Originally Posted by Jolly Roger
One of my best excavater s had a problem starting after setting and it was because of a broken glow plug wire in the frame somewhere and short term we ran a new hot wire from the battery to the bar that connected all the plugs (on a 4 cyl in this situation ) wire nutted it and used it as needed? It took two people to start it when needed to touch the hot wire to the bar while cranking but it was temporary and worked at the time.
Well done! I did the same thing for a friend's Bobcat skid loader last year. I needed to test for leaks after replacing a hydraulic hose late in the fall but it was such a bear to start and battery was in poor condition it would run the battery dead cranking. I figured out the glow plugs weren't getting power when the switch was pushed, so used a jumper wire to heat them up 10 seconds or so and then climbed into the cab and turned the key. I think he still does it that way; he never did bring it back for a proper fix.
The cold start aid seems like a good place to begin. Some engines just don't have one, but at least go looking and verify operation if you find glow plugs or grid heater.
I don't know about the filter being a problem -- did you have any trouble with low engine power when it was run last? When you did finally get it started, did it run fine? I'd think if a filter were causing a starting problem it would also cause running problems.
I'm not familiar with your injection system. Does it have some kind of electric lift pump? Is it working? My ISC (as an entirely unrelated anecdotal example) runs a lift pump only in the beginning; the injection pump is designed to pull fuel all the way from the tank once the engine is running.