Injector and injection VP engines

[Rufduck]

Can someone help with some VP D1-30 engine fuel injector questions...

-There is what looks like an Allen screw hole on the side of the injector holder (7). There is no screw in it and it appears to go nowhere. All three injectors are the same. What is it?
-What is the purpose of the washer (8)? I know what it does, it seals between the fuel return manifold and the injector holder but what is the purpose of fuel there? Cooling the injector?
-Can I reuse washer (7) if intact?
-Is the injector nozzle (2) supposed to be flat across the tip where the needle protrudes? All three of mine have what appears to be a 2-3mm diameter crater around the needle.

I shall do a “pop” test to determine leaking and function.

I did a compression test through the glo plug hole. The manual say 2450psi @ 250rpm. I have all three cylinders @ nearly 3000psi after 4 revolutions and nearly 5000psi after 10. No significant variation between the three. Engine warm @ 150*f, battery charged.
-Any concerns with these readings?
Attached Thumbnails

[Compass790]

If you get no reply PM DougR, he knows Volvos.
If washer 8 is copper you can anneal it on the gas stove & re-use I think.


I did that on my injection pump & injector on a yanmar but there is a limit to how many times you can do that as they get thinner & wider.

[Rufduck]

Thank you, had forgotten that trick. Have refaced them with solder and lapped them true with 600 and a glass window. Not forgetting to redrill the holes.
Cheers

[skipperpete]

Originally Posted by Rufduck

Can someone help with some VP D1-30 engine fuel injector questions...



-There is what looks like an Allen screw hole on the side of the injector holder (7). There is no screw in it and it appears to go nowhere. All three injectors are the same. What is it?

-What is the purpose of the washer (8)? I know what it does, it seals between the fuel return manifold and the injector holder but what is the purpose of fuel there? Cooling the injector?

-Can I reuse washer (7) if intact?

-Is the injector nozzle (2) supposed to be flat across the tip where the needle protrudes? All three of mine have what appears to be a 2-3mm diameter crater around the needle.



I shall do a “pop” test to determine leaking and function.



I did a compression test through the glo plug hole. The manual say 2450psi @ 250rpm. I have all three cylinders @ nearly 3000psi after 4 revolutions and nearly 5000psi after 10. No significant variation between the three. Engine warm @ 150*f, battery charged.

-Any concerns with these readings?

Attached Thumbnails

The washer with the two holes seals the leak off/return gallery banjo and is usually aluminium. Yes you can re use it.
The compression readings you quoted are unrealistic and you may have a gauge problem, injector nozzle pressures are more in that region of 2500 -3,000 psi but do not significantly vary from the set pressure with rpm. Inspect those injector tip craters VERY closely, it is unusual to see a machined crater on an injector nozzle but a flame eroded nozzle usually indicates a problem. Is the pintle still intact or has it vanished?
Pete.