Volvo EC15B mini - engine removal & injection pump overhaul - plus ......

[jackpreacher]

Temperature Sensor Testing

Tuesday 4th December

1. Tested the temperature sensor - as the engine ran I short circuited the wire to ground and the engine stop solenoid activated. All fine there. Tested around a dozen times.

2. Doug was running lumpily so I removed all 3 injectors and serviced them, again. One of the injectors hadn't been firing as it was sooty. It turns out that when I had reassembled the injectors a few weeks ago I had put the fuel spill washer back in incorrectly. Engine fired up smoothly.

3. Did some work with Doug. He didn't cut out at all.

4. I did manage to stall the engine four or five times though, even when thoroughly warmed up, mainly when grading with the dozer blade when the gravel got sticky and heavy. I assume that Doug should just physically stop if he can't pull any harder as opposed to just stalling. He seemed to work more reliably on around 25% revs ( 25% refers to the throttle position).

Some work to do there then, but this is where I need the voices of experience to chip in

I took loads of photos which will be edited and uploaded in the morning.

On the whole I can at least work with my EC15, albeit a little sluggishly.

[jackpreacher]

Testing the Temperature Sensor

1. To test the temperature sensor the engine was started then the wire pulled away from the spade connector and held to ground against the valve cover body.
Temperature sensor grounding wire.jpg

2. The engine stop activated with a positive 'click' and the engine cut-out. This test was repeated successfully a dozen times.
Stop Solenoid.jpg

If you can't hear the solenoid being activated, or in fact 'released' then either the temperature sensor (or wiring)the is goosed or it's CPU controller which is under the seat.
This STOP solenoid is the type whereby it is safe or 'closed' (stopping the fuel supply) when there is isn't 12V supplied to it.

[jackpreacher]

Servicing the fuel injectors

Here is my procedure for removing and servicing the fuel injectors.


1. Remove the Fat air pipe:
Remove Fat Air Pipe.jpg

2. Clamp the fuel hoses that connect to the Fuel Injection Pump:
Clamp Fuel pipes to IP.jpg

Pull the overflow hose away from the IP. That is the top hose. The bottom hose, which comes from the fuel filter, can remain in situ but it's worth clamping as it prevents excessive amounts of fuel spilling through the overflow hose fitting on the IP.

3. Undo fuel injector pipes starting with the one on the right as this allows easier access to the subsequent pipes:
Undo Fuel injection pipes.jpg

4...and remove pipes:
And remove pipes.jpg

5. Release and remove overspill manifold nuts (or whatever it's real name is)
release fuel overspill pipe manifold nuts.jpg

..and don't drop the nuts in the engine bay (....guess who did that..)..
don't lose them or drop them in the engine bay.jpg

6. ...and pull away the manifold (careful not to bend the pipes):
pull away overspill manifold.jpg

7. Undo the injectors:
undo Injector .jpg

...and remove. Be careful of the copper washer which may remain in the injector port. A free Xmas Chicken to anyone who can guess WHO reassembled everything but left 2 of the washers on the workbench

remove injector.jpg

beware of stuck copper washer in injector port.jpg

8. SERVICING THE INJECTOR ( my cheap way)

Clean the injectors externals with petrol/white spirit:
Clean the externals of the injector.jpg


9. Loosen the Injector's main components by holding it in a vice:
Hold Injector in a vice to disassemble.jpg

10. Carefully disassemble the injector bodies - the top half (injection pipe inlet) screws into the bottom half (nozzle end)
Unscrew Injector.jpg

11. The injector components all need to be thoroughly cleaned. Here they are laid out in order of disassembly:
Injector Components.jpg

12. Check for obstructions from soot build up:
Clearview through the injector main components.jpg

13. Thoroughly clean the end of the spear/nozzle component. The pointy end is right in the injector port giving the fuel spray pattern:
Clean Injector spear.jpg

Reassembly is the reverse.

[jackpreacher]

Onto the Hydraulics

Wednesday Afternoon

1. Warmed up engine and hydraulic fluid for 20mins.
2. Removed battery compartment door then lifted the floor out.
3. Attached hi-pressure gauge to P1 (labelled from the manual)
4. Tested the pressure from the Hydraulic Pump - 85 Bar. The service manual states it should be 170 Bar give or take 5 Bar.

So, the reason that Doug doesn't travel too well is because his pressure relief valve is set way too low at around half of what it should be. At least now I know

5. Adjusted the PRV (engine running but no services) and tested the pressure. The maximum I could get Doug to hold revs against was 100 Bar, after that he just dropped revs, blew smelly blue fumes out of his exhaust and then stalled.

In the 3 or 4 seconds he worked at 100 Bar he stopped shuffling and actually turned on the spot
I reset him to 80 Bar so at least I can carry on doing the drive (1/3 mile long) grading without stalling all the time.

