Welcome! Please use the navigational links to explore our website.
PartsASAP LogoCompany Logo Auction Link (800) 853-2651

Shop Now

   Allis Chalmers Case Farmall IH Ford 8N,9N,2N Ford
   Ferguson John Deere Massey Ferguson Minn. Moline Oliver

Ford 9N, 2N & 8N Discussion Forum
:

85 GMC 1/2 Ton

Welcome Guest, Log in or Register
Author 
reddirtfarmer

11-11-2005 16:41:23




Report to Moderator

I know this is a Ford N series forum but, a bunch of you seem to have a lot of knowledge on various topics. I have a 85 GMC 1/2 Ton, 305 V8 and I'm pulling my hair out. I can jump in it some days and it kicks right off, other days it might sit for a week and never hit. Then, sure enough you get in it and it pops right off. Now I don't believe its the carb but something in the electrical system. When its running .... sometimes...it will just quit...like you turned off the switch.... and won't hit a lick. Let it sit for a day or two...try it again...kicks right off and runs like a top! Any ideas at all would be much, much appreciated. By the way, I just got my steering section on my 51 8N rebuilt. Thanks for all the information on that as well!!!!!

[Log in to Reply]   [No Email]
lonestarjeff

11-12-2005 08:20:14




Report to Moderator
 Re: 85 GMC 1/2 Ton in reply to reddirtfarmer, 11-11-2005 16:41:23  
Not sure from your post if the engine won't turn over at all or it just won't start.

If it's the latter, there's one other thing you might try. My 86 K-5 & Dad's 85 Silverado both have the 305 & had a similar problem. The HEI distributer has a vacuum spark advance. Over the years the rotation of the cap would wear thru some wire insulation inside the cap causing an intermitant short in the ignition circuit. Unplug the vacuum hose to the distr. under the left side of the breather(as you look in the engine bay). Make sure you plug the hose on the engine side.

Jeff

[Log in to Reply]  [No Email]
K,LaRue-VA

11-11-2005 19:16:29




Report to Moderator
 Re: 85 GMC 1/2 Ton in reply to reddirtfarmer, 11-11-2005 16:41:23  
Think you are right, this has all the symptoms of an electrical glitch. I agree with the bad ignition switch theory, but you might want to trace the harness and make sure it aint something simple like the coil or points wire going to ground. Had one do that one time on a piece of accelerator linkage, and it about drove me nuts, till I found it.



[Log in to Reply]  [No Email]
MichaelNEIowa

11-11-2005 18:42:49




Report to Moderator
 Re: 85 GMC 1/2 Ton in reply to reddirtfarmer, 11-11-2005 16:41:23  
My 98 gmc k2500 did something similar. In my case, the truck would start and run fine and I"d be driving and it would just quit. Dealer finally traced it down to the ignition switch. In the switch were some contact points that were badly worn and thus would cut the circuit.

A new switch/wiring harness to the firewall fixed it and now it works great.



[Log in to Reply]  [No Email]
JimNC

11-11-2005 18:10:36




Report to Moderator
 Re: 85 GMC 1/2 Ton in reply to reddirtfarmer, 11-11-2005 16:41:23  
I had a bad battery cost Me over $150. I "fixed" a whole bunch a sh!t that didn"t need fixin". Now I just call Hobo,NC. I"m almost close to being a relative, cause I only call him when I need sumpin" :>}


Jim



[Log in to Reply]  [No Email]
Hobo,NC

11-11-2005 18:30:42




Report to Moderator
 Re: 85 GMC 1/2 Ton in reply to JimNC, 11-11-2005 18:10:36  
Yep we are creek cuzzins



[Log in to Reply]  [No Email]
Hobo,NC

11-11-2005 17:51:55




Report to Moderator
 Re: 85 GMC 1/2 Ton in reply to reddirtfarmer, 11-11-2005 16:41:23  
If it has electronic spark controll (4 wire conector at Dist.) with out check'in my notes,s jump the A and C terminals on the distributor side of the ESC connector this will by pass the spark control puter. Its ok to leave it this way.
replace the rotor button also. Fuel pumps have been a problem on'em to but you should be able to eliminate that.



[Log in to Reply]  [No Email]
reddirtfarmer

11-11-2005 18:03:28




Report to Moderator
 Re: 85 GMC 1/2 Ton in reply to Hobo,NC, 11-11-2005 17:51:55  
I'll try that....thanks!!



[Log in to Reply]  [No Email]
old

11-11-2005 16:56:38




Report to Moderator
 Re: 85 GMC 1/2 Ton in reply to reddirtfarmer, 11-11-2005 16:41:23  
Sounds like the module in the dist maybe going bad on you. I've seen that type of problem with them before. When they go bad they do some real funny things.



[Log in to Reply]  [No Email]
reddirtfarmer

11-11-2005 17:02:02




Report to Moderator
 Re: 85 GMC 1/2 Ton in reply to old, 11-11-2005 16:56:38  
A friend told me the same thing, replaced it with a new one to no avail!



[Log in to Reply]  [No Email]
old

11-11-2005 17:20:03




Report to Moderator
 Re: 85 GMC 1/2 Ton in reply to reddirtfarmer, 11-11-2005 17:02:02  
Could also be the coil, since you replaced the module.



[Log in to Reply]  [No Email]
reddirtfarmer

11-11-2005 18:05:09




Report to Moderator
 Re: 85 GMC 1/2 Ton in reply to old, 11-11-2005 17:20:03  
just didn't think about that....I'll try that as well..... Thanks!!!



[Log in to Reply]  [No Email]
stimw

11-11-2005 18:46:43




Report to Moderator
 Re: 85 GMC 1/2 Ton in reply to reddirtfarmer, 11-11-2005 18:05:09  
Some GM vehicles had low oil shut down. If the oil sending unit has 3 terminals (I think) it might have it. If the sending unit acts up you have no power to the ignition even with oil pressure.



[Log in to Reply]  [No Email]
[Options]  [Printer Friendly]  [Posting Help]  [Return to Forum]   [Log in to Reply]

Hop to:


TRACTOR PARTS TRACTOR MANUALS
We sell tractor parts!  We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today. [ About Us ]

Home  |  Forums


Copyright © 1997-2023 Yesterday's Tractor Co.

All Rights Reserved. Reproduction of any part of this website, including design and content, without written permission is strictly prohibited. Trade Marks and Trade Names contained and used in this Website are those of others, and are used in this Website in a descriptive sense to refer to the products of others. Use of this Web site constitutes acceptance of our User Agreement and Privacy Policy

TRADEMARK DISCLAIMER: Tradenames and Trademarks referred to within Yesterday's Tractor Co. products and within the Yesterday's Tractor Co. websites are the property of their respective trademark holders. None of these trademark holders are affiliated with Yesterday's Tractor Co., our products, or our website nor are we sponsored by them. John Deere and its logos are the registered trademarks of the John Deere Corporation. Agco, Agco Allis, White, Massey Ferguson and their logos are the registered trademarks of AGCO Corporation. Case, Case-IH, Farmall, International Harvester, New Holland and their logos are registered trademarks of CNH Global N.V.

Yesterday's Tractors - Antique Tractor Headquarters

Website Accessibility Policy