Trying to fix Volvo Penta 2001 that refuses to start

[nick.theboatman]

Evening All.

Going gently mad here.. been trying to fix this engine for 3 weeks and slowly imploding...

HISTORY

The engine is on a boat that has recently navigated at sea (Irish Channel etc) so has been running. The engine then failed when on inland water. The engine has been removed from the boat and is on the bench, no exhaust, no air filter. An electric fuel pump has been fitted upstream of the mechanical pump.

The big ends have not so much "gone" as disappeared;
the crank-to-camshaft timing was out by 3 teeth (27 degrees) retarded (previous owner?);
the injector was poor;
the piston damaged;
big end as above;
mechanical fuel pump not working properly;
head gasket had leak tracks;
possibility of a glazed bore.

NEW ITEMS

new injector (new copper washer, spray pattern good);
new mechanical fuel pump and some hoses;
new piston, rings; honed the bore with a bobbly honing tool in a drill;
head scraped (but not honed), new gasket and 600F mastic; no apparent leaks;
new valves and re-seated with coarse and fine compound and 2.5 micron cerium oxide paste;
new big end shells as above;

PROCEDURE

Its been apart don to the crankshaft, and back, 5 times now in the past 3 weeks
reassembled including trying 4 degrees advance on the crank-cam angle (note that when the 2 dimples on the cam line up with the one on the crank this gives 5 degrees after TDC);
straightened damaged and bent rack;
re-set the injector pump shims to correct height assuming 22 degrees BTDC injection point;
lots of new gaskets;
compression test but shows only 140psi

FINDING

Refuses to start including use of hot air gun and copious amounts of Easy Start;
the engine puffs white smoke, "pops" but not enough to get going.

Any ideas? I'm losing the will to live...

[nick.theboatman]

Forgot to add that we did bleed the system (properly) and have been running these tests with the front off the govenor and operating the rack by hand. There is no question that it is trying harder when the rack is at the 1/2 way point than "full" - at full we get lots of puffs of white smoke (and black smoke when we push in the Easy Start and get the hot air gun going) but "pops" when the rack is at 50%. But no starting. And she's also had a new starter motor and we are supplementing the bench battery with a 100A bench PSU
No slouch here...

[Wotname]

Originally Posted by nick.theboatman

compression test but shows only 140psi...

This seems extremely low to me.
While I'm not familiar with this engine, I would expect any diesel engine of this type to be above 300 psi.

[Wotname]

Have you tested the valve seating by seeing how long they will hold alcohol (methylated spirit) ?

Have you tested the ring / bore sealing by seeing how long diesel will seep pass the rings into the sump?

If so, how long in each case?

[Chief Brody]

Originally Posted by nick.theboatman

Evening All.

Going gently mad here.. been trying to fix this engine for 3 weeks and slowly imploding...

HISTORY

The engine is on a boat that has recently navigated at sea (Irish Channel etc) so has been running. The engine then failed when on inland water. The engine has been removed from the boat and is on the bench, no exhaust, no air filter. An electric fuel pump has been fitted upstream of the mechanical pump.

The big ends have not so much "gone" as disappeared;
the crank-to-camshaft timing was out by 3 teeth (27 degrees) retarded (previous owner?);
the injector was poor;
the piston damaged;
big end as above;
mechanical fuel pump not working properly;
head gasket had leak tracks;
possibility of a glazed bore.

NEW ITEMS

new injector (new copper washer, spray pattern good);
new mechanical fuel pump and some hoses;
new piston, rings; honed the bore with a bobbly honing tool in a drill;
head scraped (but not honed), new gasket and 600F mastic; no apparent leaks;
new valves and re-seated with coarse and fine compound and 2.5 micron cerium oxide paste;
new big end shells as above;

PROCEDURE

Its been apart don to the crankshaft, and back, 5 times now in the past 3 weeks
reassembled including trying 4 degrees advance on the crank-cam angle (note that when the 2 dimples on the cam line up with the one on the crank this gives 5 degrees after TDC);
straightened damaged and bent rack;
re-set the injector pump shims to correct height assuming 22 degrees BTDC injection point;
lots of new gaskets;
compression test but shows only 140psi

FINDING

Refuses to start including use of hot air gun and copious amounts of Easy Start;
the engine puffs white smoke, "pops" but not enough to get going.

Any ideas? I'm losing the will to live...

I can only comment from my early car driving days when I tried to repair engines myself. If that lump is a high miler, there maybe a chance that the bores have worn oval meaning original replacement pistons and rings will be useless...so you’re looking at a rebore + over sized pistons + over sized rings. Also, the head may need to be de-coked and skimmed seeing as you removed it from the block.

