Super (Duty) -Visor advice on cold start

[KYSlowhand]

I want to see a pic of this engine. Lol
Sounds like it could have a PAS.

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Exactly, I don’t know why they would make the distinction for different temps.

If have throttle blades on your engine you probably have a 460.

There is no intake throttling plate on IDI's.

The instructions do say 1/2 throttle to a certain temp, then full throttle below. If they just wanted the high idle it would just say to stab the throttle once and let your foot off, since it would do just that.

The engine is Diesel /not 460- have a bunch of that motor.
? PAS -Passive Air Supply -Non-Turbo definitely.
The air cleaner from outside looks like the Oil-Bath style but has a round paper filter. Underneath the filter-a wire screen to keep mice out? lol. Cannot see what the throttle cable-shaft operates. It seemed logical that controlling the air controls RPM?
Thewespaul posted about the Pump and metering rod adjusts fuel flow {based on RPM / cylinder vacuum?).

 

[franklin2]

The engine is Diesel /not 460- have a bunch of that motor.
? PAS -Passive Air Supply -Non-Turbo definitely.
The air cleaner from outside looks like the Oil-Bath style but has a round paper filter. Underneath the filter-a wire screen to keep mice out? lol. Cannot see what the throttle cable-shaft operates. It seemed logical that controlling the air controls RPM?
Thewespaul posted about the Pump and metering rod adjusts fuel flow {based on RPM / cylinder vacuum?).

Like the others said, diesels do not have throttle blades or throttle bodies. Diesels suck the maximum amount of air at the rpm they are running at all times. The only thing that controls them is the amount of fuel injected through the injectors.

This is the reason you hear sometimes about diesels "running away" out of control, till they blow up. If a uncontrolled source of fuel is introduced into the diesel, if it is enough fuel it will rev and gain rpm till it blows up, the intake manifold is wide open to the air filter and the atmosphere.

 

[79jasper]

Like the others said, diesels do not have throttle blades or throttle bodies. Diesels suck the maximum amount of air at the rpm they are running at all times. The only thing that controls them is the amount of fuel injected through the injectors.

6.9/7.3? No. Some diesels, yes. More for emissions control.

This is the reason you hear sometimes about diesels "running away" out of control, till they blow up. If a uncontrolled source of fuel is introduced into the diesel, if it is enough fuel it will rev and gain rpm till it blows up, the intake manifold is wide open to the air filter and the atmosphere.

I was going for Positive Air Shutoff.
Me thinks hasn't removed whole air cleaner and is seeing the throttle cable going to IP.

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[KYSlowhand]

Like the others said, diesels do not have throttle blades or throttle bodies. Diesels suck the maximum amount of air at the rpm they are running at all times. The only thing that controls them is the amount of fuel injected through the injectors.

This is the reason you hear sometimes about diesels "running away" out of control, till they blow up. If a uncontrolled source of fuel is introduced into the diesel, if it is enough fuel it will rev and gain rpm till it blows up, the intake manifold is wide open to the air filter and the atmosphere.

Appreciate the patience in responses; my lack of mechanic incite in fuel injection-diesel system/comes from a history with low compression carburetor motors. Just received a Ford manual that has IDI diesel INFO. Nice Sunday here warming up, will remove Air Bonnet again and look more at the throttle cable. The cold start Instructions on the Super-Visor work well now to understand why; but my intuition doesn't think dumping more fuel in at low rpm's is the reason. When I did not open throttle it made all kinds of smoke when it did start - and noises like it was choking on too much fuel.

Again, I am a slow-hand "thanks for your support" - [remember the Gallo Bro's -wine makers?]

 

[chillman88]

but my intuition doesn't think dumping more fuel in at low rpm's is the reason. When I did not open throttle it made all kinds of smoke when it did start - and noises like it was choking on too much fuel

First off, if @Thewespaul says opening the throttle doesn't add more fuel I'd believe him since he's had a few of these pumps apart and knows these far better than I do. That being said... I KNOW opening the throttle all the way will change the timing. That would likely be why. When you look at your throttle connection on the IP, notice on the opposite side there is a lever that moves as you actuate the throttle lever. That will retard/advance timing based on throttle position.

