D21 fuel smoking
Printed From: Unofficial Allis
Category: Allis Chalmers
Forum Name: Farm Equipment
Forum Description: everything about Allis-Chalmers farm equipment
URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=203558
Printed Date: 22 Nov 2024 at 6:00pm
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com
Topic: D21 fuel smoking
Posted By: ACman75
Subject: D21 fuel smoking
Date Posted: 07 Oct 2024 at 9:50pm
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So dads d21 we’ve been working over last few years and finally got it out and running it some,But it is smoking some. Heavier under more throttle. Not oil smoke though. Smells like fuel maybe. Could it be timing off a little. We bought this tractor “with motor built already”. Had a time ever getting it to crank first time until we figure out it was 180 on timing marks. So it’s hard to use timing marks. Also it will pop a little out of exhaust some times if you rev it up quickly. Also we had injection pump built by a local shop. Could it just be timing still a little off causing the fuel smoke? |
Replies:
Posted By: DrAllis
Date Posted: 07 Oct 2024 at 9:56pm
| D-21 engine injection pump (if that's what it is) shall be timed at 34 degrees BTDC. What are you timed at ?? If you think a D-21 is smoke free out the exhaust pipe, they are NOT. Valve lash needs to be adjusted to .017" COLD on intake and exhaust valves. |
Posted By: ACman75
Date Posted: 08 Oct 2024 at 7:43am
| Yes sir this is more than the normal d21 smoke. It’s a series 1 also |
Posted By: tbran
Date Posted: 08 Oct 2024 at 7:59am
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Hmmm, wonder if the pump shop used the series 2 fuel setting? ------------- When told "it's not the money,it's the principle", remember, it's always the money.. |
Posted By: DrAllis
Date Posted: 08 Oct 2024 at 8:10am
| Timing is set at what ???? Does it start really good on a COLD first thing in the morning start-up ??? |
Posted By: injpumpEd
Date Posted: 08 Oct 2024 at 8:24am
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Many shops don't understand how to assemble a DC pump properly, and therefore the timing mark ends up in the wrong spot. It will be difficult to time without taking the pump apart and correcting it. ------------- 210 "too hot to farm" puller, part of the "insane pumpkin posse". Owner of Guenther Heritage Diesel, specializing in fuel injection systems on heritage era tractors. stock rebuilds to all out pullers! |
Posted By: ACman75
Date Posted: 09 Oct 2024 at 9:51am
| Not sure on exact timing yet I’m not able to get back to shop yet. But the tractor cranks right up anytime hot or cold. Just touch the button |
Posted By: DrAllis
Date Posted: 09 Oct 2024 at 10:24am
| COLD starts do, in a way, indicate injection pump timing. Easy cold starting could mean retarded timing. Say, instead of 34 degrees BTDC you might be timed at 28 degrees BTDC and it would cold start wonderfully compared to 34 degrees BTDC. In the owners manual it even says for cold starts 50 degrees F or colder, the intake manifold heater will be REQUIRED to get the engine to start. Retarded timing will give poor performance and smoke as you increase engine RPM's, which is kind of what you are saying. I'm not there, but an experienced trained ear could diagnose retarded timing in 30 seconds of listening to the engine running. |
Posted By: ekjdm14
Date Posted: 10 Oct 2024 at 7:14am
In the first paragraph, do you mean over-advanced? It's been my experience of any diesel that they start cold best with more timing NOT less? Guessing it's a typo, but just seeking to clarify since my experience is mostly with smaller IDI units. Agreed a trained ear will pick up if the timing is off, generally RETARDED timing causes hard cold start/sweet grey-white smoke and a "lopey" idle in my experience. Also running quieter & less "diesely" sounding. Over advanced is a bit less easy to tell for me, but cold-starting "too well" is a fair indicator as mentioned. It'd generally make the engine a little more noisy too, a bit like mild injector knock. If it was mine, I'd want to reset the timing in order that your marks are aligned so you can verify timing 100%.
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DrAllis wrote:Posted By: WF owner
Date Posted: 10 Oct 2024 at 7:21am
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I am no where near as knowledgeable as Doc, but if I had excessive diesel smoke, the first thing I would check for is a restriction in the air intake system. You say this is a Series 1. Has it been upgraded (with a turbo) like many Series 1's were or is it still naturally aspirated?
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Posted By: DrAllis
Date Posted: 10 Oct 2024 at 7:41am
| We are talking A-C engines with Roosa-Master fuel systems. A D-21 will COLD start much easier at 28 degrees BTDC versus the recommended 34 degrees BTDC. That is 6 degrees retarded timing. |
Posted By: injpumpEd
Date Posted: 10 Oct 2024 at 7:53am
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With a pump with no advance mechanism in it. Most of the early allis with pump advance, like later 180, 185, 190XT, all 200/210/220 the pump advance is actually used as a start retard on them. So it lets the engine be timed to 8-10 degrees less, for better starting, but the advance is all in by 1000 rpm. Messing around with the pullers with inline pumps, they start pretty good at 30*, but get up closer to 40* better get the ether. Advancing the timing slightly does help the grey smokey haze they'll have once it starts though. Many pumps have a cold engine advance, not really for initial starting, but immediately after firing up. ------------- 210 "too hot to farm" puller, part of the "insane pumpkin posse". Owner of Guenther Heritage Diesel, specializing in fuel injection systems on heritage era tractors. stock rebuilds to all out pullers! |
Posted By: DrAllis
Date Posted: 10 Oct 2024 at 8:00am
| 28 degrees BTDC fixed timing (versus 34 degrees BTDC) on a D-21 gives you good cold starting, lower HP, more smoke and extremely high pyrometer temps under load !!! |