Carburator

[gop711]

Need Help,<br /><br />I had a friend try to rebuild my carburetor on my 4.3 V-6. It runs fine except it will not get above 3800 RPM. <br /><br />He said he replace the needle valve with the one in the kit. The old one had slits in it, where the new one does not. Could this be the problem? or Could it be that the float needs adjusting to let more fuel? He left that alone and it is just like it was.<br /><br />My original problem was that it would run fine then start to die and then die. It would start right back up and the process would start all over again. I clean the fuel screen in the tank before the carburetor was put back on. Anyway that problem is solved, I just do not have any power. Any suggestions?<br /><br />Thanks<br />Greg

 

[Chris1956]

Re: Carburator

Gop, It is hard to diagnose your problem with the information given. A fuel restriction (clogged filter, dirty tank screen, partially bad fuel pump..) would cause the motor to work well at low speed. As the RPMs increasse, the engine would starve for gas. Alternatively, If the carb floods, the inlet needle and seat may be the culprit. My '88 4.3LX has a fuel filter on the top of the fuel pump, as well as one in the fuel inlet on the carb. Make sure all are clean. If the carb is dirty, clean it with jet spray or soak it. Install the rebuild parts (usually just inlet needle and seat, accelerator pump and gaskets), and perhaps it will fix problem. You might want to test fuel pump when carb is off. Crank motor with a can under the fuel line. The pump should put out a specified amount of fuel in a specified time. See the manual for the specification.

 

[Bondo]

Re: Carburator

He left that alone and it is just like it was.

The Idea of a Carb. ReBuild is to Check,+ Verify the Tolerances.........<br />Go Back,+ Build it By the Book.......<br />What carb do you have ????<br />Chris is Right....<br />You May Well have Other Issues besides.....

 

[gop711]

Re: Carburator

Thanks for the suggestions. The carbueator is a Rochester Quadrajet. Prior to going into the carbueator I was getting max. rpm, then the engine would loose power and stop. I think the original problem was the fuel line in the gas tank. I took it out and cleaned it, as it had a good bit of trash around it. I tried to call the guy the was rebuilding the carbueator to ask him to wait, but it was too late. Given the fact that it was getting max rpm prior to the rebuild, do you still think it could be the fuel pump going bad? One more thing. When the motor is in neutral, I can get about 3000 rpm the trottle is only about 1/2 maybe a little more open. Again thanks for taking time to reply. Greg

 

[Bondo]

Re: Carburator

I can get about 3000 rpm the trottle is only about 1/2 maybe a little more open.

Without a "Load", It Really Doesn't Matter What the Engine Can do........