RTV900 Injection problem

[rwf642]

I have read all the forums and have not been able to solve my problem. Rtv will not start. No smoke! It turns over great.I have replaced the injector nozzles because we got some water in the fuel which caused the injector nozzles to freeze up (on a previous repair). I have a racor inline filter which is clean and the standard engine driven fuel pump which is providing fuel to the bleed screw on the injector pump. I also have low pressure fuel at the injectors when cracking the compression nut at the injector. fuel is going back to the tank through the return lines. No high pressure! I have removed the injection pump and inspected each of the 3 injector pumps for wear/debris and free movement, all passed. It would seem that at least one of the 3 injector pumps would be creating high pressure unless I'm missing something. I have removed the tank and cleaned it, hoses filters etc. The pumps seem to be fairly straight forward. I need some suggestions. I even sprayed a shot of you know what in the intake and no reaction. I don't want to have the pumps rebuilt if they're not bad. Any tests besides trying to spray the injectors in a jar. Don't have the capabilities to hook everything up out of its current position.

 

[bordercollie]

Hi rwf. Have you checked the stop solenoid? I will bump it too. This, when working, will make the little "tink " noise about 5 seconds after a properly running machine is turned off. You might try to manually see if you can get the little lever to move gently with your finger. Of coarse, it might well be some other problem but this is an easy fix so starting with it . bordercollie
edit: add link: http://www.nettractortalk.com/forums/showthread.php?t=14088

 

[rwf642]

Thanks for your response, the stop solenoid is working properly and I did check it. I read in another post that adjusting the idle speed was done with a lower screw near the fan blade. That screw would not be part of the injection pump but maybe there is a clog somewhere in that vein. I haven't looked to see that mine has those same screws but maybe its not in the pump itself?

 

[bordercollie]

Oh Shoot! I thought it might be an easy fix.The work"slop" manual has limited information on this in my opinion. Do you happen to have the manual? I might can scan those couple of pages for you if you need them. .It talks about the injection timing, rotating the flywheel etc. and also what the nozzle spray pattern should look like.also Factory spec on injection pressure: 13.73-14.71 MPa. The is a diagram of the injector (break down) and shows an adjusting washer( thickness ) on top of the spring.
. If you need it in a hurry , I do have a fax or I can scan and post in an album etc. Anyway, no problem to do it just pm me if you need it bordercollie .

 

[SpudHauler]

Remote possibility,

did you check your valve clearances.

no compression, no start.

Its a long shot.

 

[bczoom]

Are your glow plugs getting hot enough?

 

[rwf642]

Thank You for your input, I have not checked valve clearance. The valve covers have never been off. It happened suddenly. I parked it and next it wouldn't start. It started running a little under powered and had to feather a little on the last couple starts. I did not remove the fitting for the fuel line on the injector pump when I removed it. Is there a screen filter in that bleed fitting somewhere? I will remove the injector pump again Weds and clean and air out the bleeder valve. Maybe theres dirt in the valve body between the bleeder valve and the injector pumps? Any thoughts on that. It feels like theres not enough fuel in the injector pumps to create the high pressure. Does that sound reasonable?

 

[rwf642]

Glow Plugs

I pulled the glow plugs and put 12v from the battery and they get red hot. Re-installed them and applied 12v directly again and no start. I didn't mean to ignore your post on the last response but I just got carried away a little answering the valve adjustment reply.

 

[bordercollie]

While eliminating things, I would check the fuses too.

 

[rwf642]

I have checked the fuses out of habit but what would be electrical besides the shut off solenoid that might keep it from developing fuel pressure? Also thanks for your offer of pics from the manual. I do not have a shop manual on this unit. Any info you can share would be appreciated. I don't have a fax but e-mail would work.

 

[bordercollie]

Sure , I will get my scanner out tomorrow. By the way, I read somewhere that if the hyd lift lever is not in "neutral" it would not start on the newer models.. just thought I would also throw that out.. anyways , will get the pages scanned asap. bordercollie

edit>> I keep evading the low pressure thing ..... I was thinking the glow plugs' fuse.

 

[bczoom]

Any chance you're sucking air in somewhere?

 

[SpudHauler]

Kubota's troubleshooting guide might help give you some ideas. If you had the pump off, is it timed correctly when you put it back on. Not sure how that is done but will look in my manual to see if I can supply some more info.

Answer; No. I just looked in the manual and you most likely didn't go that far. That's the hard part about guessing, we can lead you in the wrong directions.

This is from the 1100 manual. Sorry don't have my old 900 manual.

 

[bordercollie]

I pm 'd you the link to the pages You can enlarge them there. bordercollie

 

[RealtreeRTV]

You mentioned some water got into system, how much water?
Water could have damaged injection pump. (water has no lubricating value to the close tolerance parts)

bczoom mentioned sucking air into fuel system, you can take the return line off
stick in in a bowl with fuel in it and watch for bubbles while cranking.

Mechanical fuel pump pumping OK?

Have you checked air intake? Make sure you haven't sucked in a plastic bag or something like that, to close off intake. That would explain not firing on spray that you mentioned.


Good luck!

 

[rwf642]

Thank You all for your help to resolve this no start issue. I am going to start all over with the inspection process. I did not put a fuel pressure gauge on the mechanical pump. There is definately fuel being pumped by the mech pump but is it enough pressure? I will check that with a gauge. I thought about the tolerances and the water. all of the parts inside the individual injection pumps are operating smoothly, when moved by hand so with the pressure of the spring it seems it should be ok. What do they rebuild on these simple pumps? There are only 3 o-rings and they seal fuel from leaking around the injector pumps. If the shims haven't been removed or changed it seems that they're pretty much bullet proof?

 

[rwf642]

Bordercollie- Thanks for the pages scanned there is some useful info there. If I work on this much more I may have to get one of these manuals. Looks like your is in CD!

 

[rwf642]

Realtree/BC- Sucking air could be an option. I'm not sure where, but leaning on those hose while working/inspecting could have cracked a hose somewhere. I will put new fuel lines on where I can and try to eliminate those possibilities. Thanks again for all your help, its nice to know there are guys that will take the time to think about someone else problems and try to resolve them. Now if congress would be so receptive we might be able to solve bigger problems.

 

[muleman RIP]

Pull the valve cover and make sure your valves are opening and closing. You may have a broken cam shaft.

 

[Mark.Sibole]

Check to make sure your fuel pump is functionable.It may not be pumping fuel or your fuel line going to the tank is plugged.I had to blow some gunk out on mine a while back.Even though I double filter all fuel going into my machine something still got stuck in the line right at the tank.