It may be a better option to exchange it for a recon unit, including the head. Don’t cut corners by thinking a short block will be all you need.

I may be wrong and I hope I am...but I feel your pain...I really do.

[jimbunyard]

Timing.

Forget the marks on the gears, time it based on #1 cylinder TDC compression stroke and figure the cam and injection pump settings from there...

[nick.theboatman]

Originally Posted by Wotname

This seems extremely low to me.
While I'm not familiar with this engine, I would expect any diesel engine of this type to be above 300 psi.

Absolutely - wll maybe 275... so where's it leaking?

[nick.theboatman]

Originally Posted by Wotname

Have you tested the valve seating by seeing how long they will hold alcohol (methylated spirit) ?

No but we did connect a 110psi air line to the compression tester adaptor. The pressure holds well and when you hit the valve tops with a hammer (dotn try this at home kids) the valves pop well.

Originally Posted by Wotname

Have you tested the ring / bore sealing by seeing how long diesel will seep pass the rings into the sump?

Also no - good idea

Originally Posted by Wotname

If so, how long in each case?

How long is "long"? bearing in mind that this is a new pot with new rings in a freshly honed bore...

[nick.theboatman]

Originally Posted by jimbunyard

Timing.

Forget the marks on the gears, time it based on #1 cylinder TDC compression stroke and figure the cam and injection pump settings from there...

Yes did that - in terms of drew up a timing diagram.
Remember that this is a 1-pot engine...
Exhaust valve is closing from 630 deg to 0 deg; opens from 510 to 585; stays open between 585 and 630;
Inlet valve opens from 0 to 90, stays open 90 to 135, closes between 135 and 225 (spec says 30deg > BDC #1);
Injection cam starts rising at approx 260, peaks at 380 and is back down by 450; manual says injection at 22 +/- 1 BTDC (#2) (ie 338). We are squirting at 338.

[nick.theboatman]

Originally Posted by Chief Brody

I can only comment from my early car driving days when I tried to repair engines myself.

You and me Diesels are pigs mind...

Originally Posted by Chief Brody

If that lump is a high miler

1990 at the latest...

Originally Posted by Chief Brody

there maybe a chance that the bores have worn oval meaning original replacement pistons and rings will be useless...so you’re loking at a rebore + over sized pistons + over sized rings.

Pot is pretty stiff in the bore (we did check the gap clearance with a ring and it looks ok ...)

Originally Posted by Chief Brody

Also, the head may need to be de-coked and skimmed seeing as you removed it from the block.

So the pro engineers I know say "lap the head if its been stripped". The others say "wang it down with "Hermetite Red, that'll fix it". We took the middle way by skimming with various sharp objects to get the crap off and skim the peaks of the milling marks... Been good in the past.

Originally Posted by Chief Brody

It may be a better option to exchange it for a recon unit, including the head. Don’t cut corners by thinking a short block will be all you need

He's spent more than £800 now - well past the point of no return :/

Originally Posted by Chief Brody

I may be wrong and I hope I am...but I feel your pain...I really do.

Thanks !!

[Wotname]

Originally Posted by nick.theboatman

..............

How long is "long"? bearing in mind that this is a new pot with new rings in a freshly honed bore...

Well it is only a rough and dirty test and I can't offer hard and fast numbers but 10 or 30 minutes is way too short but overnight is good.

[nick.theboatman]

Originally Posted by Wotname

Well it is only a rough and dirty test and I can't offer hard and fast numbers but 10 or 30 minutes is way too short but overnight is good.

Very interesting - thanks - good idea....

[Wotname]

Originally Posted by nick.theboatman

Absolutely - wll maybe 275... so where's it leaking?

I'm not being funny but there are only 5 ways that it can leak and you have to double (or triple) check each one.

1. valves
2. rings
3. head gasket/head/sleeve interface.
4. badly cracked head (unlikely)
5. injector (very unlikely)

IIRC, this is a sleeved engine. If so, was the sleeve removed and did the sleeve project evenly above the top of the block when refitted.

Or was the compression testing methodology was wrong???

[Wotname]

Originally Posted by Wotname

I'm not being funny but there are only 5 ways that it can leak and you have to double (or triple) check each one.

1. valves
2. rings
3. head gasket/head/sleeve interface.
4. badly cracked head (unlikely)
5. injector (very unlikely)

IIRC, this is a sleeved engine. If so, was the sleeve removed and did the sleeve project evenly above the top of the block when refitted.

Or was the compression testing methodology was wrong???

Opps, make that 6.

6. Bent rod; not that this causes leaks but it does lower compression.

[deblen]

VP 2000 series "cold start" proceedure maybe? https://forums.sailboatowners.com/th...-start.173628/