Yanmar loses power, slows down & kills

[tallyho8]

I know that this is WAY off in left field. But.....
Some yanmars, run their regurn fuel into a collection bowl (for cold starting), then back into the tank. What would happen if that return line was somehow partially clogged? On startup, the line would have no pressure, but after running for a bit, it would fill up and there wouldn't be any room for the return to go. But, if that was the case, I guess there would be lots of black smoke from unburned fuel. On second thought, nevermind - wasn't a good idea after all.

This has been mentioned and in post #19 I took off the return lines and no fuel came out. I was wondering if much fuel was supposed to come out while the engine was running.

I really thank all of you for the suggestions as I am now clueless as to what my next step will be. I guess I need to remove the injectors and find a place to test them. But since they work perfect when cold I don't know if defective cold injectors will test bad.

 

[chriswheeler]

Last think I can think of is remove some of the engine oil and see if there is some diesel in it. If you smell diesel in the oil you may have lost a o ring in the fuel pump, when the engine heats up, diesel that should go to the injectors could be passing into the crankcase. My money would be on an injector. Did have a fuel pump fail like this on a larger Cat engine ( 35V12 ) when the injector return fuel line was plugged. Sounds like you have a clear return line. Just a note, both of my Yanmars ( 3t84 and 3t90 ) have very little fuel returning from that line. Last summer I replaced both of the little thermostart tanks and it took more than 4 hours of hard running to fill either. One further note, if it does smell like diesel in the oil, do not run the engine until repaired. Running this way will wipe it out the bearings. Good luck,
Chris

 

[kenmac]

tally, Just an idea. replace all of your fuel lines . this would be a cheap fix if it turnes out to be bad fuel lines. Worth a try & not expensive. I have replaced all of my original fuel lines

 

[YanmarFever]

I have an FX235-D that did the same thing, about every 10-20 minutes it would bog down.

I traced it to a rusty fuel tank, yes a rusty tank. I would clean out the fuel lines & filter and it would run great for another 15 mins. 15 minutes is how long it would take to clog up the fuel line again, and again ect... I must of spent 12 hrs cleaning, changing, fussing and head scratching trying to figure this one out

I replaced the tank, and all my troubles went away.

If you go that route, I have an extra tank from a YM1702-D here on the shelf
check your tank really good with a flashlight while its EMPTY first.

 

[Underwaterdog]

TractorErnie just jogged my memory. Many years ago I had a neighbor with a JD gas burner that was doing the same thing. The fuel would just quit running out of the tank. Turned out that it was a little round piece of pee gravel that was finding its way to the line in the tank, and stopping the flow.. Many tanks are set up so that the fuel pick up is about a 1/4" above the bottom of the tank to prevent picking up debris, so this may not be the case just an idea. If it is definitely not a fuel delivery problem and you have ruled out any type of engine issue, I'm thinking it is a injector or something in the pump. It may not be as hard as you think to find someone that can work on it. I did a Google on diesel injector service near Katrinaville and found this: Jefferson Diesel Specialist, Inc. Harvey, Louisiana It says they work on all makes and brands.

 

[tallyho8]

Thanks for your suggestions about the fuel lines and tank. I have replaced the lines and as I said earlier, I put a fuel can on the hood and ran a line straight from it to the injector pump, bypassing the fuel tank, filters, lines, and it still did the same thing.

I will be seeking professional help in the morning. (for me and the tractor)

 

[Underwaterdog]

If you find a good psychiatrist in the NO area.....and I mean a good one, please PM me. I have had more luck finding good diesel mechanics.

 

[YanmarFever]

Hey Tally, does the 1802 and the 1610 use the same injectors ?

I have a bummed 1610 engine in a container

 

[YanmarFever]

Tally,
Have you by any chance replaced ALL the rubber fuel lines ?

Missing any copper washers from the banjo fittings to the injector pump?

checked all the injectors for proper spray and that they are tight?

Pulled the side door open on the injector pump & check that all looks ok while you move the throtle handle back & forth.

finally, have you WAVED your magic japanese keychain we sent you over the engine, while burning incense and rocking out with Hendrix over the speakers?

 

[tallyho8]

Hey Tally, does the 1802 and the 1610 use the same injectors ? I have a bummed 1610 engine in a container

I don't know, but I am going to take my injectors to a shop to get them tested tomorrow. I don't know which shop yet, but.........