just Rebuilt rochester q-jet starts good, runs good, won't start after shutoff

[rattlehedchris]

I just finished rebuilding my carburetor. its a rochester  quadrajet 17057213. The car ran perfect, but the carb started leaking gas, so I decided to rebuild it myself for the first time. i finished it. well, it started fine today, real easy. I let the car warm up, tested the rpm range (revved that gto!) and went for a test run to the store down the road. When  I came out and started it to leave, it wouldn't start. Just a steady cranking unsuccessful. It seems gas isn't getting through somewhere in the carb, but the fuel lines up to that point are good. Is there supposed to be gas spraying through the two tubes in the carb that come out under the air horn? I got towed home because the a-holes at the Shell I had just spent money at said they would call my car in to be towed away, but I wasn't gonna leave my gto there! and I towed it to my house with AAA till I can fix this. I reused the old filter and accelerator pump, but replaced all my gaskets, cleaned all my parts really well. What could it be? I have the fuel filter on order right now.

[Cliff Ruggles]

Did you install a Viton needle/seat assembly and new float?  We see a lot of this sort of thing, ethanol is hard on rubber parts.  All of the carburetor internal components should be replaced during a "rebuild", with ethanol resistant parts.  Over the counter kits still contain neoprene and rubber parts, and do not contain the needed parts for a complete/correct rebuild.

Our kits come with dozens of parts not found in over the counter kits, upgraded for ethanol fuels, and improved performance.

We also include the float, and fuel filter w/spring......Cliff

[stope4]

I have a 68 carb on a Camaro doing the same thing. I am getting suggestions that I need a phenolic spacer. I don't think these cars had spacers to start with so I am hesitant that is the solution.

Rattlehedchris - I'll bet if you go out tomorrow and try and start your car it will start. The next time you take it for a drive and it won't start after shutting it down, press the pedal to the metal holding the accelerator to the floor and try and start it. It will probably start up after a few cranks.

With that said, it still isn't working right so Cliff's suggestions are more than likely right on.

Cliff, can you try and explain what is happening when the car will not start after setting for 30 minutes or so after the engine was good and hot? And please explain why flooring it while cranking seems to clear out the excess gas or no gas, whatever is happening?

[stope4]

I have a 68 carb on a Camaro doing the same thing. I am getting suggestions that I need a phenolic spacer. I don't think these cars had spacers to start with so I am hesitant that is the solution.

Rattlehedchris - I'll bet if you go out tomorrow and try and start your car it will start. The next time you take it for a drive and it won't start after shutting it down, press the pedal to the metal holding the accelerator to the floor and try and start it. It will probably start up after a few cranks.

With that said, it still isn't working right so Cliff's suggestions are probably right on.

Cliff, can you try and explain what is happening when the car will not start after setting for 30 minutes or so after the engine was good and hot? And please explain why flooring it while cranking seems to clear out the excess gas or no gas, whatever is happening?

[rattlehedchris]

I tried giving it gas, flooring the pedal, among other things to try to start it. I think it is the external vent near the accelerator pump on top of the carb. Reading about it made perfect sense to me, esp. since there was some silicone on the outside on top of the accelerator pump shaft, I guess whoever put it on there thought the thing had to be perfectly sealed there, which it doesn't, even with the amount of wear on my carb. Gas and silicone do not mix, and when I scraped it off, some may have fallen in the holes of the vent and gummed up in there. Any suggestions on fixing this with the carb on the car? Wondering if I should spray something in there?