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73-87 Chevy _ GMC Trucks => Performance => Topic started by: pedigo78 on September 11, 2011, 06:45:09 pm

Title: Engine not getting fuel or to much air
Post by: pedigo78 on September 11, 2011, 06:45:09 pm
So I notice that when I am driving less than 15mph and put the pedal to the floor then engine goes completley quite and dies. i think the carb is not sending enough fuel when the butterflies open up. I have had problems with my carb in the past but thought i had it fixed. it only does this at low speed, and its the only problem i am having with it. Maybe it just needs to be adjusted, or is the jets or squirts to big? I am not sure.
Title: Re: Engine not getting fuel or to much air
Post by: 1980c10 on September 12, 2011, 01:24:06 am
Start by checking the accelator pump.
What kind of carb?
Title: Re: Engine not getting fuel or to much air
Post by: jaredts on September 12, 2011, 04:19:01 am
What kind of carb.?  Does it run rough/die at light throttle or is the problem only momentary when you first give it a little gas?
Title: Re: Engine not getting fuel or to much air
Post by: pedigo78 on September 12, 2011, 07:36:30 am
its a holley 750, and no it idles good and smooth, it will only die if i floor it, but if i am driving normally it is just fine.
Title: Re: Engine not getting fuel or to much air
Post by: 78 Chevyrado on September 12, 2011, 10:54:10 am
kinda sounds like the secondaries are opening up too fast and too soon.  mine would act like that when I was setting up my secondaries.

I dont know about a holley, but on my edelbrock, the secondary butterflies do open all the way when you mash it to the floor, BUT the edelbrock also had an upper set of "butterflies" (cant think of a better word now) above the seconadries and they only open as far as is required.  in other words they open only if the engine can use the extra air.   

otherwise, I'm thinking maybe to adjust the accelerator pump. 

if the secondaries are out of adjustment, opening too soon, it will get really lean and die
if the accelerator pump is off it can make it lean or rich.
Title: Re: Engine not getting fuel or to much air
Post by: Irish_Alley on September 13, 2011, 12:43:58 am
a 750 on what engine?
Title: Re: Engine not getting fuel or to much air
Post by: pedigo78 on September 13, 2011, 12:14:36 pm
454 bored 30