Help - YANMAR 4JH2E engine only idles ?

[cruizn]

Originally Posted by GreenWave

Assuming this thing is in the water? What’s does the prop look like?

It has three fins & rotates moving the "thing" forwards when in the water.. but the thing is on hard standing ATM.

[cruizn]

Originally Posted by skipperpete

I’m assuming that the fuel system from the tank to the injector pump is all ok and the problem is the injector pump.

I'll check the solanoid this afternoon.. I really appreciate your response as this could we be the problem.. let's see

[GreenWave]

Originally Posted by cruizn

It has three fins & rotates moving the "thing" forwards when in the water.. but the thing is on hard standing ATM.

Fair enough. 😀

[skipperpete]

Yes, I agree the ability to operate the engine shutdown solenoid manually with a red pull fitting does indeed make it an emergency shutdown if the keyswitch or stop button fails but avoid at all costs trying to use it to stop a runaway engine, it’s not safe being too close to an overspeed .......and trying to unstick a stuck rack or plunger using the stop control rarely works, the soon to be detached governor weights would be trying very hard to do that already with zero success.

[mlydon]

You should change all filters first thing, and check your lift pump for proper operation
Matt

[cruizn]

I've pulled the injectors out after trying the obvious.. new fuel / filters etc.. filter looked fine & fuel looks clean. Time to have injectors cleaned. Will have them sonically cleaned.
They look to be blocked.. loads of carbon build up. I'll post an image once I get home.

[ScottRhodes13]

I had a similar problem on my 4jh2-hte. It turned out one of the injector lines was slightly loose where it connected to the injector pump. It wasn't the nut on the fuel line that was loose, but a larger nut, that the fuel line taps into. You have to check it carefully because, with the fuel line snugged up, the larger nut can feel tight, even when it's not.

[cruizn]

A local diesel company tested the injectors & has confirmed all four injectors are blocked really badly.

They said they'll require 4 new nozzles.

note: I feel even once the injectors are replaced I may still need to disassemble and clean out the governer. Now that'll be a scary job considering engine access is terrible on this boat

[skipperpete]

I’m looking forward to seeing your pics of the coked up nozzles. Pulling the governor apart to “clean it out” sounds a bit optimistic, which injector pump of the 3 types fitted to the 4JH2 series do you have on your engine? Maybe post a pic of that too. The usual practice is to remove the injector pump from the engine to get it serviced or adjusted by a pump tech, probably the guy who is doing your injectors but before you do that, it’s important to establish that the problem actually does lie within the injector pump ......and there is a different method to prove or reject the proposition that the governor is faulty for each pump.

[cruizn]

Image of the blocked Injectors

[cruizn]

Photo I took of my yacht ( Steel 92 Van De Stadt ) that's been on the hard standing for the past three years that I hope to finally drop into the water once the engine sparks up again

[skipperpete]

They don’t look terrific, take care of those Teflon heat shrouds,they look pretty good and might be reusable. The sealing washers are definitely ok to re use and if you need any parts for your engine since you’re in Sydney contact Minards, we’ve been dealing with them for everything Yanmar since Richard Minard owned the business. 🤢that looks like my thumb in the photo.
The state of those injectors is unlikely to be the cause of the engine failing to get above idle ( and now not starting at all) so I’ll be interested to hear if new nozzles has any effect.
Since your boat is on the hardstand it’s unlikely that there’s a risk of flooding the exhaust from overcranking but if your hooked up to a bucket it can still happen.

[cruizn]

Yes I agree.. as the mechanic has mentioned it will most probably be an issue with the governor.... fingers crossed

BTW.. slightly off topic but worth mentioning is the fact after this engine is running I then have a YAnmar/ Kohler gen-set to contend with... uugh !
I just a had thought... being that both are Yanmar, maybe I could have pulled the injectors from the genset but it is only 3 cyl. or maybe not

[skipperpete]

Generator looks good but the mixer elbow looks dodgy and the 180° kink in the fuel line can’t be good. . No on the injector swap, the genset is a 3TNE (3YM30) engine.

So if I was the guy attending the call out for the 4JH2 TE original problem, this is what I’d do next ( assuming the injector pump is the inline type).
First I’d do all the usual checks, lube oil level, coolant level , gear oil , check that the turbo shaft can be spun fairly easily at the compressor side, and, since the injectors are already out I’d do the ultra quick cylinder leakage test just to make sure the head gasket isn’t badly blown between 2 cylinders ( unlikely because it did initially idle reasonably well). Then I’d establish that the injector pump is getting a good flow of clean bubble free fuel with a section of clear fuel hose , check the stop control operation and the position of the cold start lever and cold crank the engine to observe the fuel flow through the delivery valves.... if there are constant spurts from ALL hp delivery valves, pull the stop control and see if the injection spurts stop completely.... this is important because I need to know the stop lever will actually cut off the fuel if the governor fails to pull the rack back to idle and goes into overspeed when the injectors and pipes are refitted
After the newly serviced injectors are in and connected I’d crank the engine until fuel appeared at the loosened injector union , tighten the nuts and try for a start with the cable off the speed control lever. Under normal circumstances the engine should start and respond to the speed control lever ( re establish water supply to seawater pump)
If the engine just idles, stop, reprime and try again. If still no response move to next check.
So here’s where it gets tricky and I’m not suggesting you try this, it’s just what I’d do . I’d take the side plate off the injector pump and operate the fuel control rack manually to feel the response of the governor. Normally the rpm will increase and the governor will forcefully pull the rack back to idle. If it fails to do so or fails to increase in Rpm and the fuel supply is as originally verified I’d now remove the injector pump ( using the Yanmar gear puller that I brought with me to the job) and take it to the pump technician to be investigated.
This information re the rack is useless if you have the Bosch VE pump..... but the same gear puller fits.

[Icarus]

Fuel injection pump and governor issue.