65 GMC Truck Idled nd now it doesn't

[mookiex4]

Hi all,

Had a question about my truck. I put a 283 into my 65 GMC 3/4 ton. I had it running and have been driving it for about a month now. all of a sudden last Wednesday it decided not to idle on its' own. It did seems that it needed additional timing with a light. I had to advance the timing to get it to run. It sat on an engine stand for about 30 years in my fathers garage before that.

I can drive it and it starts and runs fine just so I keep the idle up with the gas pedal. Once you let off it dies immediately.

I had the alternator tested. The guy ran it three times. It is OK.

I changed the fuel filter. The mechanical fuel pump is new and I even run a back up Electric one just in case I need it.

I set the idle adjusting screw down as far as it will go and still nothing. I had previously backed it off because it idled far to fast for my liking.

Could it nee to be retarded a bit now that it has been running and the timing is out now that everything has been lubricated and broken back in?

Could the carb need additional adjustment? Before it went in the carb was rebuilt, but I cannot guarantee the setting on the fuel and air mix.

Any help to point me in the right direction would be great. It has everything new form the point/condenser up to the spark plugs.

Thanks all.

[luvbowties]

Originally Posted by mookiex4

Hi all,

Had a question about my truck. I put a 283 into my 65 GMC 3/4 ton. I had it running and have been driving it for about a month now. all of a sudden last Wednesday it decided not to idle on its' own. It did seems that it needed additional timing with a light. I had to advance the timing to get it to run. It sat on an engine stand for about 30 years in my fathers garage before that.

I can drive it and it starts and runs fine just so I keep the idle up with the gas pedal. Once you let off it dies immediately.

I had the alternator tested. The guy ran it three times. It is OK.

I changed the fuel filter. The mechanical fuel pump is new and I even run a back up Electric one just in case I need it.

I set the idle adjusting screw down as far as it will go and still nothing. I had previously backed it off because it idled far to fast for my liking.

Could it nee to be retarded a bit now that it has been running and the timing is out now that everything has been lubricated and broken back in?

Could the carb need additional adjustment? Before it went in the carb was rebuilt, but I cannot guarantee the setting on the fuel and air mix.

Any help to point me in the right direction would be great. It has everything new form the point/condenser up to the spark plugs.

Thanks all.

First thing I'd check is for a vacuum leak.
Sam

[Irishbleueyes]

Could be anything, timing chain problem-distributor issue-something failed in the carb. Could have had an issue before you installed it, was it rebuilt and never used for 30yrs? Something maybe failed after rebuild? Did it have a dist. in it or did you install one? Maybe a bad wire somewhere in the engine bay somewhere? Good luck keep us posted

[jtrichard]

clean the carb you have a plugged idle jet i bet