The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > 47 - Current classic GM Trucks > The 1973 - 1987 Chevrolet & GMC Squarebody Pickups Message Board

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 07-03-2017, 03:06 PM   #1
Mr_T
Registered User
 
Join Date: Apr 2017
Location: Houston, TX
Posts: 3
Problem Idling After Not Running For a Month

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?
__________________
1978 GMC K15, Sierra Grande
Mr_T is offline   Reply With Quote
Old 07-03-2017, 09:43 PM   #2
smpoulin01
Registered User
 
smpoulin01's Avatar
 
Join Date: Nov 2016
Location: Summerville, SC
Posts: 85
Re: Problem Idling After Not Running For a Month

How was it running previously? You check for any corrosion in the cap? Check for a sticky float?
__________________
85 Silverado - 350/700r4
smpoulin01 is offline   Reply With Quote
Old 07-03-2017, 11:14 PM   #3
Mr_T
Registered User
 
Join Date: Apr 2017
Location: Houston, TX
Posts: 3
Re: Problem Idling After Not Running For a Month

Quote:
Originally Posted by smpoulin01 View Post
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!
__________________
1978 GMC K15, Sierra Grande
Mr_T is offline   Reply With Quote
Old 07-03-2017, 10:13 PM   #4
wilkin250r
Registered User
 
wilkin250r's Avatar
 
Join Date: Sep 2010
Location: Lake Tahoe, Nevada
Posts: 755
Re: Problem Idling After Not Running For a Month

I'd start running through the checklist, I'd probably start with vacuum pressure (looking for a vacuum leak), and timing.
__________________
I know a little about cars, but if you have a question about electricity or sport quads, I'm your man!!!
wilkin250r is offline   Reply With Quote
Old 07-03-2017, 10:20 PM   #5
El Dorado Jim
Registered User
 
Join Date: Dec 2009
Location: El Dorado Ca
Posts: 3,374
Re: Problem Idling After Not Running For a Month

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
El Dorado Jim is offline   Reply With Quote
Old 07-03-2017, 11:51 PM   #6
wilkin250r
Registered User
 
wilkin250r's Avatar
 
Join Date: Sep 2010
Location: Lake Tahoe, Nevada
Posts: 755
Re: Problem Idling After Not Running For a Month

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...
__________________
I know a little about cars, but if you have a question about electricity or sport quads, I'm your man!!!
wilkin250r is offline   Reply With Quote
Reply

Bookmarks


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 10:03 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com