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

Farmall & IHC Tractors Discussion Forum
:

M firing on only 3 cylinders, suggestions?

Welcome Guest, Log in or Register
Author 
unioncreek

02-23-2008 14:56:59




Report to Moderator

My M started running funny about a week ago after I ran out of gas. I thought it was a fuel problem so I cleaned all the screens and made sure the carb was clean inside. It didn't run any better so I started checking to see if it was firing, the #3 cylinder does not fire at all. The cap is a year old, I used an ohm meter and the cylinder tested good with continuity through the cap to the end of the spark plug wire. Point are opening and closing correctly. I'm wondering if it could possibly be the rotor. The #3 terminal inside the cap is blacker than the rest.

Any suggestions appreciated.

Bob

[Log in to Reply]   [No Email]
1fortyfanatic

02-26-2008 19:15:01




Report to Moderator
 Re: M firing on only 3 cylinders, suggestions? in reply to paulnde, 02-23-2008 14:56:59  
Ok, you don't have spark at #3. Like Jim up there said, swap wires and see if the problem follows the wire. If the problem remains on #3 ( I use the old method of a pair of gloves, pull the boot of the wire back and expose the tip, and holding the tip an 1/8th of an inch from the nearest bare metal while cranking. All possible safety measures taken of course, out of gear, brakes set, and someone on the key) then I'd have to say replace the rotor and the cap. Can't hurt if they're old anyway. Good luck and let us know what you find out.

Dave

[Log in to Reply]  [No Email]
1fortyfanatic

02-26-2008 19:07:48




Report to Moderator
 Re: M firing on only 3 cylinders, suggestions? in reply to Allan In NE, 02-23-2008 14:56:59  
Heheh, no Gordo, an IH 140 Offset fanatic. Although I am a Ford man when it comes to cars. I bet that was one fun ride! :)



[Log in to Reply]  [No Email]
kossuth

02-23-2008 17:51:24




Report to Moderator
 Re: M firing on only 3 cylinders, suggestions? in reply to Charles Todd, 02-23-2008 14:56:59  
I'd swap wires around first and see if the problem follows the wire or not. Could be that the contact or copper on that one wire is corroded through also. Give it all a good looking over and make sure it's AOK.



[Log in to Reply]  [No Email]
unioncreek

02-23-2008 17:22:43




Report to Moderator
 Re: M firing on only 3 cylinders, suggestions? in reply to unioncreek, 02-23-2008 14:56:59  
I checked all the wires for spark with my timing light, the number 3 wire is the only one that doesn't have any spark. Then I checked it with my ohm meter and there is continuity from inside the cap through the end of the spark plug wire.


Bob



[Log in to Reply]  [No Email]
old

02-23-2008 17:28:56




Report to Moderator
 Re: M firing on only 3 cylinders, suggestions? in reply to unioncreek, 02-23-2008 17:22:43  
I would replace the cap and rotor and see what happens. You could have a small crack in that area of the cap and a meter might not see the high voltage leak it would have if it has a crack



[Log in to Reply]  [No Email]
1fortyfanatic

02-23-2008 17:04:10




Report to Moderator
 Re: M firing on only 3 cylinders, suggestions? in reply to unioncreek, 02-23-2008 14:56:59  
While the diagnosis proceedure listed above is excellent, if you verify spark at all cylinders, then I would have to go with Gordo up there. Pull the valve cover (have a spare gasket handy) and check your push rods. If they are bent or slipped off the rocker arms, then you are not getting proper intake and exhaust into the cylinder, and it won't fire. When you run it a little and then pull the #3 plug, it should be wet from a lack of explosion. If you have spark (for sure) then I'd suspect the valve timing on #3 which is most likely due to the push rods having a problem. While you're in there, set ALL the valves to the spec clearances to prevent similar push rod failures in the future. Good luck!
Dave

[Log in to Reply]  [No Email]
GordoSD

02-23-2008 17:27:17




Report to Moderator
  M firing on only 3 cylinders, suggestions? in reply to 1fortyfanatic, 02-23-2008 17:04:10  
Would that be a 1940 Ford Coupe fanatic. I had one in high school. 3 Stroberg 97's on a flathead, aluminum heads, 3/4 race cam, headers, dual lakes pipes, Zepher floor shift tranny, moon hubcaps, tuck and roll upolstery, 30 coats of black laquer, flamed hood with Buick portholes, wide whites, nerf bars front and rear.Quite the rod! Second fastest rod in town. 47 business coupe Ford with a 55 Olds Rocket motor was THE issue to beat!

Gordo

[Log in to Reply]  [No Email]
GordoSD

02-23-2008 16:23:02




Report to Moderator
  M firing on only 3 cylinders, suggestions? in reply to unioncreek, 02-23-2008 14:56:59  
Pull the rocker cover and check the pushrods on #3. Also check the clearance set to .017. Sometimes a little bend in the rod, or a maladjustment will cause that rocker to slip off the pushrod.

Gordo



[Log in to Reply]  [No Email]
Janicholson

02-23-2008 15:26:41




Report to Moderator
 Re: M firing on only 3 cylinders, suggestions? in reply to unioncreek, 02-23-2008 14:56:59  
First is analysis.
Change the plug wire from one to another (both ends so it still is correct)
If the misfire follows the plug wire, there it is.
next
Change the plug from one cylinder to another Look at the two to see if different) If the misfire follows the plug, there it is.
Check the inside of the cap to make sure there are no carbon tracks, moisture, or cracks.
While it is running, use insulated pliers to pull the plug wire off of the ofending cylinder just a little bit. If it starts running on that cylinder, Suspect the plug.
If these do not help, I suspaec a compression check is next.
Then a manifolr leak check for vacuum leaks.
Then a Cylinder leakdown check. JimN

[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