Throttle/Carb issue (Phantom accel)

[SupremeKing84]

Hey guys whats going on, so ive experienced an issue. My throttle seems to be partially stuck, if the car is in park you can hear the engine sound like someone is holding onto the gas, not insanely high but high enough, and if i let go of the brake when driving the car literally begins to accelerate by itself without me having to touch the gas, checked the throttle linkage itself and it opens and returns back like its supposed to, checked down by the pedal and its not bound or tangled, floor mat isnt pushing up on it either.. When driving i can stop and all fine, just have to stay on the brake or the car will go forward. I sprayed carb cleaner all over the carb and down the throat and there wasnt any improvement. Any ideas as to what could be causing this? Thanks in advance guys

84 Cutlass Supreme Brougham Coupe 3.8 2BBL Rochester

 

[pontiacgp]

sounds like the fast idle is sticking

 

[SupremeKing84]

sounds like the fast idle is sticking

Where is that good sir?. i have no idea about carbs lol my Third gen fbody was tbi

 

[truracer20]

Does your brake pedal feel any different when this happens?
Does the engine idle and run smooth otherwise?
Also do you have an idle speed control solenoid in front of the throttle linkage?
If so try unplugging it and see if the problem goes away(this may turn on the CES light), but this really shouldn't be the problem it's only energized with AC on.
Check for vacuum leaks. Carb cleaner sprayed on lines, carb base, vacuum fittings etc will work for this. You want to listen for subtle changes in engine speed/sound.

I'm starting to think I remember the 2bbl not having fast idle adjustments...

 

[SupremeKing84]

Does your brake pedal feel any different when this happens?
Does the engine idle and run smooth otherwise?
Also do you have an idle speed control solenoid in front of the throttle linkage?
If so try unplugging it and see if the problem goes away(this may turn on the CES light), but this really shouldn't be the problem it's only energized with AC on.
Check for vacuum leaks. Carb cleaner sprayed on lines, carb base, vacuum fittings etc will work for this. You want to listen for subtle changes in engine speed/sound.

I have an Idle air motor, and it runs fine, doesnt stumble or anything like that, just feels like the throttle its slighty stuck open, always... i'll spray it down again tonight and see what happens.

 

[truracer20]

I'm pretty certain the computer control cars don't have an adjustment. Are there any numbers stamped on the carb?

 

[SupremeKing84]

I'll look and see later tonight or tomrrow morning, i know its a 2 barrell rochester, Automatic/Electronic choke, OBD 1

 

[565bbchevy]

It sounds like a vacuum leak possibly caused by a cracked rubber hose.

 

[SupremeKing84]

It sounds like a vacuum leak possibly caused by a cracked rubber hose.

i'll check

 

[Clone TIE Pilot]

I'm pretty certain the computer control cars don't have an adjustment. Are there any numbers stamped on the carb?

The e4me carbs have lots of adjustments. There are three idle speed adjustments, idle mixture needles, and idle air bleed screw adjustments .

It sounds like the OP is having a surging problem. Surging is usually caused by a lean fuel mixture. Chances are you throttle shaft bores are worn and leaking vacuum. Has your car's base plate ever been rebushed?