Car Dies After Driving for awhile. Carb Loads up?

[longdillon1]

Hi all. My vette idles a bit shaky and when I drive the car, after about 15 minutes, it dies. I have to hold th gas peddle to the floor and start it. It will then start and dies about a minute later. Is it the float in the carb? Just rebuilt the rochester quadrajet. Any and all help would be appriciated. Where should the float be measurement wise? What degree should the timing be at?
Thanks,
Dillon

 

[Dunzvett81]

Well it could be a number of things, however it sounds like a fuel issue. I would check the fuel filter, accelarator pump, fuel pump, vacuum lines, EGR valve. Stock timing is 6 BTDC. Most of the guys you will find advance them to 10-14. I have mine set at 10. Remember to disconnect your vacuum advance to set base timing

 

[longdillon1]

Well I did just remove all of the stock exhaust stuff for a true dual exhaust. Do I need to adjust anything for that>? I actually will change the fuel filter as I dont think I changed that yet. I also think I took the egr valve off. Anything else?
Thanks Again,
Dillon

 

[Dunzvett81]

The exhaust would not effect anything. From what you described it sounds like a fuel problem and is probably carb related. Sometimes it is just trial error before finding the issue.

 

[longdillon1]

Ok. Ill go ahead and change the fuel filter tomorrow. Ill also check the carb and lines. Thanks Again for all of your help.
Thanks,
Dillon

 

[TimAT]

Did you install a new float when the carb was rebuilt? Q/Jets have a little habit of the flaot getting saturated and being too heavy, causing problems like you describe. The float level is important too. THe sheet that came with the kit will have the correct setting.

 

[Hib Halverson]

Based on the limited symptoms presented I'm going to guess that the carb is either flooding due to improper float level or has leaking secondary well plugs.

You need to remove the carb, then remove its throttle plate and inspect the well plugs for evidence of leaking. If they are, they need to be repaired with one of the kits on the market for that purpose or the carb needs to be replaced.

As for flooding, your statement that you just rebuilt the Quadrajet followed by your question about float levels has me thinking that the instructions in "carb kit" you used for the rebuild were not consulted as to float level.

Find the instructions. Read the float level information then set the float in the QJ accordingly.

Take the appropriate action, road test and let us know how the car runs.

 

[LLC5]

Did you install a new float when the carb was rebuilt? Q/Jets have a little habit of the flaot getting saturated and being too heavy, causing problems like you describe. The float level is important too. THe sheet that came with the kit will have the correct setting.

Sunk floats are a common problem with Q-jets, I always replace them when rebuilding one. You can epoxy the well plugs when you remove the carb, but the problem does sound more like a saturated float or level, or debris under the needle and seat. I am assuming the needle and seat are new?

 

[LVMYVT76]

Could it be the choke?

 

[longdillon1]

Ok everybody. sounds like it is the choke, float or needle. Ill check those and update you guys.
Thanks Alot

 

[LLC5]

Could it be the choke?

Good point. Make sure the choke is held open tightly when fully warm.

 

[gmjunkie]

Did you install a new float when the carb was rebuilt? Q/Jets have a little habit of the flaot getting saturated and being too heavy, causing problems like you describe. The float level is important too. THe sheet that came with the kit will have the correct setting.

Based on the limited symptoms presented I'm going to guess that the carb is either flooding due to improper float level or has leaking secondary well plugs.

You need to remove the carb, then remove its throttle plate and inspect the well plugs for evidence of leaking. If they are, they need to be repaired with one of the kits on the market for that purpose or the carb needs to be replaced.

As for flooding, your statement that you just rebuilt the Quadrajet followed by your question about float levels has me thinking that the instructions in "carb kit" you used for the rebuild were not consulted as to float level.

Find the instructions. Read the float level information then set the float in the QJ accordingly.

Take the appropriate action, road test and let us know how the car runs.

Sunk floats are a common problem with Q-jets, I always replace them when rebuilding one. You can epoxy the well plugs when you remove the carb, but the problem does sound more like a saturated float or level, or debris under the needle and seat. I am assuming the needle and seat are new?

 

[longdillon1]

Well now the car backfires and wont idle to good. So I think im just going to replace the carb with an edelbrock. Any idea which one would be best for a stock application?
Thanks Again,
Dillon

 

[minifridge1138]

You're about to get a lot of different opinions.
Most will tell you that the best you could do is get the Q-Jet rebuilt.

They are probably right.

 

[motorman]

if your corvette has a fuel pump return line to the tank make sure that it is not plugged as this will raise the fuel pressure at idle and cause flooding of the carb.

 

[longdillon1]

well the carb was rebuilt. i think It just needs to be tuned. Im going to check the return lines. Thanks everybody for your help.
Thanks