Uneven run, low revs, white smoke

[Mark]

Chris,
Have you done any work on your tractor in the last 6 months? You do have a conundrum for sure.

Have you worked on your injector pump? What about the return line from the injectors back to the fuel tank? It may be stopped up, but I don't know if that would do what your describing. What about the fuel, is it new or old? Is there any water in the fuel somehow. Have you drained the whole fuel system to get out all the creepy grud? I'm just thinking out loud here to try and help you.

Can you borrow a compression tester from someone instead of having to buy one? I don't think there all that much, I saw one today at a Sears store for $29.00.

The white smoke would mean your tractors burning water, but the low revs sounds like the diaphragm in the governor, but then again it's usually a high rev problem. Have you checked the diaphragm in the secondary fuel pump? There are two check valves inside the housing, has anyone messed with them? Maybe switched them around?

I believe somewhere it's starving for fuel, and there's water in the fuel from somewhere.

I wish I lived close I'd come and help you figure this out. I hope some of this jabbering helps.

[chrism0dwk]

Hi Mark,

Thanks for the suggestions. My local tractor mechanic advised me to check the tappets as well as the fuel bleed-off from the injectors. Tappets were all a bit tight, but resetting them made no difference. I checked for a blocked bleed-off pipe by slackening the banjo bolts on all three injectors -- again, no difference.

Really, this seems like a misfire issue, as well as the engine running "hard". The thing I can't quite understand is why the problem seems to go away if the revs are high and the tractor is working hard -- the white smoke clears, and the engine sounds a little more even. This happens if I'm mowing, and the slasher goes through a slightly thicker patch of grass at the same time as the revs (for whatever reason) are randomly a little higher. The engine will run okay for a bit, but then return to dropping revs and white smoke. The engine is still really easy to start -- doesn't that mean that lift pump and/or fuel feed problems are unlikely?

Looks like another call to my LTM, who said he'd tell me what to do next...

Cheers,

Chris

[Mark]

Chris,
Have you had the injector pump apart or off your tractor lately? Let me know what your mechanic says, I'd like to know.

[chrism0dwk]

Hi Mark,

Well, over the phone the mechanic reckons it's what you guys have been telling me all along: a fuel issue. He's coming out tomorrow, so I'll report back. I'll bet that either I've overlooked something stupid (most likely!) or it's the injection pump. I sincerely hope the former!

Chris

[Mark]

Sounds like a plan.

[chrism0dwk]

Chaps,

I feel terrible about this, and hang my head in abject shame! Quite how I managed this, I can only guess. I apologise profusely for having wasted peoples' time, BBS hard drive storage, and general internet bandwidth. I relinquish my "Not Quite Blue Yet" status for "Less than Numpty".

It turns out that the trouble with my Super Dexta was fuel contamination. The diesel was so contaminated that it was, in fact, 100% petrol.

I cannot believe how stupid I was. The only upside -- I now have a working tractor, and 5 gallons of petrol to use up in my motor mower.

Yours in shame,

Chris

[Brian]

No need to hang your head Chris, we have all done something similar.

It is called a "Learning Curve"!

[Mark]

Chris,
Brian is 100% right, we all have made mistakes and learned great lesson's from them. You're not the first person to do this, nor will you be the last. Just laugh it off and let it go.

I'll tell you a little story: My neighbor needed to grade his driveway one day many years ago, he called and I was just leaving to go to town. I told him to just come over and get it and do the work himself. After he worked my tractor for several hours he filled it up with "fuel" before he brought it back. Now keep in mind that this neighbor has ran tractors and bulldozers most of his life. On his way back to my house the tractor started sounding terrible, he almost didn't get it home. To make a long story short, he had filled it up with gasoline/petrol, I figured out what he had done and drained it all out and filled it up with proper diesel fuel, and she ran fine after that. Needless to say my neighbor was so embarrassed because he had so much experience with tractors, and to not have known by the sound that it was a diesel. He and I have laughed about this for years.

[marcusgs]

Chris,

Over here in good old England we have something called bio-diesel, a percentage of which is added to normal diesel, and we have had several cases at work where this has solidified into small balls, and killed injector pumps on our fleet of forklifts.

I have to say that it did cross my mind that you might have water in your diesel or something similar, as I was reading along, but thought that that would have been the first thing you checked.

It's easy to discount the obvious, as, well, obvious but sometimes the obvious is the thing that we all miss.

You've given us all a great fault finding reference on here, and I for one have enjoyed reading, and the anticipation of waiting for your update telling us that you got sorted.

Now enjoy your blue friend

[Jerry Coles]

Well I filled by Peugeot 306 with Petrol - it conked out 8 miles later!!
Pumped out the petrol and drained everything, filled up with Diesel, bled it and it started!! The funny thing was that it now ran much better!! Could the petrol have washed out all the gum and muck from the FIP and Injectors?

My friend only last week asked me to look at his chainsaw (Stihl 390) as he couldn't start it! He pulled it and pulled it, asked me to pull it and sure enough it wouldn't start. Checked the fuel tank - empty!!
If what we do in error doesn't do any damage then fine you've learnt a lesson, if you do do damage then it's a bigger lesson to learn.
Jerry

[Brian Cox]

Hi Chris, have you tried running with the fuel tank filler cap off, I had this problem some time ago with a fergy, problem was air lock

[chrism0dwk]

Hello everybody,

Well, Dex appears to be running really well now I've got her drinking diesel. Really clean burning, not a whiff of smoke, and running a little cooler than on petrol (I suspect because the engine, and therefore the water pump, is running at a proper speed). On with the mowing, and the continued restoration.

Cheers, and thanks for all your comments. As you say, Brian, I hope this thread serves as a good fault finding reference -- I'm tempted to write it up as a wiki article, actually.

Chris

[Brian Cox]

Hi chris, I had a problem a few years ago with a Fergy took the fuel cap off and away she went. You never know until you try, the vent in the cap was choked so try it