During regular operation carb runs fine. If I'm at a roll and stab the throttle, it sticks open at 2200rpms: driving with 2 feet ones the brake while I stab the pedal 5-6 X before it unsticks. Tried to recreate while under hood in park no dice. Changed return spring w/ a little stiffer one no good. What else can cause the gas pedal to stick on medium to full throttle movement? Problem just began this week haven't disturbed anything there
I've had the carpet in the car hang up the gas pedal or cable and I've had cotter pins installed in such a way they were able to hook parts of the carb if they rotated at full throttle. A previous owner of my Firebird thought it was a good idea to use a nail to hold the gas pedal on.... It also hooks carpet quite nicely uzzled: That one took me a while.
How is the throttle shaft-to-throttle body fit? Common wear-point, and if the throttle shaft is kicked out of alignment due to worn throttle body, the plates won't close properly. Having the throttle springs hooked rearward of the throttle linkage makes this worse, even though that's the OEM location sometimes. Any machine-shop can install bushings to repair this condition, and guys like Cliff Ruggles sell a do-it-yourself drill bit and bushing kit.
I have also seen the angle of spring be a problem. On my car, I had to raise the spring connection point toward front of intake.
Only when I lay into throttle more than 50%;can't recreate when under hood in park , takes 4-5 good jabs on throttle to unstick or will stick at 2000-2300 in drive. Going to post a few photos if anybody sees anything hinky in a minute when I get home.
Check that your throttle plates arent sticking on manifold happened to me when my carb got a little loose and slid back would be like cruise control it held at same rpm basically 1/4 throttle or so I have a TA intake though and it does not do it now that I added a spacer
Three things- 1. In the one picture, the throttle lever looks bent. This may be a spherical aberration artifact of the camera, though. If it is bent down, bend it up so that the spring has a better angle for pulling the throttle shut. 2. I don't see a whole lot of light between the coils of the return spring, so it may not be pulling all that strongly to close the throttle. You might consider getting a different spring that has more spacing (=more return force). 3. Spray some carb cleaner at the throttle shaft on both sides of the primary throttle plate. If you get a big change in engine speed, the throttle plate is worn, as has been mentioned. You can fix that yourself, if you are interested, or send it out for repair. Given the cost of the tools and parts in the kit (and having few carburetors to repair), I just send mine in for repair. You could do the same, unless you are in a hurry for the repair. NB- in the past, I worked as a mechanic for a living, and I've put NEW replacement carburetors on and had the same problem out of the box.
You mentioned its getting chilly: Make sure your choke is set proper, and not trying to engage the high idle cam.
Figured it out after checking out everything suggested but what was causing it was " off the beaten path" to put it mildly . I installed an oil pressure gauge last month using copper line. For added peace of mind I encased it in rubber tubing. Where it entered through firewall (pict) I routed too close to the gas pedal when at more than 50% throttle, the line bound up the pedal . A little rerouting & kicking myself problem SOLVED !
I agree with Randall- copper work hardens if it gets bent a lot. It doesn't take much, and once it gets hard, it can crack easily. I use Nylon oil pressure lines for this reason, and check them periodically anyway, since if the Nylon tube gets next to too high a heat, it's gone even quicker.
I've gone to full electric gauges now. As a teenager and early-20's I never was able to get the copper lines to fully seal and inevitably there was a coating on the gauge and eventual drip. It'd take months to get to that point, but still. I refused to use nylon after seeing the result of a line break in my friend's El Camino. Since about 2008 I've put electric oil pressure gauges in all four of my old cars.
That's the way I'm leaning now for gauges, including temperature, but I really like the big swing of the mechanical gauges; easier to read at speed. I'll have to look, maybe the designs have changed.
Anything worth more than a pinch of poo always costs more money. I'll have to look around, and price the parts I'm reselling to cover the cost, so that the wife doesn't hate my Buick habit too much.
