My Corvette is a '79 L-48 with the TH-350 trans. It has the original Q-Jet carb that was rebuilt last winter.

Sounds like the accelerator pump is takin a doo-doo, or....you may have a vacuum leak.
The accelerator pump may also just need to be adjusted a little.

Take a look at Ken's carb article for a really good course on Quadrapuke carb building/adjusting. Click on the link, then "Ken's Projects"(on the left side of the page), then "Quadrajet"(top of page)....

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Joel Adams
C3VR Lifetime Member #56    
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"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"

Good info there!

I may have a few questions but I'll wait til the hood is up tomorrow.

Thanks.

That is all good advice.  You might want to check the ignition tune-up first, so you know you are starting from a solid base.  Just look at the wires, cap and rotor, and check the timing, since you have HEI.

Larry

Well, KDADDY792008-09-30 11:36:40

"Bad, stale gas from sitting?"

It does, but that is fairly common and not necessary a problem.  Depends on how bad it is.   And yes, old stale gas can also cause the problem.  Check the basic ignition system and vacuum leaks, then perhaps put a good carb cleaner like Justice Brothers or Techron and run it a bit more.  Might cure the problem without any headache.  Other wise check the accellerator pump and adjustments.  Dont overlook the EGR valve.  If it is poening too soon, it can cause the same problem.  Opening too soon is cured by replacing the valve.  IF you disconnect and plug the vacuum line to the EGR and the problem goes away, that's your problem.

Kyster,

Before you change parts...try to adjust the idle mix screws at the base of the carb, you may find that the carb is drooling a bit, check your plugs and see if they are black, white, or brownish. Setting the idle mix can be tricky, turning the screws clockwise will take your plugs from black to brown then white...you want the plus to be brown...if they are white then it is to lean you will need to turn the screws counter clockwise...a little each time and make sure that both screws are set about the same turns. For more info...you should first start with turning the screws inward until they lightly bottom out. When you are doing this make sure that you count the amount that you turn each screw so that you can return them to their orginal spot. This will let you know if they where set the same before you start. The base set of the carb orginally is three turns out...you can start your fine tuning from there. Each time you turn the screws a little you can take it out for a run and then check the plugs again for colour. If you have a vacumm guage you can T hook this up to the vacumm port on the back of the intake manifold, while adjusting one screw at a time reach the highest vacumm reading, but I would still check the plugs for colour...you don't want the plugs to be white...this can cause possible cause damage to the motor down the road.

John,

Carb tuning takes time but well worth it. Don't forget to make sure that the choke is coming off.

I think I found It! Really! I really think I found the problem once and for all!!!

Not the first time I have seen that with an aftermarket air cleaner.   Glad you found it.

So Kevin, should I bring my air cleaner with me to the show?

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Lifetime Member #116
Dave's '82

   

Bring it on, Dave!

I had to put a 1/2" spacer (Mr Gasket) under my aftermarket breather, did earlier realize you had a different breather, if you want to use the aftermarket one this spacer will work for you and it cheap.

John,

Just for tech info....It allows for about 3/4" clearance with the GM bow tie on top, I haven't had any problems with the ones I have installed...yet,  Dave's will be better

I have to admit, I have an aftermarket air cleaner which created the same problem.  I used my  body hammer and created a dimple that allows the clearance for the pump linkage.

I have to admit, I thought about hittin' my aftermarket air cleaner with a hammer, too. I think I was after different resluts at the time, though.

Well, the new GM Performance air cleaner from DaveM did the trick. No more problems!

That's good news, glad it worked for you.

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Lifetime Member #116
Dave's '82

   

Glad it worked.