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

Case Tractors Discussion Forum

poor idle

Welcome Guest, Log in or Register
Author  [Modern View]

11-19-2023 14:52:42

Report to Moderator

hi, I have a David Brown 780 with poor idle. the engine starts nicely and has good throttle response, however the engine idles quite poorly and puffs out some white smoke. i have only just acquired it and I am fairly sure the diesel in the tank is quite old. and there is a wet spot around the number 3 cylinder. I think this could be the problem. combined with the old fuel. I am going to flush the fuel system and will change the oil. however before I go replacing the injector. I am wondering if anyone has any other suggestions of a lovely cause. I have already adjusted the valves. thanks.

[Log in to Reply]   [No Email]
used red MN

11-20-2023 09:48:50

Report to Moderator
 Re: poor idle in reply to woo003, 11-19-2023 14:52:42  
How does it sound when the starter is cranking the engine? I am not sure if I can train an untrained ear over the web. While cranking an engine that all the cylinders are fairly close on compression the starter will make a fairly consistent sound. If a cylinder has low compression the starter speeds up on that cylinder when there is less resistance from the lower or minimal compression in that cylinder. A cylinder with low compression could have symptoms like you are reporting. In this video at 9:45 you can hear an engine cranking with one bad cylinder. The tractor is a newer larger Deere, so maybe you will not be able to convince yourself that the sound can be applied to your tractor. Leave the fuel shut off when you try this. What or where is it wet around cylinder 3?

[Log in to Reply]  [No Email]

11-20-2023 02:59:54

Report to Moderator
 Re: poor idle in reply to woo003, 11-19-2023 14:52:42  
a heavy load on it.fesh fuel might add a quart automatic transmission oil to fuel
best fuel additive you can use

[Log in to Reply]  [No Email]

11-20-2023 11:33:52

Report to Moderator
 Re: poor idle in reply to r.w.b., 11-20-2023 02:59:54  
hi, thanks for both suggestions. I have added some injector cleaner and have flushed the fuel tank out. it seems to be running much better now. I will give it a bit more time to work to see if it fully resolves the problem. some online research has winded up with the suggestion of a cetane fuel booster. is this something anyone has experience with and weather it is safe to use in older engine. the engine did seem to have consistent compression because It cranked over smoothly and consistently.

however it seems like the tractor may need a new throwout bearing in the clutch. when the clutch is depressed. there is a whirring sound. I am fairly confident of this so I may split the tractor and replace it next time I have a free day. any tips would be appreciated about this. because it will be the first time I have split a tractor.


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

Hop to:

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