6500 problem

[cowsmowmygrass]

This is a test I am capable of doing. Than you Harry. I agree with your diagnosis. It MUST still be a fuel flow issue. Your test method seems very indicating of the potential problem. I will report what I find next here.

 

[cowsmowmygrass]

My experiences with Mahindra tractors has shown that this particular symptom can be caused by at least two separate problems. One is fuel blockage/starvation due to restriction somewhere. Another is the pump timing issue. My observations of each show the smoke puffs with timing problems will be more blue/gray in color while fuel supply problems cause the color to be closer to white. Timing issues usually occur within the first 150 hrs of operation, you must be well beyond that. With the timing problem, the condition most often comes on after the cold start timer goes off(about twenty minutes), and can continue until the engine is switched off and restarted. It will often return after another twenty minutes or so. The blockage problem can occur at any time, so stopping and restarting the engine will have little or no effect. I suspect your problem is supply related, and would suggest you place a pan below the fuel filter assembly and remove the banjo bolt from the outlet fitting( the line leading up to the injection pump) and observe the flow for a minute or so. Since the filter base is mounted low, the fuel will gravity feed at a good rate. It should continue at this rate until the tank empties, and not quickly reduce to a trickle. This may give an indication of where to go next.

:thumbsup:
First, Harry how do I mark your post as 'sticky' or very useful. Your reminder to approach this problem with logic is refreshing.

Outcome - fuel flows freely up to the hand pump

Details follow
I chose "fuel blockage/starvation due to restriction somewhere" because
1. I remembered the smoke being closer to white than blue/gray
2. My 6500 has about 225 hours
3. stopping and restarting had no effect
So , I did as you suggested
1. "remove the banjo bolt from the outlet fitting( the line leading up to the injection pump) and observe the flow for a minute or so."
Result is a bunch of diesel on my hands making wy wife say 'ooooo yuk' when I come back in to type this. But, then the leaking diesel stopped. After checking that the petcock is open I realized that I still have a fuel blockage problem.
2. Next, I removed the banjo bolt from the inlet fitting. The steady stream of diesel did not stop. OK, got diesel to this point.
So, then I planned to open each bolt between here and the outlet fitting to isolate the blockage.
3. The primaty filter(closest to tank) drain flowed freely
4. The secondary filter(closest to pump) drain flowed freely.
HUH? The blockage is between the secondary filter and the outlet? There isn't any other opening to check between these two points. The only thing between them(sort of) is the hand pump. Asked myself, how can the pump be restrictive?
I opened the pump handle and got a little faster stream from the secondary filter drain.
I operated pump 1 stroke and got a face of diesel. Oh yeah. The outlet banjo bolt is still removed.
So, fuel flows freely up to the hand pump. What is blocking it between beyond here?
Remember earlier I had operated the hand pump when tractor was running but sputtering. The hand pump had a vacuum on it. The upstroke was resistant. The downstroke was not restrictive.
Does the entire filter base have to be removed next? Any precautions to doing this?

 

[cowsmowmygrass]

[video]https://skydrive.live.com/redir?resid=932897728B6597E9!294[/video] Here is a video demonstrating the 6500 running with constriced fuel line.

 

[cowsmowmygrass]

Here ia a picture and diagram of my Mahindra 6500 Fuel Filter Base.
I will be following Harry's suggestions.

View attachment MahindraFuelFilterHousing.pdf

 

[cowsmowmygrass]

Harry in Ky wrote this:
I would proceed as follows: turn off the fuel valve at the tank outlet. Remove primer pump(the whole assembly should unscrew from the filter base). Open the valve a few turns and watch what happens. I would expect fuel to escape at a good rate. I believe this is a Bosch type primer pump, with two check valves involved. Simple theory here; pump plunger is lifted upwards - vacuum is created under it opening the inlet check and fuel flows in. Plunger moves downward - pressure builds, pressurized fuel opens outlet check and fuel flows towards outlet. In your case if the plunger shows resistance to being pulled up, it indicates that the passage through the inlet check and into the pumping chamber is somehow restricted. I think the pump assembly is no more than the plunger unit, and suspect the check valves will be in the filter base below, but I hesitate to say for sure. Once the pump has been removed you should be able to figure that out. I believe the primer pump circuit is merely a parallel circuit to the fuel flow through the filters, and may be between the supply and the primary filter, or between the primary and the secondary filter. I've never had to examine one to know for sure. You may have to remove the entire filter base, but I'd start by removing the filter cans first and looking at the inside of the base with a small hand mirror, and go from there. With both cans off, and the valve opened, you should get plenty of flow. Maybe try leaving the secondary can off and try the hand primer for effect? The problem must be in there somewhere.

