Gas squirt?
11-15-2017, 11:13 AM
#1
Pro
Thread Starter
Gas squirt?
Stock '77 Q-jet....just rebuilt ,epoxied plugs.
With engine cold and not running when looking down in the primaries you should see a squirt of gas when cracking the throttle(choke vane blocked open)...correct?
Until engine warms I have to hold idle very high(around 2k)to keep car running...even then it wants to surge down at times and I have to lightly pump(feather) gas peddle to bring rpm's back up and keep it from dying.
Once warm there is big hesitation when quickly cracking throttle open wide...idles at around 1,200....if engine dies I have to dump a little fuel in carb to get it to restart.
Am I describing classic accelerator pump failure?
Thank you for any help!
With engine cold and not running when looking down in the primaries you should see a squirt of gas when cracking the throttle(choke vane blocked open)...correct?
Until engine warms I have to hold idle very high(around 2k)to keep car running...even then it wants to surge down at times and I have to lightly pump(feather) gas peddle to bring rpm's back up and keep it from dying.
Once warm there is big hesitation when quickly cracking throttle open wide...idles at around 1,200....if engine dies I have to dump a little fuel in carb to get it to restart.
Am I describing classic accelerator pump failure?
Thank you for any help!
11-15-2017, 11:40 AM
#2
Le Mans Master
That is correct- for the front (primary) side of the carb. Good shot of gas when you open the throttle.
The warm up thing may be the choke is not functioning properly- there are a few things in that choke system- the vane across the top of the primaries, the choke thermostat, choke pull off, aka. Vacuum Break, and the fast idle cam. Any one of those, or a combination, could be your cold idle/start problem.
IT does sound like your accelerator pump is weak/dying/dead.
The warm up thing may be the choke is not functioning properly- there are a few things in that choke system- the vane across the top of the primaries, the choke thermostat, choke pull off, aka. Vacuum Break, and the fast idle cam. Any one of those, or a combination, could be your cold idle/start problem.
IT does sound like your accelerator pump is weak/dying/dead.
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Chicago Bob (11-15-2017)
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Chicago Bob (11-15-2017)
11-15-2017, 01:55 PM
#4
Pro
You could be describing a very rich or very lean condition. Both will create a bog or hesitation off idle. You could pull a plug and see if they are sooted up. You may have the accelerator pump on the wrong notch (easily done on rebuild). I agree, triple check float levels and condition.
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Chicago Bob (11-15-2017)
11-15-2017, 03:51 PM
#5
Had a 1976 L-82, 4-sp
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I mentioned the float level because when I bought my vette used, it had a bog on hard acceleration. I adjusted the float to the proper level and bog was gone.
11-16-2017, 02:39 PM
#6
Pro
Thread Starter
Thanks everyone for the help!
I have an update....
When I removed the carb to rebuild I wrenched the original hard fuel line pretty bad...soooo, on the reinstall had to splice in a 2in. piece of rubber hose right at carb inlet....one of the hose clamps was not tight
not enough that fuel was leaking but I guess enough to allow air because once I tightened it down the engine runs like a differ car. 
I think I learned a lesson on this one...
I have an update....
When I removed the carb to rebuild I wrenched the original hard fuel line pretty bad...soooo, on the reinstall had to splice in a 2in. piece of rubber hose right at carb inlet....one of the hose clamps was not tight
not enough that fuel was leaking but I guess enough to allow air because once I tightened it down the engine runs like a differ car. I think I learned a lesson on this one...