Petter PAZ1 Injector Nozzle

Hi.
I am located in Ireland and new to the forum. I have a number of working old engines including a PAZ1 and a Lister HR2.

At the moment I have an issue with the Petter PAZ1. It is in a Benford BRJ31332 Towable mixer manufactured in 1960.
It was smokey but working well until last summer. This winter, I was unable to start it.
I cleaned the head, ground the valves, fitted a new gasket and took the injector to my local diesel repair shop. It was fitted with a 3 hole nozzle and the guy said this nozzle was incorrect and replaced it with a 2 hole nozzle (HL120S20B249P3). Most of the documentation would suggest that he was right however I have been unable to get the engine to fire since fitting it. The compression seems good and the engine smokes but does not fire. PAZ1 Operators Manual (Publication 2086/4) describes a 2 hole nozzle in the injector section but Publication 2086/7 describes a 3 hole nozzle in the injector test paragraph. There are no marking on my engine and I do not know the date/series and if it is the original mixer engine. The flywheel has no cooling fins, the decompressor lever is the later type and the fuel tank looks like the earlier type. Are some PAZ1 model be fitted with a 3 hole nozzle ? Any comments/suggestions welcome.

Hi and a warm welcome to the forum.

I checked my manual and can confirm your observation re number of holes in nozzle.
Hopefully someone else can help out but maybe a timing issue?

Thanks Woodsman,
I also considered a possible timing issue. I can hear the injector releasing as I hand crank the engine. I checked the spill timing and it was set to 26 degrees BTDC. I tried adjusting to 23 degrees but it made no difference. (the flywheel has 2 marks). The release pressure of the injector will also influence the timing. The diesel repair shop set the pressure of the new nozzle at 186 bar. I tried reducing the pressure to 2250 PSI but it also made no difference. It may still be a timing issue but I have not isolated it yet.

If you reduced the injector pressure that will affect the spray pattern which will effect how the engine will run.

Maryalice

Maryalice, yes I agree. I think the 2250 PSI is closer to the correct release pressure and if necessary I can re-adjust later. I think I have identified another issue this morning that may be contributing to the engine not firing/starting. There is significant wear on the crankshaft bearing shells. I will pull out the piston later this week, investigate further and then update. Even if the shells are an issue, I am still interested in the injector nozzle question.