NoTransistors

First of all, the mysterious intermittent exhaust noise hasn't appeared in a whole week. Hard to have an engine noise with the intake manifold off.
I am renewing the intake gaskets. One side began peeing a gallon per week.
Because the carb is off, it got a very generous shower of carb cleaner. Clear solvent in...Brown solvent out of the thing when I sprayed into certain areas of the bottom. I thought that the fuel is a cleaner.
Back to the point. I have owned this car for several years. In that time, it had accelerated by itself five times. Imagine going through the Holland tunnel at 100 m.p.h.; or down Coney Island Avenue at 85 m.p.h.
The parts guy at the local G.M. dealership tells me that this is a real problem that the manufacturer has never admitted to.
When this happens, the pedal seems to go down to the metal.
It has not happened in a year. *** knows what will happen with a clean carb, and posibly more intake vacuum.
Any thoughts?

Apeiron

The parts guy at the local G.M. dealership is an idiot.

87Formula4bbl

There is no 'real problem' that needs admitted to. Apeiron is right, the guy behind the desk sounds like he doesn't know what he's talking about, or just feeding you a line. How is your throttle sticking wide open, did you figure it out? Most likely your linkage was hanging up on something, or your springs are very weak, or both, who knows. Throttle blades normally don't just stick open by themselves for no reason with a spring(s) pulling them shut.

I had my throttle stick once on an onramp, scared the crap outta me until I finally (I say finally as if it was a long time, but in reality was probably more like 4-5 seconds) thought to just switch the key off. I rolled it over to the side and popped the hood. Low and behold, a piece of vacuum tubing I had been messing with had fallen into the secondaries and kept the throttle blades from closing. There was no air cleaner on it because I had been messing and testing. But anyhow, kind of no point to that. I'm just saying, it's gotta be something that caused it, but not an injerent problem with it that I know of.

NoTransistors

Blindly calling someone an idiot only makes YOU look like one.
I thought that Canadians were better than that.

87Formula4bbl

All that, and not to say that your carb doesn't need rebuilt or cleaned though...

Apeiron

There have been millions of quadrajet equipped cars made since 1965. Do you think GM could keep a serious flaw a secret from the NHTSA for that long in the Litigious States of America?

NoTransistors

My U.P.S. delivery person had a 350 Camaro, with this same problem. Same carb and computer. The cable does not get stuck.
The carb does go to a frightening w.o.t., and the aftermarket springs, which are very tight, do nothing for the problem.
The other 364 days of the year, this carb provides superb , Roll Royce-like idle, and easy hot and cold starts.
The temperature valve for the cannister purge valve has been broken for some time, and I wonder if this can have anything or nothing to do with the problem...Nah, doubt it.

87Formula4bbl

You may have an ooompah-loompah under your hood working the linkage from time to time....

haha, jk

NoTransistors

How many people got killed in the Ford 4x4s, before something was done about the tires? The U.S. was one of the LAST countries to file suit against Ford.
How mand died in the V.W. Bug, before the seat tracks were finally redesigned for the Rabbit/Golf?
There are countless more examples. Money comes before lives in this country.

87Formula4bbl

Have you thought about the cruise-control? Maybe it's giving you problems, somehow it got stuck on 'resume'?

NoTransistors

Very bright idea, but after the C.C. trashed the speedo cable, I eliminated it, and got a one-piece cable. This was many years ago.

mnegovan

The only thing I could possibly blame this on is a bad Throttle Position Sensor in the carb itself sending a bad voltage to the computer. What you can do is follow the service manual to check the TPS voltage. When you work the throttle you will notice the voltage increase. It should change smotthly as you move the throttle. If the TPS is shorting internally that may expain it. But I am not sure about this. This is the only thing that the computer could mess up on. The TPS sends the signal to the computer, the computer adjusts its pulses to the M/C solenoid based upon the throttle position. Or else you are accidently hitting the NOX button

Apeiron

A faulty TPS wouldn't explain the change in speed at all. The MCS could be in full rich or full lean all the time and you'd hardly notice. There has to be air getting in, either through a vacuum leak or the throttle blades or something.

TMX

Eliminated what, the two-piece speedo cable, or the entire cruise control system? If the cc servo is still there and hooked up, that's where i'd start looking.

If it's not the cruise, then there's absolutely nothing else that could cause what you're describing. Nothing.

-B

mnegovan

Thanks for clearing up the TPS and M/C operation. I really need a good theory of operation manual for the Rochester carb.

If the cc is not hooked up then I would put on a stronger spring for the throttle linkage.

NoTransistors

The c.c. is completely gone. Only the turn-signal stalk gives you any notion that this car had c.c.. I am using the c.c. on/off switch as a switch for the converter lock-up. Gives nice results.
The carb return springs are aftermarket, and really tight.
I know that you cannot believe it, but the carb acts just like those 1st electronic Audis. Sudden, unexplained acceleration., once every few years. Could it be the alignment of the moon with Jupiter, or something?
B.T.W., I just replaced the intake manifold gasket set, and had no parts left over. The timing marks are wierd, though, and it was so great when the fan blade caught the timing light wires, and the a.c. belt then swallowed up the alligator clips. Lucky that it is only a beautiful Sunlight, rather than a cheapo unit. Ha Ha
P.S. I have 23" Hg at 600 r.p.m. with timing at factory spec.
Can get up to 26"Hg if tuning by vacuum guage, rather than a timing light.
Nice for an old car.