Troubleshooting 165 Fuel System

[Tentman]

Hello Folks

My MF 165 (A4.212) won't start. Very embarrassing cause it (didn't) perform for my visiting brother-in-law, who has a collection of at least 7 MF's.

It cranks fine but with absolutely nothing from the injector pump, either in the form of white smoke, or fuel when the injector pipes are cracked off.

So I have checked the archives and taken the following steps:

Checked cut-off wasn't on and gave the throttle a workout to make sure nothing inside the injector pump was stuck

Replaced the fuel filters and cleaned pipe work from tank to injector pump (primary filter was completely blocked, bled system several times after this but still no go). There was a lot of water in the filters and fuel tank.

Removed the fuel tank and cleaned it (quite a bit of fine crud, plus a large bolt ?? inside)

Cleaned the fuel tank tap (crudded up with some gell stuff, also lots of Teflon tape !!)

I've also adjusted the tappets while the tank is off.

I checked all pipe work, and did find a loose fitting on the injector return pipe that goes back to the tank - would this stop the tractor from bleeding properly and running ??)

Tonight I'll check the functioning of the fuel lift pump and install a kit if necessary.

Is there anything else I should do, or that I have missed

 

[DavidP,South Wales]

Hi Foster,
Right you've done the main things. Starting at the tank, that's clean and the tap and strainer are clean. If you have not yet taken the top off the lift pump then that is a VERY strong possibility. It is a common problem with these pumps. It would be advisable to remove the pump and clean it out thoroughly. Ensure that you are able to re-use or make a new gasket before removal. With the pump cleaned and top refitted, operation by hand with a finger over in inlet you should feel the vacuum. It should also make a noise like a donkey (mule your side of the pond?). When refitted hand operation should give a good flow from the filters. Bleed in the normal way. Slacken at least two of the injector nuts and turn the engine over until you have fuel 'spitting' out.
It should then start. It is not uncommon to fail to start some tractors even with two batteries after the fuel system has been disturbed. It may well require a tow (rope only) to start it. Towing will produce a higher cranking speed. Once started you should have no problem after.

DavidP

 

[Tentman]

Thanks David, I'm to the point where a little encouragement is very welcome. Have now cleaned everything and replaced the lift pump. had a diesel mechanic friend over tonight but still no go (pity the modern guys, if it won't go all they can do really is think of replacing "modules"). We checked the pump to make sure the drive wasn't broken, and re-bled everything.

His mate (who is a real tractor mechanic) told us to use ether to keep it firing till it started, which is really just a very rough way of achieving what you suggested (can't tow it, its multi power). I'm not too keen on the ether so just put the battery back on the charger, and will assemble a bank of them tomorrow !!

Thanks

 

[Masseynut(Australia)]

Hi there,
You have spoken of Lots of "crud" in the system. If the filters were "crudded" up, some of it may have made it to the strainer, inside the fuel inlet union, in the rear of the injection pump. Is the pump bleeding ok, or lacking fuel at the lower bleeder, as well as the delivery pipes?

If the pump is "bleeding" ok, the problem may be a stuck "metering valve" in the injection pump, caused by the "crud". This should be repaired as necessary, by a fuel injection pump shop.
my 2 cents worth,
Evan.

 

[DavidP,South Wales]

Hello again,
Multi-Power....OK. I agree I would not use 'laughing gas'. For me it would be akin to 'gbh'on a MF!!! It's highly unlikely that its the cause but there is a small filter normally fitted at the rear of the pump where the fuel enters. In 35 years I have not had one blocked.

I would suggest that the next step is to remove the easiest injector pipe completely and refit it so that the pipe is sticking out from the side of the engine. Turn the engine over on the starter and observe the fuel output from the pipe. It should come in very specific 'spits'. If it comes out as a trickle or with very little force behind it then it would suggest that the pump is weak and probably not developing enough pressure to open the injectors.
When you try to start it with everything connected is there any evidence of smoke coming from the exhaust? If there is, listen to the pump. As the pump begins to build up pressure it will begin to 'tick'. Seconds after this the engine should spring into life. Have you got anywhere near this point? With plenty of battery power you will need to be aware that as the starter becomes warm and then hot it will loose cranking speed. If this happens go and have a cup of coffee while it cools.
Good luck
DavidP, South Wales

 

[Anonymous-0]

I've been fighting a rusty fuel tank since I rebuilt my engine. The tank sat empty for about a month and half. What I found is the cavitation fitting on the secondary filter gets plugged which causes bubble in the fuel to build up. This line come off the top of the filter and has a banjo fitting on it with a line going up to the injector and return to the reserve tank. Remove the fitting from the filter and blow some air through it you might need to use a smaal wire to clear it, maybe only .020" dia. Then bleed off the the lines as normal.

 

[Tentman]

Hello Guys - thanks for the input

Andy I can't wait to get home to try your idea re the return inlet banjo on the secondary filter. It has been very difficult to get a "clean bleed" on the inlet to the pump (stage 3 of the bleed acording to the manual). Often it seems like air was getting in somewhere to the secondary filter. I did find a very loose fitting on the front end of the injector return rail so maybe this has been the source of some "crud".

I was wondering if fuel will "cavitate" in a system to "create" air.

I'll also check that filter screen in the injector pump inlet.

Thanks again.

 

[Tentman]

Update . . . .

Took the filter screen out (and half the guts of the inlet metering, moral - don't use a screwdriver with a magnetic tip for this) an while it did have some fine crud, it was not blocked.

Discussed "issues" with a injector pump engineer and decided that it was probably a stuck metering valve. There are solutions to this suggested on the net including giving the pump a flush with ATF, but I decided enough was enough and have removed the pump to the engineers.

They confirmed stuck metering valve, and showed me how to diagnose - its a bit subtle but there is no tension or "feel" to the shut-off when it the metering valve is stuck. If you try it on a pump that is ok (with the actuating rod etc off as its a pretty subtle thing) then its easy to feel the difference.

Cheers

 

[Tentman]

Further Update - refurbished pump back and fitted last night (my work area is in a shed with no light, so I've had to rig a couple of lamps to work under, saying its not a well lit is a considerable understatement).

Doing the bleed at the injector pump I noticed diesel dripping off the block by my right elbow. Now after much gwarping by two diesel mechanics, myself with a fine tooth comb, and several other assorted onlookers of varying degrees of experience you'd think it a fair assumption that all leaks in the pipework had been found and fixed.

NOT SO. Yep there was a bloody great leak in the main supply line fron the secondary filter to the injector pump inlet. Not just a small leak either, the pipe was completely holed from a chafe where it passes over a support bracket for the block heater.

I was so disgusted I took the pipe off for repair and gave up for the night.

Guess I'm on a steep learning curve here.

Cheers - Foster

 

[peltsi]

Sound like you're getting close. Fix the leak, and it should be a starter

 

[Tentman]

All go now, diesel to the injectors in about 5 seconds of cranking, closed the pipes and another 5 seconds of cranking I had enough cylinders going to let the starter stop. By 10 seconds everything was away.

Now all I have to do is a few jobs like checking the thermostat while the panel-work is off and she'll be fully operational.

Thanks for all your assistance folks, much appreciated.

Cheers - Foster