volvo penta powerless

[Fatmobile]

Great that you could get a leakdown test done.
Does this engine have mechanical lifters? If so; maybe it's been awhile since they were adjusted.
Clear lines between the injectors can tell if one of them is microchanneling/pissing.
Otherwise is there a place you can have them tested/rebuilt?

I keep thinking the injection pump must have been run dry, to seize up like that.
A question about the fuel supply.: Do the engines share any of the filters? Just one tank for both injection pumps?

[TylerDurden]

IPs can't run dry on a running engine... the engine will stop if the level drops an inch or so.

IPs can get hot and sieze, if the out flow is restricted.

[reimatic]

flow restriction...
that can be confirmed with the defect injectors
i do not know what was wrong with those, but after i got them back from bosch workshow engine got even worse preformance.

now mounted brand new injectors and engine does max 3200rpm i gear.

takes longer time to get up to this rpm compared to engine nr2

so still something wrong with this.
my mechanic say that the inlet valves leaking could be causing this. but he gives no guarantee for this because the nr2 engine inletvalves leak as well.
question is why there is no soot in the intercooler or inlet mainfold???

i am preparing myself for cylinder head removal.
and i can not figure out anything else to check anymore

[Fatmobile]

Valve clearance adjustment mechanical or hydrolic?

[reimatic]

Mechanical

Valve clearance adjustment mechanical or hydrolic?

[TylerDurden]

flow restriction...
that can be confirmed with the defect injectors

Not really... the total fuel flow through the pump is much greater than the fuel to the injectors. Total flow is about .5l/min at 1000rpm.

The large flow cools the pump and goes back to the tank.

What is the compression reading on each cylinder?

[reimatic]

27bar

[TylerDurden]

Hard to believe valves are leaking with 27bar compression, but maybe the volvo specification is much higher?

It sounds like bad camshaft timing. This is as critical as IP timing.

[reimatic]

Volvo workshop manual says 25 bar.
This is little strange with resulta we got

About camshaft timing
Both inlet and exhaust valves where spring pressurised without lifter pressure when leakdown test .

The cam timing has no adjustment

Hard to believe valves are leaking with 27bar compression, but maybe the volvo specification is much higher?

It sounds like bad camshaft timing. This is as critical as IP timing.

[82vdub]

The cam timing actually does have some adjustment. The timing of the cam (in relation to both the crank and injection pump) is what is being talked about here. Maybe the cam is off by a bit, so the valve is opening (or still in the process of closing) much longer when the piston starts to build compression than what it should. Double check TDC piston location to where the cam is supposed to be for proper operation.

I will also say that this post has had me baffled for solutions. You're not the only one that can't figure it out.

[Fatmobile]

Have the mechanical lifters been adjusted lately?

I'd still like to see clear lines between the injectors and at least a piece of clear line going back to the tank.
It can tell things about the injectors and pump, just at a glance.

[reimatic]

Have the mechanical lifters been adjusted lately?

I'd still like to see clear lines between the injectors and at least a piece of clear line going back to the tank.
It can tell things about the injectors and pump, just at a glance.

No i have never adjusted lifters. Checked the gap in beginning of summer. And we checked this also when we did leakdown test

I do not understand point with the clear line on pressurised fuel system
If there is no air in incoming fuel to inj pump. How can be air to / from injectors?

Also about the cam timing

I suspected this in beginning but to check this the engine needs to be removed
And how could this change over time?
I do not know what last owner has done with this but why mess this up?

Also there is a model of pistons that does not work with these injectors, but why would the change pistons, and all 6?

[Fatmobile]

When the injectors "microchannel" they start to piss a stream.
When the cylinders ignite the pressure pushes back past the injectors, through this tiny pissing microchannel and comes out the small lines between the injectors.
Just by glancing you can tell if they are pissing.
I noticed this with a clear line going back to the tank, thinking it was air pulling past a bad mainshaft seal at first.

Something we haven't discussed yet, the banjo bolt on the output of the pump has a restrictor. If you have a regular banjo bolt in it's place; that might show up as air in the fuel even with a slightly pressurized fuel supply because the injection pump will move huge amounts of fuel without it. You won't see it through opaque lines. Enough to cause a vacuum at the front of the pump, but you don't have a fuel pressure gauge either. 2 things all my cars have.
It's a very tiny hole in the bolt, if it cloggs you will see a reduced fuel flow,... if your return line is clear. That would also cause increased pressure in the pump and reduce fuel flow needed to cool the pump.

[reimatic]

faulty injectors caused this.

switched them between the 2 engines and power back.

i had these to 3 different bosch workshops for test, none found them faulty?
did buy 6 new ones to the faulty engine.

now i ordered new nozzles to the other engine, from (competitor's name removed by moderator).
has anyone here tried these cheap model parts?

[Fatmobile]

I don't think most people know how to test injectors.
They just check the breaking pressure without looking at the spray.
It's important to watch what happens at breaking pressure, see if it's pissing slightly right before they break.
A small drip is kind of normal but if it's shooting a small stream off in one direction there is a microchannel.