6066 (1960-1966) GMC Truck Club Bitcoin now accepted here! 
Pay Dues
Pay Dues or become a Site Supporter
 



Go Back   6066 (1960-1966) GMC Truck Club > 6066 GMC Truck Club Forum > GMC V6 and V12 Engines


GMC V6 and V12 Engines Engine repair and rebuilding

Reply
 
Thread Tools
  #1  
Old November 6th, 2015, 06:01 AM
acerna acerna is offline
Junior Member
 
Join Date: Mar 2013
Location: san antonio,tx
Truck: 61 v6 gmc
Age: 77
Posts: 6
Rep Power: 0
acerna is on a distinguished road
Default truck won't start

I have 61 GMC v6 305 that wont start. Last time started was about 3 months ago it back fired and didn't re start. I have replace the canister type fuel filter and the inline fuel filter also. Have used two different fuel pumps 9 O' Reily and Napa and still no go. Have disconnected the fuel line and gas gets to the fuel pump and not to the carb. Tomorrow i will prime the carb with gas and see. Please any suggestions.
Reply With Quote
  #2  
Old November 6th, 2015, 01:56 PM
abus319 abus319 is offline
-= Site Supporter =-
 
Join Date: Sep 2013
Location: Austin Texas
Truck: 1960 3500, 305D heads
Posts: 116
Rep Power: 95
abus319 is on a distinguished road
Default Re: truck won't start

Acerna
Hopefully someone with more skill than I have will chime in soon, but Backfire can be several things. Usually its related to timing, but can also be a lean fuel condition as you suspect. I don't know which carb you have but putting an ounce of fuel into the air horn instead of dumping it down the venturi is a much safer approach and will give you a longer run time. That should be enough time get your fuel pump going.
These new fuel blends have a VERY limited shelf life so if it sat very long before you tried to start it 3 months ago you will probably have more work to do.
I have to pick up a grinder in San Antonio so If you need help or just want to chat I will pm you my number.
Oh and a fire extinguisher is a great tool to have nearby
Reply With Quote
  #3  
Old November 6th, 2015, 07:22 PM
George Bongert George Bongert is offline
Senior Member
 
Join Date: Jan 2013
Location: Oshkosh Wisconsin
Truck: Former owner Repowered by GMC 305 V-6, 1963 Chevy 30 Series SM420 Long Bed (9') Step/Fenderside
Posts: 210
Rep Power: 141
George Bongert will become famous soon enoughGeorge Bongert will become famous soon enoughGeorge Bongert will become famous soon enough
Default Re: truck won't start

Greetings!

Since you are getting fuel to the fuel pump but not the carb, my suggestion is to check the inline filter installation. Inline filters are designed for the fuel to only flow through them one way. If the inline filter is installed the wrong way could be your problem.
Reply With Quote
  #4  
Old November 6th, 2015, 09:04 PM
AZKen's Avatar
AZKen AZKen is offline
Senior Member
 
Join Date: Jul 2014
Location: AZ
Truck: 6066GMC
Posts: 1,605
Rep Power: 513
AZKen is just really niceAZKen is just really niceAZKen is just really niceAZKen is just really niceAZKen is just really niceAZKen is just really nice
Default Re: truck won't start

Agree with the others and agree with your efforts. Need to know if there is a filter between pump and carb. Need to know if you see no fuel coming out of pump output line when placed into a jar, while cranking for 15-25 sec, distributor center wire disconnected. If there is no fuel getting to carb, there is nothing to be gained by pouring gas down carb yet. You must do a proper pump flow test with no filters involved first.
I guess if you are curious if it will start/fire knowing no fuel is getting to carb, it's up to you. At least you will be happy if it starts/fires.
If no fuel at pump outlet (without filters)= bad pump, pump arm not aligned, air leak in hoses/lines, tank plugged, tank not vented. Not sure if all above will cause, just mentioning everything I can think of.
Should have a pretty strong pulsing squirt and start to fill jar pretty quick if battery and starter are up to snuff.
CAUTION: Fuel at the pump inlet can be deceiving. There will be a trickle or a dickle there but that does not mean the pump is getting enough fuel. Besides what George said, be sure there is gas in the tank, aye?

Last edited by AZKen; November 6th, 2015 at 11:05 PM.
Reply With Quote
  #5  
Old November 7th, 2015, 04:28 PM
Jim A Jim A is offline
Senior Member
 
Join Date: Jan 2013
Location: Potter Valley, CA
Truck: 1960 3/4, 4 spd, stepside
Posts: 136
Rep Power: 109
Jim A is on a distinguished road
Default Re: truck won't start

Just to be sure the problem is fuel, take two minutes and put an old sparkplug on any plug wire, ground it and check for spark.
I have been fooled a few times over the years.
Good luck.
Reply With Quote
Reply

Bookmarks

Thread Tools

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


Similar Threads
Thread Thread Starter Forum Replies Last Post
Re: [6066 GMC Truck] Re: Still won't start Archiver Previous Forum Posts 0 October 11th, 2003 04:04 AM
Re: [6066 GMC Truck] Still won't start Archiver Previous Forum Posts 0 October 11th, 2003 03:03 AM
Re: [6066 GMC Truck] Still won't start Archiver Previous Forum Posts 0 October 11th, 2003 02:28 AM
Re: [6066 GMC Truck] Still won't start Archiver Previous Forum Posts 0 October 10th, 2003 12:48 PM
Re: [6066 GMC Truck] Still won't start Archiver Previous Forum Posts 0 October 10th, 2003 01:27 AM


All times are GMT +1. The time now is 04:37 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2013, Jelsoft Enterprises Ltd 681711554703|1710517021|0