1983 F150 high/sticking idle and low power (maybe?)
 

Hi i have a 1983 F150 straight 6 and i've been driving it for about a year now and it's always had a problem where it will idle really high, or when i shift gears right when i press the clutch down it sounds like the rpms shoot up to like 2500 or something.

sometimes at a red light i have to keep tapping the gas to try and get the RPMs to go back down, sometimes this works and it idles at a normal pace but it will still sound like it's shooting up to 3000rpm when i press the clutch.

sometimes though if my truck has been sitting for a while and i start it up, it will drive perfectly and sound great and there will be no surging but this will only last for a few miles.

another problem i've been having is that i'm not sure if i should be getting more power out of this truck, or if this is the best it does. I can go about 55mph max before it sounds like i'm shooting up to 4000rpms. i start off in second gear and it gets me to about 10mph and then i switch to 3rd until 20 and then 4th from 20-55

oh one last thing when my car is running well (like in the scenario described in the paragraph above the last one), it will seem like my car is getting more power, like i can get to 15 or 18 mph with second gear and it doesn't sound like it's stressing the engine.

i'm not really sure where to start or if you guys need any more information to try and help me.

thanks,

jack

Do you know what the choke is on the carb? It sounds like it may have a problem, possibly flopping around giving you a intermittent high idle and choking the engine off.

Is the choke the thing that allows more air into the carb for cold starts?

Is.there a diagram.or an.explanation of the part and.how it should be working so I can take a look at it?

The choke is the large metal door right on top of the carb. It blocks(or "chokes") the air off so the engine runs richer when it's cold.

It's controlled by the large round black piece of the side of the carb. It also has linkage that holds the throttle open some to help the engine run when it's cold.

How does this engine run on first start up in the morning? That's when the choke is supposed to do it's job. You could mark where the black piece is, then turn it back till the choke door is open, and then see if the other problem goes away. But it may make it hard to start in the morning.

the engine usually runs perfect in the morning and is not hard to start at all.

it's just after a few minutes of driving i start hearing the surges in the idle when i shift and the high idle at neutral.

also another thing is that my oil pressure indicator says there is no oil pressure but i've been driving it for a year now and it's been find so i'm assuming that it's a defect in the sensor, but i may be wrong.

i'll go see if i can mess around with the black piece you were mentioning.

The "black piece" is held in place by three screws, each 120 degrees apart. Look at the top of this housing and you will see index marks. Most times, on one end it will say "lean" and on the opposite end it will say "rich". With the air filter removed, so you can look down the carburetor, and if the engine is cold [and NOT running], slowly press the pedal to the floor and slowly release. This should set the choke. Then look down the carburetor. The choke plate should be closed or open at the most approximately 3/16".

If it is too open or too closed, adjust the black plastic piece perhaps one mark at a time, noting where you started. It is easy to mark the metal housing using a small screwdriver. That way, you can go back to the original setting if need be.

Adjusting a choke is easy, but takes time. Be sure to retighten the 3 screws. Make the adjustment and drive and make another adjustment the next day, if needed. It is not at all uncommon to need to tweak the choke settings with the change of the seasons.

I remembered this being discussed, previously. Perhaps this link will shed some light. Good luck! :)

https://www.ford-trucks.com/forums/1...ent-101-a.html