I'm new to the forum and new to diesels. I purchased a 1978 Oshkosh P-2323-5 4X4 snow plow at auction this summer. It's an old county plow that was kept in a heated shed. They never needed to use the glow plugs and it didn't have a block heater installed.

I pre-heated it the other day and was plowing snow for 1.5 hours. Then it began to lose power. I pushed in the clutch but the engine kept decelerating and would not respond to the throttle and stopped. It turned over well but was reluctant to fire. Eventually it did but was running weak. After quite a few seconds it began to respond normally. This episode repeated itself four more times before I got it back in the shed.

Any ideas? Fuel filter blocked, low fuel pressure, blocked air filter (snow maybe, but not likely?), gelling? I topped the tanks with off road #1 Diesel with no additive.

Thanks,

Jim

 

fuel filter, and probably any rubber lines are deteriorating. I would not go for gelling or a blocked air filter yet. the symptoms you describe are the engine running out of fuel. Your best bet is to change the filter, and have a few spares on hand, this thing hasn't run much, and might have a lot of crap in the system.

Also, if the lines look old at all, change them out.

If it has the hand primer pump on the side of the engine, check it for leaks, the o-ring is prone to failure, and will allow it to get air in the system.

Good luck

 

Pretty much what pind said.

We had a Cat 3208 that started doing the same thing, found a pin hole in the bottom of the fuel filter.

 

A CAT 3306 is a bulletproof old engine. I wish they still made them. Anyway, same as others have said, check the simple stuff first. Change the filters. If it still acts up on ya, connect a temporary hose from the inlet side of the transfer pump and drop it into a 5 gallon bucket of diesel fuel. Prime it up and start it, see if it continues to act up.
YOu can install a hose on the outlet side of the transfer pump and spin the engien over and check for pump volume, then connect it directly to the injection pump inlet (bypass filter bases) BUT, only do this with CLEAN fuel and bucket since you will have no filtration.


The old hand priming pumps have two small check valves in them, I have seen these check valves act foolish and cause a low fuel pressure condition.
Also, check the linkage on the shutoff at the back of the injection pump to make sure its not limiting rack travel.