My though was based on the fact that in a diesel, more fuel = more heat. Anyone with a pyrometer knows to let off the throttle if your EGT's are going up because of that.

If you're really going to understand these IDI Diesels, you're going to have to "forget" a lot of stuff that you know about the gas engines. Diesels operate very differently, and if you keep assuming based on how gassers work you'll just confuse yourself. Trust me, it's bitten me a few times!

Anyone willing to learn on here will definitely learn a lot. There are lots of great folks on here always willing to help.

 

[Thewespaul]

That’s good thought though, the light load advance arm will ramp the timing down as more throttle is applied. I’d like to do some timing readings with the engine cranking over and see how much the timing changes with throttle change.

 

[chillman88]

the light load advance arm will ramp the timing down as more throttle is applied

Actually the more I thought about it the more it made sense to me. I'm sure you know all about gassers running great with high base timing but not starting with high base timing. Might be a similar principle.

 

[Thewespaul]

Yep that totally makes sense.

 

[The_Josh_Bear]

Actually the more I thought about it the more it made sense to me. I'm sure you know all about gassers running great with high base timing but not starting with high base timing. Might be a similar principle.

On that note years ago before I could time my own engine(by ear or meter) I had some crazy-retarded timing, like 0* BTDC on the pulse meter. That engine would nearly start itself, and actually would start over 75* ambient with no GPs. And not a great starter speed either.

 

[KYSlowhand]

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Took PICs this time NOT shivering-cold hoping the beastie would start !
Found throttle cable was moving very little; but lub'd it.
Throttling up while cranking is good for quick-easy starting this motor.
THNX x2 Gentlemen.

 

[IDIBRONCO]

That being said... I KNOW opening the throttle all the way will change the timing. That would likely be why.

This was also my guess after thinking about it more. I used to have a friend who had a 1966 Harley back in the early 90's. It had a magneto for the ignition. He said the he had to leave it just loose enough to turn by hand and tight enough to stay in place while the engine was running. He said that he had to retard the timing in order to start it. (I also think that it had high compression), and then would have to advance it again after it was running.

 

[FordGuy100]

I would think on a cold start you would want a lot of advance in the timing so that the fuel has more time in the cylinder to burn.

The real test would be to determine how much timing is pulled with the throttle all the way open, adjust base timing minus that amount, and do a cold start to see how it does.

 

[KYSlowhand]

The_Josh_Bear On that note years ago before I could time my own engine(by ear or meter) I had some crazy-retarded timing, like 0* BTDC on the pulse meter. That engine would nearly start itself, and actually would start over 75* ambient with no GPs. And not a great starter speed either.[/QUOTE]

IDIBRONCO ... a friend who had a 1966 Harley back in the early 90's. It had a magneto for the ignition.... he had to retard the timing in order to start it. (I also think that it had high compression), and then would have to advance it again after it was running.

Ignition/combustion Timing for starting is primo; for Kick-started Harley motors if you did not kick completely thru (0* BTDC) it would reverse the piston/ crank travel "Kick-back, like a Mule". Retarding was done manually by a cable attached to the distributor/magneto.

Having my own personal diesel-dinosaur-Oil burner, I am impressed and somewhat intimidated by the reasons behind the Super-Visor directions but know how to get the Beastie to cold start in winter now;

 

[DrCharles]

I'm a bit late to this party, but...
As already pointed out, our IDI's do not have any throttles in the air intake.

However, my old '73 Mercedes 220D did indeed have a throttle body, with a ported vacuum line that ran to a diaphragm on the Bosch injection pump - the IP actually was regulated by vacuum way back then. Idle was still set mechanically though. Somewhere around '76 MB went to an all-mechanical pump.

 

[IDIBRONCO]

for Kick-started Harley motors if you did not kick completely thru (0* BTDC) it would reverse the piston/ crank travel "Kick-back, like a Mule". Retarding was done manually by a cable attached to the distributor/magneto.

That's funny because he was a smaller guy and he was thrown over the bars at least twice. His didn't have a cable to retard the timing so he did it by hand.