Problem Idling After Not Running For a Month

[Mr_T]

Howdy:

I just finished bolting everything back in place after replacing the clutch and flywheel on my 78 GMC K15. The job took longer than I had anticipated between work and vacation and the truck hasn't run for about 1.5 months. Now when I turn it over it will start but is rough and won't stay running without some light gas pedal. As the engine warms it has a harder time staying alive so I haven't run it for more than 30 seconds at a time. I've turned it over a few times over a few days and the situation hasn't improved.

It's getting gas but the gas is a little old. I put some stabilizer in the primary tank and put about a gallon of fresh gas in the nearly empty secondary tank. I've been starting it with the secondary tank.

I replaced the spark plugs today one by one and squirted some oil inside each cylinder to make sure they're getting lubed since I figure the oil is sitting at the bottom of the pan.

I removed, cleaned, and reinstalled the after market fuel filter just before the carburetor.

No results and I'm fresh out of ideas after browsing the repair manual and the forums. Any recommendations?

[smpoulin01]

How was it running previously? You check for any corrosion in the cap? Check for a sticky float?

[wilkin250r]

I'd start running through the checklist, I'd probably start with vacuum pressure (looking for a vacuum leak), and timing.

[El Dorado Jim]

sounds like carb issue, put some seafoam in your tank and run it ....will help clean out the crappy gas and buildup from the gas

[Mr_T]

Originally Posted by smpoulin01

How was it running previously? You check for any corrosion in the cap? Check for a sticky float?

Running very well previously. The truck is new to me but it would turn over after the normal chug chug and gas pedal pumps. Once it fired up it never had an issue with idle.

Since the secondary is nearly empty I may consider dropping it to investigate. Next steps I think will be to put the secondary tank hose into my lawn mower gas can and see if I can get it running from there. That way I can isolate bad gas or not but it seems like the most probable cause.

I had been planning on putting in a new float and filter anyway for both tanks I was just hoping it'd be a little further down the line.

Thanks for the tips, I'll post an update!

[wilkin250r]

A month and a half doesn't sound like a "bad gas" problem to me. I've had gas sit for 6+ months, and fire right up.

By all means, test the theory and leave no stone un-turned. But I think the problem is going to be someplace other than your gas tank...