 

[cowsmowmygrass]

[video]https://skydrive.live.com/redir?resid=932897728B6597E9!294[/video] Here is a video demonstrating the 6500 running with constriced fuel line.

This video was taken a few months ago as soon as I got the Mahindra back from the dealer, Top Flight, after they 'fixed' it. I have not run it with it smoking like this. My weeds are tall. My hay is unstacked. Beginning to get serious around here.

 

[cowsmowmygrass]

Yes, chronic fuel contamination continues.
Review of highlights for those just joining.
Engine starts, runs fine, accelerate to PTO 540 rpm. Brush hog for 10 minutes and then sputtering and white smoke. See video at
https://skydrive.live.com/?cid=932897728b6597e9&id=932897728B6597E9!294&sff=1
1st - suspect fuel flow restriction. Remove the banjo bolt closest to the inlet of the 2-can filter base (left side, beside starter). Fuel should gravity flow at a steady stream non-stop. This is also one option for draining the fuel into a container to empty the tank for cleaning, inspection, etc.
2nd - if fuel is slow or inerrupted, then a blockage occurs between here and tank. Opening the fuel tap at the bottom of tank is only option to further diagnose and repair. Drain tank into fuel container. If not possible, get ready to be covered in diesel and quickly plug the hole with something - I used a wine cork shaped to plug it, though still slightly leaked but I only needed it there a few minutes.
3rd - Remove fuel tap, which will have the in-tank screen attached, with an open-end wrench(I think 15mm)

 

[cowsmowmygrass]

Observed the in-tank fuel screen. What is clogging it?
Mine is a lot of scuzz out of the tank: brown paste -is it rust?
I removed the filter for further diagnosis. The primary can filter will catch everything, so I surmised to run it for a while without this main restriction.
Ran another 10 minutes, then chronic problem all over again.
Now, I find oatmeal sized rust flakes when I remove fuel tap. What is in the tank?. Drained remaining fuel. Rinsed tank with water and dried thoroughly first time. This all happened again, found rust flakes and brown scum paste. Rinsed tank again. This time with gasoline.
Have followed with 6 iterations of running for 10 minutes until it sputters, remove the fuel tap(still have not reinstalled screen) and unclog banjo bolt.
These events happened over a 3 month period.
Today, the Mahindra is stalled in the pasture. Time to go through it all once again. Poor wife, she hates the lingering smell of diesel on me when I do this. I don't like it either.

What could be contaminating the diesel?
How should the tank be cleaned without removing it?

 

[DavesTractor]

I'd suggest you pull the tank and clean it. It's a chore, but so is having a recurrent problem. We have found no good way to really get a tank clean without removal. Also check your fuel source for the possibility you are introducing contamination into your tank when filling. People that pump fuel out of 55 gallon drums will often be surprised to find their drum has a bunch of water and rust in it.

 

[BobG_in_VA]

If you pull the tank, suggest you get in touch with your local radiator type shop...they can clean and coat the inside of the tank so that no further contamination will occur from the tank...this won't help if you have fuel that is somehow contaminated...sorry to hear about your issues...I know thay are a bear to deal with.. BobG in VA

 

[LAWALLSTRACTOR]

Dave is right, your only choice is to now remove the tank, and as Bob said a good acid cleaning and a coating would be a very good idea.

