why does my truck die when i punch it???

[jasonroman]

any time i stand on gas from a dead stop, the truck falls on its face. and shuts off.
other wise truck runs great. no misses or hesitation anymore.
timing is on i believe....well timing light has me in the 30s i think. but if i put it at 12 and go from there, the truck runs like dog doo. so i have it where the truck runs good and has no misses or hesitaion like i had before.

i was wondering if maybe the carb can be flooding out or something??
carbs a qjet.
i was wondering if theres a screw i can turn and direction i should turn to see if i can get truck to go when i get on it. as opposed to it shutting off.
thanks for any help or advice.

[nbpro]

What year is the truck the engine size this may help in getting a answer

[Adams74Chevy]

without more info I'd guess the carb could need rebuilt. My carb stumbles right before the secondaries kick in, but starts and runs great otherwise.

[PRattenbury]

Why do you floor it from a standing stop anyway? Like spending money on tires and traffic tickets? That said, I'd guess accelerator pump in the carb.

[charx2]

Originally Posted by PRattenbury

Why do you floor it from a standing stop anyway?

No offense but I can't believe you have to ask that question. I love being pinned to my seat while smoking them out. Granted I don't do it on busy streets or anything, but it's still fun to me. My guess would be the carb, maybe it's time for a rebuild? I just rebuilt my edel 1405 because it was constantly flooding. It was actually quit easy as long as you have patience and a clean area to work. The instructions had me intimidated but it was really easy.
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[nbpro]

Edelbrock and a Qjet are different animals when it comes to rebuilding

[knightowl73]

Originally Posted by nbpro

Edelbrock and a Qjet are different animals when it comes to rebuilding

very true, id never try to rebuild a quadrajet without a q-jet guru's help. ill tackle any edelbrock carb now with confidence. thought it would be hard so waited for 2 mos for a buddy to help me, who kept insisting i could do it myself. after all that waiting and finally him showing up to do it,, i was like " damn, thats all?

also had went thru 4 q-jets before rebuilding the Eddy one, all ran different, apparently one was fine for about 2 weeks before it let out on me, and the performance was way better than the eddy on that particular q-jet, so i know they work well when done right....the Eddy is just easier and foolproof pretty much for me, dependable too.

i buy the Eddys whenever i can for less than 75 bucks on CL then rebuild them so i have spares for other projects that may come along, alot cheaper than buying any carb new or rebuilt, and i can do it myself.

[jasonroman]

ok. truck is 85 gmc sierra classic
motor is gm 350. replaced by po.
i think originally was a 5.0. now told its a 5.7 but un sure

y would i stand on gas....not to spend gas. but every now and then a guy wants to go. not that im a 17 yr old with a hard on to spin wheels.
just that i remember my 82 with 350, i would stand on gas, and lay a patch the size of a football field.
this one, i stand on gas and it shuts off. no sputter or hick up. just shuts off.

truck sat for a while before i picked it up. and since i have it, i have not rebuilt carb. i dont think i would try it. ive read alot that a good tuned q jet beats ebrocks and holley carbs all day....key being properly tuned and built.
got a couple quotes near and over 200 for rebuilding carb.
for that i figured i could just buy a new ebrock and go.
but right now i dont have the money to buy carbs or rebuild. moneys tight and holidays are coming. 2 kids, and one that happens to be born on xmas....

so i was hoping maybe i can turn a screw here or there and help my issue a bit.
if not, hopefully after holdidays, ill look to change intake, carb and possibly have a cam thrown in, well those are what id like to do....who knows.

thanks for replies thus far.

[charx2]

Yeah, I hear ya on the money issue, that's why I do almost everything I do myself. I am now a self taught shade tree mechanic who knows very little. Pretty much just enough to make me do things twice over, the wrong way, then the right way to fix lol.
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[82swampthing]

q-jets are very easy to work on.everybody makes them out to be worse than they really are because they don't understand how they work.just pick up a rebuild kit and a bucket of carb cleaner and rip that thing apart.Thats how you learn with hands on expirence.there not any harder to work on than a holley or edelbrock.an if you don't want to try taking yours apart first go to the junk yard or swap meet and pick up cheap one and tear it down and see how it goes together.

[irishman999]

Originally Posted by 82swampthing

q-jets are very easy to work on.everybody makes them out to be worse than they really are because they don't understand how they work.just pick up a rebuild kit and a bucket of carb cleaner and rip that thing apart.Thats how you learn with hands on expirence.there not any harder to work on than a holley or edelbrock.an if you don't want to try taking yours apart first go to the junk yard or swap meet and pick up cheap one and tear it down and see how it goes together.

Swamp thing is completely right. Your about 10 hex head screws from finding out how simple it is. I found in mine... Metering rods connected to a plunger with a little wire spring, A single float with a plunger connected to it by a little tiny wire and the power pump assembly. I put my carb in a bucket of gasoline and let it soak a while, spent about 25 bucks on a JP Sorsen kit from autozone and sat down with beer in hand and within a couple hours had a great efficient carb with great power on tap. You can even turn down the metering rods about 3/4 of a turn and get great mileage.

[nbpro]

I ended up learning how to make QJets run becase it was the only 4bbl carb I could lay my hands on as a 16 year old (52 now)for $15 each at the junkyard. What started as a consequence of necessity turned into an appreciation of just how flexible these fine carbs are. NONE of them are good in factory-stock tune. But once you know what it takes to make them run you can get some very good results out of them. The Q-jet has small primaries with HUGE secondaries.
So, you will get better gas mileage until you hammer it.i am on a budget and the Edelbrock was free thats why i have the Edelbrock But for a novice Edelbrock is much easier when it comes to rebuilding My $.02