Carb jammed
Thread Starter
Instructor
Joined: Mar 2010
Posts: 219
Likes: 0
From: Texas
Carb jammed
I got my carburetor rebuilt months ago. The shop guy told me when i got it back " on cold your she'll rev up high and give it a second, hit the gas ans she'll calm down to 10 so you can get going." This has worked fine.
Now the car will lock/stick while im driving. Poped the hood and noticed the accelerator cable is not as firm as i remember it to be but i rarely prod at it to gauge it. Im trying to see what my options are getting it fixed. New carb? Tighten cable, if so how?
Thanks fellas in advanced
Now the car will lock/stick while im driving. Poped the hood and noticed the accelerator cable is not as firm as i remember it to be but i rarely prod at it to gauge it. Im trying to see what my options are getting it fixed. New carb? Tighten cable, if so how?
Thanks fellas in advanced
Race Director
Joined: Jan 2000
Posts: 12,399
Likes: 247
From: San Jose CA
How does it "lock/stick"?
Did they rebush the throttle? Sometimes the bushings will be a bit too tight and the throttle shaft needs to be reamed. A good test is to disconnect the throttle cable and throttle return springs (with the engine off) and manually open the primary throttle blades. Once you let go, the accelerator pump spring should be able to force the throttle back to the idle stop. If this test fails, you'll need to take the throttle body off and disassemble it, and lap the throttle bushings until you get a smooth rotation of the throttle shaft. A barrel lap is an excellent tool to use for this. You really need to do it a couple times to get a feel for it though.
Assuming that's not the case, the choke may be set up too tight, to the point where it's just barely disengaging. I'd also consider throttle return springs being too weak. If the cable was weak, you'd actually get LESS throttle, not more.
If you do fail the accelerator pump test, me, Lars, Cliff, Henry and numerous others can rebush/service the throttle body for you.
Did they rebush the throttle? Sometimes the bushings will be a bit too tight and the throttle shaft needs to be reamed. A good test is to disconnect the throttle cable and throttle return springs (with the engine off) and manually open the primary throttle blades. Once you let go, the accelerator pump spring should be able to force the throttle back to the idle stop. If this test fails, you'll need to take the throttle body off and disassemble it, and lap the throttle bushings until you get a smooth rotation of the throttle shaft. A barrel lap is an excellent tool to use for this. You really need to do it a couple times to get a feel for it though.
Assuming that's not the case, the choke may be set up too tight, to the point where it's just barely disengaging. I'd also consider throttle return springs being too weak. If the cable was weak, you'd actually get LESS throttle, not more.
If you do fail the accelerator pump test, me, Lars, Cliff, Henry and numerous others can rebush/service the throttle body for you.
Thread Starter
Instructor
Joined: Mar 2010
Posts: 219
Likes: 0
From: Texas
How does it "lock/stick"?
Did they rebush the throttle? Sometimes the bushings will be a bit too tight and the throttle shaft needs to be reamed. A good test is to disconnect the throttle cable and throttle return springs (with the engine off) and manually open the primary throttle blades. Once you let go, the accelerator pump spring should be able to force the throttle back to the idle stop. If this test fails, you'll need to take the throttle body off and disassemble it, and lap the throttle bushings until you get a smooth rotation of the throttle shaft. A barrel lap is an excellent tool to use for this. You really need to do it a couple times to get a feel for it though.
Assuming that's not the case, the choke may be set up too tight, to the point where it's just barely disengaging. I'd also consider throttle return springs being too weak. If the cable was weak, you'd actually get LESS throttle, not more.
If you do fail the accelerator pump test, me, Lars, Cliff, Henry and numerous others can rebush/service the throttle body for you.
Did they rebush the throttle? Sometimes the bushings will be a bit too tight and the throttle shaft needs to be reamed. A good test is to disconnect the throttle cable and throttle return springs (with the engine off) and manually open the primary throttle blades. Once you let go, the accelerator pump spring should be able to force the throttle back to the idle stop. If this test fails, you'll need to take the throttle body off and disassemble it, and lap the throttle bushings until you get a smooth rotation of the throttle shaft. A barrel lap is an excellent tool to use for this. You really need to do it a couple times to get a feel for it though.
Assuming that's not the case, the choke may be set up too tight, to the point where it's just barely disengaging. I'd also consider throttle return springs being too weak. If the cable was weak, you'd actually get LESS throttle, not more.
If you do fail the accelerator pump test, me, Lars, Cliff, Henry and numerous others can rebush/service the throttle body for you.
What i mean as in lock/stick is that when im driving the car will accelerate and stay engage to pick up speed until i pump the gas again and then it disengages and comes back to where im controling the speed
Race Director
Joined: Jan 2000
Posts: 12,399
Likes: 247
From: San Jose CA
That sounds _more like_ the choke, but could also be the linkage binding somewhere else. Do you know if the throttle body was rebushed or disassembled and reassembled during the rebuild process?
Tech Contributor
Joined: Aug 1999
Posts: 14,356
Likes: 6,328
From: At my Bar drinking and wrenching in Lafayette Colorado
Why don't you take it back to the guy who screwed it up and tell him to fix it...? The engine should not "rev high" on cold start - it should idle normally at about 1150 rpm cold. You should not have to "hit the gas" to get the fast idle to correct itself - the fast idle should operate smoothly and transition-less with no weird throttle input. If the throttle is jamming, and it wasn't before, that's a serious safety issue, and the guy should correct the problem. Immediately.
Lars
Lars