Now I need help from you guys

Is his engine goosed?

[Muz]

Not neccesarily .. Injectors are not just so simple to service though .. the working pressures are critical, and good though your intentions may have been, you may not have cured a fault within. They need tested on a jig to ensure correct operation.

For example .. I took one out of a single cylinder diesel cement mixer recently that I could see had completely the wrong spray pattern, I connected it up out side the cylinder and was spraying neat diesel and not atomising the fuel properly, and this engine would barely run... replacing it cured the problem completely and the engine ran fine. I stripped the faulty injector and could not see anything with the naked eye that convinced me there was a fault. Its possible, if you have eliminated all the other issues, that this is why the engine will not generate full power

If it is generating full power, it will generate near 200 Bar and at full relief, should not kill the engine, just make it labour only and smoke a bit.

Glad youve identified your main reliefs though .. thats a good job well done

Also .. shorting your sender wire to chassis just proves the ECU is doing its job .. it doesnt mean that the thermistor is not faulty, or there is not still a broken wire at the ECU, because together, these could still be giving a 'phantom' shut down

[jackpreacher]

That makes a lot of sense as the engine was generating full power (admittedly on 85 Bar ) before all the problems with the fuel injection pump. So maybe my tinkering has actually created a problem.

Tomorrow I'll rig up some kind of jig to observe the spray pattern from the injectors. I reckon one was a bit dodgy hence the sooted up injector.

Muz, do you calibrate/mend your own injectors or do you farm that job out?

[jackpreacher]

....and, er,.....one lump or two?

[Muz]

That makes a lot of sense as the engine was generating full power (admittedly on 85 Bar ) before all the problems with the fuel injection pump. So maybe my tinkering has actually created a problem.

No I think you've eliminated a steady stream of faults from someones discarded EC15 .. like many machines, theres a limit to what faults they tolerate before giving poorer performance .. The EC15 isnt the most refined piece of engineering, but being fairly basic its fairly easy to get to being what 100% it should be which is why I like them.

Tomorrow I'll rig up some kind of jig to observe the spray pattern from the injectors. I reckon one was a bit dodgy hence the sooted up injector.

You could try that but it wont always reveal a problem .. incomplete combustion could just as easily be low compression causing that .. (but if you forgot your copper washers at the injector seat that would give you some leakage )

but what ever you do and I cant stress this enough ... make sure you wear eye protection and keep your hands clear from high pressure diesel workings I'm sure you will know this, but as a public forum I have to remind folks

Muz, do you calibrate/mend your own injectors

No .. its a specialised job, that requires special test kit to measure pressure, spill, etc etc

[jackpreacher]

but what ever you do and I cant stress this enough ... make sure you wear eye protection and keep your hands clear from high pressure diesel workings I'm sure you will know this, but as a public forum I have to remind folks

Top advice.

1. Ok, so a compression test first - at least I can do that.

2. Injector spray test and pressure test - I'll see what I can rig up if the compression test passes muster. I sense the parting of money..........

3. I'll post photos of the PRV and test points for the hydraulic testing.

Oddly enough my new £89.00 service manual didn't have my injectors detailed. I wonder if the spill washers are the right way round

TBC

[Muz]

Oddly enough my new £89.00 service manual

Blimey has it got an 18 Ct gold binder

I wonder if the spill washers are the right way round

It wont matter .. all of that is on the low pressure side ... at worst you get a leak (if at all) .. but wont affect engine performance

[jackpreacher]

Blimey has it got an 18 Ct gold binder

Yeah, I know what you mean, plus it's a hard copy which means it'll be tricky to share with other EC15 owners. On the plus side the hydraulic schematics are first class, well, they must be because even I figured out where the PRV is located.

[Muz]

Yeah, I know what you mean, plus it's a hard copy which means it'll be tricky to share with other EC15 owners. On the plus side the hydraulic schematics are first class, well, they must be because even I figured out where the PRV is located.

Ahhhh........ you have a head start on many .. scratch that .......most other EC15 owners then even me .. from the shit I get from my dealers .. but there are 3 tho .. so still 2 to go

[jackpreacher]

Naturally I started with the easiest one to find...., and got lucky!

The pilot lines will be for another day

I actually like my EC15....we're both simple (I meant..er.....me & Doug...)

[Muz]

Naturally I started with the easiest one to find...., and got lucky!

The pilot lines will be for another day

You never need them .. just stick to the three main reliefs designated P1 P2 P3 on their .. erm .. maps .. no .. drawings .. umm sheets thingies

[jackpreacher]

You never need them .. just stick to the three main reliefs designated P1 P2 P3 on their .. erm .. maps .. no .. drawings .. umm sheets thingies

Visual aids....?? (Can one say that these days.....)

Once again I have thank you for advice which saves time and (probably) money.