 

[cowsmowmygrass]

If the interior of tank is rusting, I will be very disappointed in Mahindra. I don't have any other theory or explanation. I guess it's time to learn how to pull the tank.
I always compare this 2006 Mahindra to my 1969 IH. The IH has tolerated decades of the same fuel, same weather, same sun baking it but just keeps starting and running. When I have anything to do that the 40HP IH is capable of, I prefer it. Mahindra is falling in my rating. I'll reserve slamming them until after I see the actual condition of the tank.
Thanks to all for your help.

 

[cowsmowmygrass]

Also check your fuel source for the possibility you are introducing contamination into your tank when filling. People that pump fuel out of 55 gallon drums will often be surprised to find their drum has a bunch of water and rust in it.

I accept responsibility for a few years of fuel that could have been contaminated from the 55gal steel drum I used. For the last year though, it has had only highway diesel from 5 gal plastic jugs. No chance for rust from supply.

 

[bindian]

I accept responsibility for a few years of fuel that could have been contaminated from the 55gal steel drum I used. For the last year though, it has had only highway diesel from 5 gal plastic jugs. No chance for rust from supply.

Hey,
What side of Willis do you live? I am on the East side about 2 miles from the County Line "Y".
hugs, Brandi

 

[Jim Dodgins]

I know this is not going to help your immediate problem, but keeping your fuel tank topped off will help keep condensation from building up in your fuel tank and the eventual rust that can acumulate.

 

[DavesTractor]

Cowsmowmygrass, you can't hardly blame a metal fuel tank for getting rusty. If kept full and devoid of water, they won't rust. But keeping all water out is tough, hence the proliferation of plastic tanks on many models now. We just had an IH574 in the shop with rust holes in the tank, and we have replaced a pile of old Ford tanks. But of course they were much older tractors. You ought to be able to see in your tank with a flashlight. Most likely the tank is fine and is just polluted. It happens even to the most careful folks. Nobody sets out to pump water and rust into their tractor...yet it happens all the time.

 

[cowsmowmygrass]

Hi Brandi,
I'm on 1484 close to Cedar Ln.

 

[cowsmowmygrass]

Yes, a full tank reduces condensation and keeps the tank coated with diesel to prevent rust.
So, how important is fresh fuel?
Does it not deteriorate over time? How long can a tank be left in there and still perform?
In our humid climate, we have issues with algae also.
If diesel remains in the tank for a year, with just incremental amounts added a couple times during that year, what kind of issues will that cause?
Are some of the additives ok to use? keep the cetane up, prevent algae, remove water, etc.

 

[DavesTractor]

Yes, a full tank reduces condensation and keeps the tank coated with diesel to prevent rust.
So, how important is fresh fuel?
Does it not deteriorate over time? How long can a tank be left in there and still perform?
In our humid climate, we have issues with algae also.
If diesel remains in the tank for a year, with just incremental amounts added a couple times during that year, what kind of issues will that cause?
Are some of the additives ok to use? keep the cetane up, prevent algae, remove water, etc.

Good questions. I bet a fuel expert can chime in here and educate us all. Mahindra makes a fuel additive that does all of the above, or at least the label says so! We use it, but we are in a much drier climate so we do not see a lot of algae issues nor so much condensation. The Mahindra fuel additive comes in about a pint plastic bottle and it is good for about 500 gallons. I think it is 1 ounce per 32 gallons, so a quarter to a half ounce per tank would work well for you. I wish it wasn't so concentrated since my mind tells me I need to use more under the theory that if a little is good, more is better!

We have a 275 gallon tank we fill our tractors from and we just dump half a bottle in it everytime we fill that tank. So far, we have had no fuel issues. Keep in mind that these fuel conditioners can only disperse so much water. If you have a tank with a bunch of water in it, it needs to be cleaned out. I think the 6500 tank is a chore to remove unfortunately.

 

[bindian]

Hi Brandi,
I'm on 1484 close to Cedar Ln.

Wow, Your right around the corner from me. Dad and I had a deer lease between Cedar Ln and Browder Traylor Rd. with one side up on County Line. All of that now is subdivision. Let me know if you ever need any backhoe work. I'll cut you a big TBN discount!!!
hugs, Brandi