Cold starting very hard, high EGT

[Knugcab]

Engine: 1985 SD25 in a 720. Euro version with the Bosch VE clone (from what I recall, US versions have another pump?).

Cold starting was impossible when I bought it. It was "willing" to ignite all the time, but was just pouring out greyish smoke, had to use block heater or heatgun in the aircleaner to start. Started immediately when using block heater or heatgun, though running rough for a while (some cylinders missing) when not using block heater.

Swapped out the glow plugs from 1985 (yes still the stock plugs in engine! ) for brand new ones, then it starts after glowing a couple of times and after very long cranking. Never on the first try.

Valve clearance checked yesterday, it was perfect.

No starting problems at all when the engine is hot, running on all cylinders when hot, no smoke from the exhaust except for some black smoke on full throttle which seems to be pretty normal for a diesel engine before any emission requirements, though it is pretty gutless. I don't except much from 72 hp in an almost 1700 kg vehicle with 31" tyres, but.....

But the EGT must be very high since after just a short time of running, the exhaust tip is hot enough to burn your hands on... So I started to think that the pump timing is way off? And if that may be the source of the hard starting and gutlessness?

Haven't had the time to check compression yet, neither the injectors (which according to the PO was swapped for new ones some years ago and pressure etc. checked by an experienced diesel mechanic). Though the mileage is quite low (170 000 kilometers if the odometer is correct) so I would be surprised if the cylinder liners are worn out..... Also, there is not very much blowing from the oil filler hole, the oil consumption is normal and no blue smoke. Of course, low compression can have other reasons....

Ideas? May I be into something with my pump timing theory?

[plenzen]

First off welcome to the forum

I too have an SD25 with the VE pump. Up until I had the pump rebuilt for leaking O rings etc the truck would start even at -20C. I did however install an air heater but after 2 or 3 times it would go. Since the pump rebuild I have a hard time at -5 or or 10 with it.
Is yours equipped with the CSD ( cold start device ) located at the bottom of the pump ? I wonder if it does not have something to do with that or with the transfer pump inside. I don't drive it all that much anymore and have just got used to cycling the air heater on for a few more seconds. Im not that sure that advancing the "ignition" timing will help but something inside the pump may need to be readjusted. I have not had the ambition to dig it off again and take it back to the rebuilder for them to bench check it.
As nothing had changed on my engine from when it was starting fine and leaking fuel to when I got the pump back and was hard(er) to start you are probably on to something.

I am sure that this will annoy me enough to finally take action and take it back to them to check.

Keep us posted as to what you do .

P