accelerator pump.

[IOWNATRUCK]

alright, so here we go, in park, my truck idles perfect, starts good, responds to throttle perfectly, no problems. now in drive, i can accelerate slowly perfect, sometimes i can mash the throttle down and accelerate perfectly, but sometimes if i mash the throttle down, theres a pop from the engine compartment, the engine rpm slows, and then raises and accelerates fine, ive talked to people and some say accelerator pump. well my carb is new, and it takes throttle perfect in park. now me, i was leaning towards something simple, like maybe bad gas, low gas (cause when i was driving it, it had probably 1-2 gallons of gas in it total, and the tank hadnt been cleaned so im sure there was 30 yr old gas and soot in there as well) are those possible causes of this problem? when i take the air filter off and give some gas, i see gas coming out of all 4 jets. sometimes it does it, sometimes it accelerates perfect, which made me think its not the pump. no vacuum leaks, or anything of that sort. its an edelbrock performer series carb. it doesnt happen all the time, and im leaning toward old dirty low gas. any opinions are appreciated man its bugging me ha,
Thanks.

[ttcunn]

My first reaction is to say.....go put in a few gallons of some really good fuel and an additive like Chevron's Techroline. I know that stuff works. Then see how it performs, I think you are on the right track.

[irishman999]

I would double check the timing, maybe advance it a little bit.

[INSIDIOUS '86]

It takes time for the secondary air door to flap open on an edelbrock carb. That's why it seems like it hesitates a little when you mash it. The door opens suddenly and then you rocket off. Try this simple experiment try mashing it at low rpm and then try mashing it at as high rpm as you can get it without opening the secondary throttle plates or over rev the engine. The higher rpm will probly have very little hesitation due to the engine taking so much air at once vs low rpm and low air demand
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[Your41Plague12]

Sounds like a problem I recently had with mine. It ran perfect in park, but with a load on it (in gear) it seemed to hesitate and sputter. I played with the timing and put a new cap, rotor, and coil in it and it works like a dream now. I second the notion of making sure your fuel is all right first before dumping money into it.

[Corts60]

The carb is popping when you mash on it because of a lean condition. I think you may have a timing issue rather than a carb issue. As stated above, maybe advance your timing a little bit, but first I would ensure that your vacuum advance is working properly. If it is connected to a ported vacuum source right now, try hooking it to a manifold vacuum source then drive it and see what you think.

[Axle]

Pull the airhorn off the carb and check for dirt/crud in the fuel bowl. If there is, clean it out, along with the accelerator pump passage (screw in the bottom of that well-theres also a check ball under it that you'll need to remove. Blast it with carb cleaner (don't lean over the carb when you do that)).
IF you find black specs in the fuel bowl, your carbon canistor guts are getting sucked into the carb. Blow out the hoses with air, and either replace or block off the carbon canister.

Alex.

[IOWNATRUCK]

ok thanks to all, now to respond, all my plug wires, distributor cap, coil wires, all those are new, because i replaced all of those when i dropped the new engine and carb in, ive dropped my gas tank and cleaned it and am going to reinstall it in a few days, im hoping that helps, but in regards to the people thinking its timing, what are some excessively retarded timing symptoms? idle is good, revs keep up, im thinking the timing is ok, and to clarify, i wouldnt consider it hesitation, its more like i mash it down, theres a pop, and suddenly im going extremely fast, its not as if the engine isnt keeping up with the throttle and such. and as for what insidious said, are you saying its not a problem, its just a typical symptom of the edelbrock carb, and that if i mash it down as fast as possible that i should expect reaction like that as it just simply needs time to catch up?
Thanks.

[IOWNATRUCK]

now that ive been researching even more online, more and more websites are saying it could just be low gas or bad or old gas, thanks for all the help, any more responses or opinions are appreciated, for now im thinking and hoping its just low or bad gas, since everything is basically new that could relate to this problem and that you guys are suggesting, im hoping it just needs new clean gas, and alot of it, ha thanks everyone.