs after the car has idled for a bit what color are they?
The color will tell you if it’s rich / lean.

-G

[Observer]

Thanks!

Injectors are fine and all plugs are burning normal.