MF135 Diesel - Won't start after fuel gelling

Red135 · Jun 11, 2019

Hi all -

I've had an MF 135 diesel for about 20 years. Other than battery replacements and oil changes, it's required nothing. I use it less than I used to, so it often goes months without being started. Over the winter, I failed to put additive in the fuel and it gelled on me. I changed the filter and bled the lines but it didn't start at the time. I had more pressing issues and just got around to checking it out. I've bled everything again - and have fuel coming from the bleed points above all three injectors - but still not starting.

Is there anything else that might be preventing startup? Anything I'm overlooking, or any tips for troubleshooting?

Any help would be greatly appreciated.

Dieseltech · Jun 11, 2019

What do you mean, " I have fuel at the bleed points ABOVE all three injectors"? What needs done is each injector high pressure line nut loosened 1/2 turn, and crank engine until you see fuel at each loose fitting. When you see fuel tighten the nuts then engine should start. If you loosened the three small TOP injector return line bolts that does NO good. Also, what brand fuel filter did you use? If NAPA/WIX, did you put an O ring in the top outer groove, that should NOT be there?

Red135 · Jun 11, 2019

Hey Dieseltech... Thanks for the reply. You are correct in questioning my "above the injectors" bleeding. I was incorrectly loosening the connections for the return line back to the tank. So - thanks for the correction.

So far, I have only been able to get a wrench on one of the "right" injector connections - the forward cylinder. When I loosen it and crank the starter, I'm seeing no sign of fuel.

Also - it IS a NAPA filter, but the gasket does seem to be seated correctly, and not blocking the passages.

So given this - would your suspicion go to the shutoff valve in the injection pump?

Also - do you have any tips on getting to the fuel fittings on the injectors? I'm going to try to find, or make a stubby wrench & try that. Not a whole lot of room to get much travel.

Thanks for the help - you've already straightened me out quite a bit.

Steve

fixt · Jun 11, 2019

For the NAPA filters you've pretty much got to put the gasket into the housing before you seat the filter. Otherwise it rolls into the filter and its just a mess. Its kind of a pain to get them to stay in the housing while you seat the filter, but a touch of grease on them will help them to stick in place. Inspect it with a flashlight to make the gasket isn't rolled. Then seat the filter and run the bolt in with the other hand while holding it in place.

For the injector nuts, search Amazon for
Offset angled open end wrench set.
That's a 15 and 60 degree offset for weird places.

Dieseltech can confirm this or not, but it sounds like your metering valve is stuck. If it is nothing to do but unstick it or you'll never get any fuel out.

Dieseltech · Jun 11, 2019

I get injection pumps in often lately that after setting awhile without running, metering valve, and/or rotor plungers are stuck from setting. Stale fuel, water in fuel, and bio diesel are the common causes. Most work fine again after a complete tear down, cleaning, resealing and testing. Some pumps that have bio diesel have so much sticky buildup the governor weights won't even fall out of the weight cage when turned up side down..

Bob N.Y. · Jun 11, 2019

Did you bleed the injector pump itself before trying to bleed the injectors?

MF135 Diesel - Won't start after fuel gelling

Red135

New User

Dieseltech

Well-known Member

Red135

New User

fixt

Member

Dieseltech

Well-known Member

Bob N.Y.

Well-known Member

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