Hello, looking for diagnostic process advice for the following problem: I have a Volvo ECR38 excavator that is fitted with a Yanmar 3-cylinder 27hp engine -- fairly common in various tractors and smaller machines, I believe. The machine is very hard to start. Always has been since I have owned it. Several service techs and other people I know who are knowledgeable about diesel engines have looked at it over the years without identifying a cause. So whatever is going on with it probably isn't super-obvious. Things like injectors working and glow plugs functioning have been checked. The symptoms are very consistent: engine cranks freely but doesn't catch. After many attempts to start it will finally burst into life and run at idle smoothly to temp. Sometimes it can take an hour to get it to start (not an hour of continuous cranking obviously). Sometimes it seems to help to just walk away, make a cup of coffee, go back to it and it'll start quite quickly. Once it has started and run for a while, it will subsequently start up immediately no problem for the remainder of the day. Next morning: back to hard to start. The syndrome doesn't seem to be correlated with ambient temperature. It's still hard to start on a very hot day. Initially this excavator was my only machine and I assumed this must be the way with diesel engines. However over the years I acquired a track loader and a large chipper and realized they start straight up even when cold. So clearly something is not right with the excavator engine. I'm looking for recommendations on how to diagnose the issue systematically. I've read that slow cranking might be the cause. Problem is I don't know how fast this engine is supposed to crank. It sounds slower than my 4-cylinder machines but not super-slow. That said, if slow cranking were the cause why does it start up just fine after the initial tussle to get it started at the beginning of the day? I've also read that air can be sucked into the fuel pump -- would that fault be consistent with the symptoms? Thanks in advance for any suggestions.
I'd start with a compression test. If this engine has a mechanical injection pump with a cold start advance it'd be worth checking that it functions as well.
When u turn the key to the “on” position but don’t start it, can u hear or feel the supply pump running..?? It should have an electric supply pump that pulls fuel from the tank and sends it up to the injection pump.. It’s easy to check.. And even if it is running, there’s no guarantee that it’s moving fuel.. in which case I’d pull the line off of it to SEE if it’s moving fuel..let it run into a clean white bucket for a minute..
Yes, the pump runs. It's been a while but I think we already checked that fuel is actually circulating. I can check that again to be sure. Also I've tried waiting in the "pump on" ignition state for a long time on the theory that fuel has drained back into the tank (someone gave me the idea that this was a possible failure mode at some point). It doesn't seem to matter how long you let the pump run -- it's just as unlikely to start regardless. One extra piece of data I didn't mention above that now seems perhaps more relevant is that there seems to come a point (after lots of cranking) where you can smell fuel in the exhaust. Typically the engine will fire sometime soon after (sometimes not, but often yes). This makes me wonder if there is no fuel reaching the injectors initially.
Hmm, interesting. The engine does not have particularly high hours so I hadn't considered compression but I will set to figuring out the injector thread size...
My Takeuchi with similar 3cyl yanmar engine had similar symptoms a while back. It turned out that my injector pump was weak causing long crank times to start. I believe what I did was pull all three injectors, and hooked them up to the fuel lines so I could observe the spray while cranking. I found one had weak spray pattern. Just the one weak output line on the injector pump was causing the problem. I bought a new Yanmar injector pump and installed it, not it starts at the touch of the key. Hot or cold. Have they verified all three lines coming out of the IP are giving the injectors enough pressure to make a clean spray pattern?
What happens when you turn the key to the left and give the engine heat even during the summer? My little Takeuchi TB016 always likes a bit of heat to start, even when it's hot out. I've had it looked at by service mechanics and had injectors serviced and they seem to think for the age of the machine, and small engine that it's sort of normal to add heat. In any event, the engine runs fine and starts. The other Takeuchi machines I have never need heat, even in the winter.
That’s kinda what I was thinking too.. Especially when u have a question about the starter speed.. The speed is there to get the pistons up and down quickly to create heat in the cylinders for combustion.. between the heat in the cylinders and the atomized fuel, that’s what starts/runs the engine.. So make sure the fuel is at the inj pump inlet and the glow plugs have 12v to the rail when u turn the key to the left AND they are working..& the starter is working good..
Seems to be the case in the Perkins (404) in our ASV 50. Needs 5-10 seconds of glow plug…even in summer. The Deere 4045 in our larger wheeled skid loader starts up perfect even down to -8c with no glow plugs. I do prefer this engine…
Seems certain engines develop a certain attitude, kinda like my women. Some like date in a can, some like heat, current wife requires nothing. lol My Kubota in my skid gets glow plugs even when it’s a 100 degrees out or doesn’t wanna get dirty. The Kubota in my Kubota starts clean, every time.
This sounds like the injector/s are not atomizing the fuel. Have they been removed and checked for pop off pressure and atomization?
Had basically the same engine in a older Kobelco mini had the injection pump rebuilt cause it was leaking and the checked the injectors myself as I was a heavy equipment mechanic and they tested fine. Couldn't get it started finally bought a set of aftermarket injectors and installed them it turned over about 5 times and was running still don't know why or how.
