Volvo Penta D1-20 Fuel Issue

[mjmcpo]

I just returned to my boat which has been laid up in the Dominican Republic for about 8 months. I only have basic diesel engine knowledge. Engine was hydro locked due to diesel bug. Guessing an injector was leaking and it grew while I was away. Anyway, pulled injectors to clear things out and then had the injectors checked at a specialty shop. Injectors back in, but now no fuel is getting to them. Have tried bleeding air out by cracking one of the injectors (and all 3), but no luck. New pre and primary filters just changed. Good clean fuel is getting to the primary filter and coming out of the bleeder screw at the hand pump, but not getting any fuel to the injectors. Any thoughts? Having trouble finding a mechanic here and trying to catch a weather window in one week so the pressure is on.

[skipperpete]

It’s quite rare to see an engine hydrolocked by diesel fuel so I’m not going to follow that suggestion, but what is likely is that the injector pump has a stuck plunger, this is quite common on your engine type and invariably means taking the pump to your local fuel injection tech. First off you need to be absolutely certain that the pump is jammed by removing the 3 injector pipes from the delivery valves and spinning the engine over....... assuming you have a good flow of bubble free fuel at the bleed points and the stop control in the “run” position there should be fuel appearing at the 3 delivery valve holders. If all 3 are popping out a bit of fuel as the engine cranks, pull the stop lever and repeat the cranking, no fuel should be now be coming out of the delivery valves. If this is the case, refit the injector lines and leave the injector nut loose then crank until little spurts of fuel are seen at that joint......tighten the top connections and try for a start ( maybe do a preheat too).
Before doing any of the above, turn off the raw water intake to avoid the far more common seawater hydrolock.
If the previous procedure shows no hp fuel the most likely cause is a seized plunger in the injector pump.

[mjmcpo]

Thanks for the thoughtful reply. I’ll try your suggestions tomorrow when I get back to the boat. Still on the hard btw. Just trying to make sure it will run when I splash. Four years of ownership and the engine has always been reliable. Only around 400 hours on it!
When I got back here three weeks ago it wouldn’t turn over by hand. When I removed the injectors it turned over easily, but some sludge was ejected.. Really hoping it isn’t a bigger issue.

[skipperpete]

That sounds a bit ominous, but it’s encouraging that it actually turns over. Check the level in the coolant tank, it’s not unheard of for the heat exchanger to fail through to the exhaust section, usually at the mixer elbow joint, if it’s coolant in the cylinder you have a good chance of it surviving..... seawater, not so much.
That black liquid is very unusual , is it oil or water based? Your engine is unusual in that it’s possible to flood the cylinders with engine oil if the rockerbox gasket is broken, there’s only a thin gasket between the upward facing intake ports and the valve train area. I’m very interested to hear how this black goo appeared in all three cylinders.

[mjmcpo]

About the sludge that came out of the cylinders, I’m operating on the assumption that it’s diesel bug 🤞. I will update as things progress.

[mjmcpo]

We ended up pulling the engine to taker a deep dive. Ominous was right! It was an utter mess inside. Among other things, there was significant corrosion in the cooling side with holes eaten through. It’s since been completely disassembled and I’ve ordered an overhaul kit with new pistons, rings, bearings, new stainless exhaust elbow and oil pump. Cylinders look ok. Hoping to have it back up and running soon after all parts arrive.

[skipperpete]

It’s a sad sight to see, the coolant entering when the heat exchanger finally corroded through might be the reason the cylinders aren’t ruined. I suspect that your mixer elbow has been the enemy for quite a while, that degree of wastage didn’t happen quickly and it’s the reason I keep pointing out ad nauseum that if you ever see a line of corrosion at the joint between the mixer and the exhaust manifold there is a need to remove the mixer elbow and investigate. There is NO circumstance where seawater can be present and justified at that joint. It might be from a failed mixer elbow, a faulty siphon break, an Aqualock that’s too small to retain all the drainback from the exhaust hose or a badly designed exhaust with too much back pressure, either way, that joint should never see water on Yanmars or those small Volvo’s.
Ford Lehman’s, Solè engines, and some westerbekes however do have coolant in this location sealed in by a gasket so it’s not ALWAYS a cause for concern but the MD2030/2040’s , the D1 and D2 Volvo’s and the 3&4JH Yanmars are definitely a worry.