Super (Duty) -Visor advice on cold start

[KYSlowhand]

My '88 IDI was not liking to cold start, on the third try it rattled to life; making noises as if a rod had broken or a valve dropped. Looked for an owners manual [didn't find it] Thankfully the engine seemed to forgive my method of cold starting. Found the SuperDuty-visor which has instructions advising below 32 degrees open throttle fully- at more moderate temperatures use half throttle. Next time I will follow instructions.

I assume this advice works because more air- Oxygen makes ignition of the "cold" fuel easier; and the Super-visor Instructions very important to cold starting the IDI engines ?

Worked out good , think this is a keeper but I'm sure other engines with electronic controls do not need this throttle positioning to help cold starts.

 

[nelstomlinson]

Open throttle? Diesels don't have a throttle which reduces air flow. Standing on the gas pedal should just get the pump to push a little more fuel through the injector. Maybe it advances the timing a bit? That might be a good thing?

I've been starting my IDIs in below zero temperatures for months now. Plugging it in overnight is the best answer. Having your glow plugs, wiring and controller in good shape is essential. You need good batteries and a starter that will spin it fast. Just a tiny whiff of starting fluid can help get some heat into the cylinders if all else fails.

 

[chillman88]

Opening the throttle should add more fuel I believe. Mine is always much more willing to cold start when I do that.

Mine will start without flooring it, but it starts much quicker when following the directions.

 

[MtnHaul]

Of course few of us really like the idea of full throttle before full oil pressure but perhaps it's safer than it seems.

 

[FordGuy100]

What its saying to do is depress the throttle while cranking and then releasing once it fires, not actually revving it up after it starts.

Of course few of us really like the idea of full throttle before full oil pressure but perhaps it's safer than it seems.

 

[KYSlowhand]

About 32 degrees when starting the 7.3 IDI engine today; opened throttle full, waited for glow plugs to heat and fired first time; believe I could have used just half throttle.

 

[Thewespaul]

The pedal won’t change cranking fuel, that’s controlled my the metering valve which will be wide open already when cranking. The only reason they want you to depress the pedal is for the high idle to kick in

 

[IDIBRONCO]

The only reason they want you to depress the pedal is for the high idle to kick in

It has to be more than that. The high idle will kick in with the same amount of throttle opening whether it's 35 or -10 degrees. The instructions do say to use full throttle to start when it's lower than 32 degrees.

 

[Thewespaul]

Maybe, but as far as the pump I don’t see anything, your cranking fuel will not change on the test stand whether it’s full throttle or idle, the cranking rpm will affect it more.

 

[KYSlowhand]

What its saying to do is depress the throttle while cranking and then releasing once it fires, not actually revving it up after it starts.

Opening the throttle should add more fuel I believe. Mine is always much more willing to cold start when I do that.
Mine will start without flooring it, but it starts much quicker when following the directions.

It has to be more than that. The high idle will kick in with the same amount of throttle opening whether it's 35 or -10 degrees. The instructions do say to use full throttle to start when it's lower than 32 degrees.

Maybe, but as far as the pump I don’t see anything, your cranking fuel will not change on the test stand whether it’s full throttle or idle, the cranking rpm will affect it more.

The pedal won’t change cranking fuel, that’s controlled my the metering valve which will be wide open already when cranking. The only reason they want you to depress the pedal is for the high idle to kick in

Chilliman88
Look under the air cleaner the IDI throttle-pedal- moves a cable > that turns a shaft on the side of the intake; no fuel there to control - just the air coming through the air cleaner. Opening the throttle on these engines allows air [not mixed w/Fuel] to get into the cylinders. Then IDI system supplies the fuel.

Obviously the diesel injection pump can supply more than enough fuel, if you have seen the black smoke from less than optimum performing engines you are seeing too much fuel and not enough air. Because of the awesome compression the mixture needed to start a diesel can be difficult.
I just held the throttle open but as Thewes-Paul added opening the throttle as cranking is probably better for cold starting.

Thanks for your QUOTE's / support

 

[chillman88]

Look under the air cleaner the IDI throttle-pedal- moves a cable > that turns a shaft on the side of the intake; no fuel there to control - just the air coming through the air cleaner.

Never seen an IDI like that. The throttle cable actuates a lever on the injection pump. These engines have no flap to control air going into the engine.

 

[FordGuy100]

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.

 

[Thewespaul]

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.

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.

 

[hce]

Not going to say what it does, but full throttle does aid it cold starts. All 8 cylinders seem to come on at once opposed to running rough before all 8 are firing consistently. I consider cold starts are 0 and below, above zero is just a walk in the park. Older diesels actually had an overfuel button allowing the throttle to be further applied then normal operating conditions for starting.

 

[79jasper]

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

Sent from my SM-N960U using Tapatalk