Hard Start
 

Just re-read the sticky, but I have a few questions.
1. Will the car start with a bad GP? Sticky says no but my hard start condition makes me think it is glow related. When cold, the car will crank for 5-10 seconds before starting unless I let the GPs energize 3 or 4 times. Of course, this isn't an issue when the motor is warm. The fact that it is hard to start after sitting makes me think air ingress, but that doesn't seem consistent with it being easier to start with the plugs energized a few times.

2. Is it possible my plugs are not up to spec? I'm not much of a believer in one brand being necessarily absolutely superior to another, but I wonder if these off-brand (wholesaler discount, they were listed as champion but came as something else marked "replaces champion") are just a little weaker than oem. They are brand new, so I don't think one could have died already, but perhaps they just take 3-4 times longer to get as hot as a good bosch plug. I'm planning on replacing them just 'cause, but want to fault trace a little before I just throw money at it.

Door number three is maybe this motor is tired and doesn't make good compression, although it sounds healthy to my ear, doesn't consume much oil or smoke much, and feels pretty strong. It has somewhere around 275k on it, and was rebuilt once around 120k. Thoughts?

Glow plugs would be a good starting point. In cold weather, with a motor even in only halfway decent condition, these cars fire instantly with 6 good plugs - should start so fast that you barely have time to hear the starter run. With one dead plug it should start fast, but skip until the cyl with the dead plug lights. With two dead plugs starting is harder, and with three or more there's a good chance it will never start.

Glow plug quality matters too though. Bosch plugs are the only one to use in this engine. Champions and Autolites are easier to find but often heat more slowly, or heat in the wrong place, seen a few that heated up the base rather than the tip. They also can have a short life, especially if they run for longer designed or run with the engine running and alt charging due to a glow control issue - I remember you described some relay problems so that could have killed a few. The Bosch Duraterm plugs are self-regulating so they don't get killed as quickly by this. If you have some dead plugs that would not be a large surprise.

Compression issue is not too likely based on your description, typically with these, the first sign of a tired engine is difficult *warm* starting or smoke/oil use. However if the glow plugs don't give you progress, there are some other possibilities
- valve lash - check it, adjust if needed (cold engine only)
- injection and/or cam timing - check, adjust if needed (special tools required but available for free loan or cheap purchase on ebay, under $50)
- air leakage into fuel system - the fact that multiple glow cycles affects ease of starting for you makes this less likely, but possible. Any signs/smell of diesel fuel leakage under the hood? Does it take longer to start if parked facing uphill vs downhill?

Thanks for your detailed response. It definitely doesn't start quickly under any condition other than it's been running for some time and is immediately re-started. I suppose I should replace the plugs, it's just #5 and especially 6 were so difficult I was hoping not to do it again for a while. I've read there's an easier way involving removing the injector hard lines and vacuum pump, I'll have to look at that again.

The relay issue is resolved now, but that could be a clue. Afaik the plugs were never energized for much longer than they would be normally, but from what you say it sounds like having them on when the car is running shortens their life. A few times I had to get out and tap on the relay to get it to shut off after the car started. In any event, it was as difficult to start even when the plugs were brand new. I have the updated relay now, I was hoping that might be part of the issue but it seems unrelated.

-Valve lash does need to be adjusted, last record of service is in something like 1994. I've been putting that off, but if it could be related I will look into it.
-I set the inj pump to .90mm. Initially I had it set to .75 (cali spec), but it runs much stronger, quieter and smokes less at .90. I have all the tools for that.
-There is a small leak at injector 6 around the base of the injector. Just enough I can see small air bubbles when it is running, not enough to leave a drip. I'm not sure what the procedure to deal with that is, none of my greenbooks cover it. I don't know about uphill/downhill, I only ever park on flat.

The leak you are noticing could make a difference, especially if you also have a marginal fuel filter that's pulling a vacuum on the supply and sucking fuel back when you shut down. If you are seeing it at the bottom of the injector it is probably coming from one of the small (3mm) rubber return lines, easy to fix. The injectors themselves don't tend to leak but those lines are a routine wear item, if one leaks not a bad idea to do them all.

Replacing fuel filter never hurts either.

Again, though, a fuel delivery issue is made less likely by your statement that letting the plugs run multiple times makes it start faster. That suggests you are looking at a mechanical or glow related cause.

Did you check cam timing when you retimed the pump? Worth checking when you look at valve lash, you will have the valve cover off anyway. Remember to use the new style reusable rubber valve cover gasket (unless you already have it), the cork ones always leak.

Strong cranking speed also is important, got the correct size large Group 93 battery in good shape? Good cables, terminals, starter?

I thought I replied to this earlier, but the leak was coming from one of the small return lines. So that was an easy fix. The fuel filter is also new.

I'm not 100% on cam timing, I would have to look more into that. The battery is good. I'm thinking it must be the plugs, but I can live with cycling the key for now. If I ever resolve the issue I'll update this thread.