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doog · 06-10-2022, 17:31

My friend has a little Cacade with the Volvo MD2 which sadly got submerged, but they got it pumped out and changed the oil and then the fuel filters, and it is now fully bled and still refuses to start with fresh clean fuel.
I suspect the injectors are blocked because when it cranks there is not even a white puff of diesely smelling air. Id like to remove the injectors and clean and check them, and removal isnt hard but I see no details on how these little fuel injectors come apart.

Im going to do the test spray with WD40 into the intake and see if that makes it run, and Id appreciate any tips on how to tear down the injectors and inspect and clean them. (I broke down the Perkins injectors very easily and found its not hard at all to open and clean and inspect them, in spite of all the stern comments that they arent user servicable and it requires special tools. In the case of Perkins its just a large wrench!)

Thanks any Volvo guys!

doog · 06-10-2022, 17:47

https://marinedieselbasics.com/wp-co...1-Workshop.pdf

OK found this on P 22/23 and its very do-able. Im on it! Id still appreciate any help!

**skipperpete** · 06-10-2022, 19:02

I’m totally not a Volvo guy but I’m genuinely interested to know by what process you arrived at the conclusion that the ”injectors are blocked”
Following[emoji848]

doog · 06-10-2022, 21:18

Happy to explain, we crank the engine for quite some time and it was spinning with good compression and good speed and normally you would get little puffs of compressed Fuel and Vapor out the exhaust that smells like diesel. All we got was dry air and water from the water injection. The exhaust as we crank the engine did not even smell like diesel fuel even though I know that it was thoroughly bled clear through to the bleed off tubes and there was good pressure in the fuel system. So do you see that's why I'm assuming the injectors were blocked from contamination in the fuel. Anyway I'm proceeding with the WD-40 spray which should make the engine attempt to run as long as it's sprayed. Then from there will pull the injectors and see if I can clean them. I'm fully expecting to find some sort of particulate blocking the nozzles.

Ballsnall · 06-10-2022, 23:10

Quote:

Originally Posted by doog

I'm assuming the injectors were blocked from contamination in the fuel.

Hard to see how the fuel would be contaminated?
At a guess I would suggest the injectors are not getting any fuel. Have you bled right to the injectors or just to the pump?

doog · 06-10-2022, 23:26

"Fully bled" there were fuel issues.

**skipperpete** · 07-10-2022, 00:00

By “fully bled” do you mean you have fuel coming out of the the loosened injector pipe union at the injector?

Patrick of M · 07-10-2022, 01:25

+1 with skipperpete. Fuel needs to be bled to the injector supply union. Keep it simple.

doog · 07-10-2022, 09:31

Thanks to Skipperpete and Patrick of M for sharing how to bleed the fuel system, I think my post was clear that Im very experienced at bleeding a fuel system and dont care to rehash those fundamentals. And for anyone unclear the fact is that its the bleed off line for the return fuel that should show high-pressure and bubble free fuel so you know, as I DID, THOROUGHLY, and then you know the system is totally air free. And so if the engine then will not fire its either got insufficient compression or not getting fuel.
Im going to do a WD40 shot and see if it will chug when this gets into the cylinders and someone suggested the little shut-off button can get stuck. I dont think it is but possibly so. It could have experienced corrosion as a result of submersion. Perhaps a solid rap on that little mechanism, but again if the shut-off button were stuck I dont think I'd be seeing fuel pressure at the return lines.
No evidence of water in the fuel but it did have a funky contamination and were using clean, fresh fuel drawn from a new container just filled.

**skipperpete** · 07-10-2022, 14:47

Quote:

Originally Posted by doog

Thanks to Skipperpete and Patrick of M for sharing how to bleed the fuel system, I think my post was clear that Im very experienced at bleeding a fuel system and dont care to rehash those fundamentals. And for anyone unclear the fact is that its the bleed off line for the return fuel that should show high-pressure and bubble free fuel so you know, as I DID, THOROUGHLY, and then you know the system is totally air free. And so if the engine then will not fire its either got insufficient compression or not getting fuel.
Im going to do a WD40 shot and see if it will chug when this gets into the cylinders and someone suggested the little shut-off button can get stuck. I dont think it is but possibly so. It could have experienced corrosion as a result of submersion. Perhaps a solid rap on that little mechanism, but again if the shut-off button were stuck I dont think I'd be seeing fuel pressure at the return lines.
No evidence of water in the fuel but it did have a funky contamination and were using clean, fresh fuel drawn from a new container just filled.

No problem Doog, and thank you for sharing your knowledge, we all benefit from the information in your post.
Hope you get it running soon.

Searles · 07-10-2022, 22:00

Sounds to me like the governor is sticking,and as this is spring loaded on these motors you can still move the control lever with out opening the governor ,also when trying to start be sure that the throttle lever is wide open .⛵️⚓️

Patrick of M · 07-10-2022, 23:41

I know you say you have bied it thoroughly, but just looking at the return will not mean you have fuel all the way. I have a MD17 which is a similar engine, with air in the system(no "back pressure from the injection pump) the lift pump pushes fuel out the return line, because of how the return line connects into the system. The return fuel doesn't recirculate back to before the pre lift pump like in a (more modern?) system. I agree with others here that it is probably the governor inside the injection pump hanging up, you might using ether/whatever to get it chugging, it may vibrate itself into working .
Lot's of information online on opening/cleaning/testing these easy to remove and service injectors, and if you have the time no harm in doing that.
I'm always a little skeptical of diagnosis that looks at multiple components failing concurrently (all injectors in your case) but as you have only 2 it is somewhat possible. A single point of failure (sticky governor in injection pump, seems more likely). Anyhoo, try cracking the intake line open at the injectors, that'll let you know if fuel is being delivered from the injection pump.
(Usual Warning: Watch out you don't inject yourself with fuel !!!)

Ballsnall · 08-10-2022, 03:29

Quote:

Originally Posted by doog

And for anyone unclear the fact is that its the bleed off line for the return fuel that should show high-pressure and bubble free fuel

I'm a bit confused by this, I've never see high pressure fuel in a return line before?

Patrick of M · 08-10-2022, 05:06

Quote:

Originally Posted by Ballsnall

I'm a bit confused by this, I've never see high pressure fuel in a return line before?

It's no to high pressure, just enough pressure to fool you if the injection pump isn't delivering fuel. i.e. if you crack the return you can see fuel coming out of the return port (backwards really) but no fuel could be coming out of the injection pump .
This is on a MD17, it has a healthy pre pump, doesn't depend on the injection pump suction for fuel delivery to injection pump.(kind of like modern common rail, where an in tank low pressure pump delivers fuel to the HP pump which delivers HP fuel to the common rail).