To help figure out if it is a compression problem without a gauge set up, you could try blowing out the air filter housing to make clean. Pull out the filters and while someone else is cranking it over spray 2 full cans of WD40 at the same time for maybe 10 seconds into the intake. Diesel engines love more oil on the compression rings for start up. If that works then maybe the injection is lazy like Vetech63 was alluding to or the compression problem needs more looking into. If you need to use only occasionally the 2 can WD40 compression boost may be a simple just get it going trick for the day or till you have more money to proper repair. Dont forget to put filters back in.! Worth a shot. Simon C
Hello, circling back on this one after finally finding a mechanic to take a look at it. He took a look at various things, diagnosed an ohmic contact on the glow plug wiring which he fixed. Declared it fixed since he could start it straight up. Ok, so then the next day I tried to start it. Wouldn't start. He returned, investigated further and diagnosed weak fuel spray from injectors. Said he'd haul it to his shop for further diagnosis. We had a bit of a discussion about how the injector pump is mechanical and perhaps the weak pressure is due to slow cranking. He mentioned that when he started it previously, the battery had been running flat due to constant cranking during diagnosis, and therefore he had hooked it up to his truck to get a good starting current. In the days since my brain has been crunching and last night I had an idea: let's try hooking up my big charger/starter unit to the battery and see what happens. This is one of those heavy units with wheels. I drag it out to the yard and hook it up to the excavator battery. Let it charge for a few minutes then set it to the start mode -- it reads 80A. Run the glow plugs for 45 seconds then turn the key and boom! It starts straight up. Didn't even crank once -- just ran. And it's a cold day. So...what does this tell us? Does it mean the injector pump is bad, since it should be able to supply fuel correctly to the cylinders with a less than perfect battery? Or does it mean the battery is deficient and the injector pump/injectors/starter are all fine? For reference the battery in it was new when I got the machine in 2019, so now getting a bit old, but then again it never started easily. In fact I replaced the battery because it was hard to start. I can't get a clear read on what battery specifications should be. The manual says 65Ah with no CCA spec and no size. It says part ba3101 but the internet knows nothing about that. Online sources searching on the machine type say 850 CCA. The battery I have in it is a 800CCA/50Ah group 34/28 Optima Red Top which I think is the thing the parts store sold me when I took the original battery in looking for a replacement. This seems to be an AGM battery which on reflection might not be the best option for this application. Also there seems to be room the battery compartment for a somewhat larger battery. Also a bit embarrassing since I am officially an electrical engineer therefore in theory should understand batteries...
Just buy the largest quality commercial lead acid battery that you can find that will fit into the hole, secured down. Hook a meter to it to see how far it goes down when someone else is cranking it. If it being new goes below about 10 volts after 5 seconds, best check with clamp on in case the starter is dragging and grounding out. If it goes fine every time, you know all about batteries. I don't get into these fancy batteries, I like what works at minus 30C. Simon C
What type of injection pump is on this engine, the old inline pump or the newer rotary pump? Can you take a pic of the pump?
My Takeuchi TB260 starts very easily but the battery in it would be weak after about 3 days and need charging to start. I installed a group 31 with 1000 cca but to do so I had to remove one of the stops to lengthen the battery compartment. I now have no start issues regardless of how long it sits idle. Peace of mind is a good thing. Moral of this story is that more is much better any time a battery is the topic.
I have all the above symptoms on my Tak 23R. At nearly 4000 hours,I’ve decided the engine is simply wore out as it burns oil and takes half an hour to warm up. I’ve tried all the basics and got nowhere. Some days it starts,other days it doesn’t.Weather and ambient temperatures make no difference. Either makes no difference. It gets serviced at the 250 hour mark,but I’ve poked new fuel filters as a precaution prior to that as it gets filled from drums. One point I’ll make is that I took my eye off the ball with the air filters.They need checking any time it’s been in dusty conditions as they were filthy.I’ve since replaced them with new and noticed there doesn’t appear to be any good seal on the housing cap.I suspect it’s been sucking in dust for many years more than the filters can cope with. The engine oil was also extremely dirty and black before it was due a service. Too late for the engine,but it does work pretty well once it gets going. Anyway,I’ve given it a complete service again and stuffed an old D8 o’ring in the air filters lid.It seals nicely now. I’ve also put it into a shed for winter and use a heater to warm the space up before starting. It now starts consistently after a couple of attempts. We’ll see how long it lasts. To be honest,I quite enjoy the battle to get the little sod fired up,it reminds me of the days of wrestling with the big D8 and D9 pony motors
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That space heater soon gets that engine block too hot to touch and I’m thinking it’s definitely helping with a faster,easier crank.Blowing hot air straight into the air intake with a torch didn’t have the same effect I thought it would and either has zero effect surprisingly. At the end of the day,I’ve not owned it from new and these machines rarely get the maintenance they need,so I’ll take whatever I can get out of this and will be happy to replace the engine when the time comes,if ever. It’s probably made its money back for me over the 2 years or more I’ve had it and has become a firm favourite in my yard.
Does look to be an abnormal amount of soot out the tailpipe. Too bad about the possible dust intrusion, but sounds as if the digger has done you well! Looks to be in nice shape, and a real handy size...
I bought a TB135 United Rental unit. The caps three clips had broken some of the plastic filter housing off where they clip on, and the air filter cap was hard to stay on or tight. As you said, dust had been getting into the engine. The 3 clip cap is always something to check. Otherwise, Takeuchi's are good machines. I replaced my TB135 with a new TB240.
Very nice to have a new Tak
My 50d was having issues starting, mostly when it got colder out. I ended up getting new batt cables made, and it cured it.
Same with our 50d. I had some lugs crimped onto heavy welding cable for both positive & negative; now starts right up. Found internal corrosion at low points in cable; externally it looked perfect...