Rough cold start

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isuzu Specialities
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Re: Rough cold start

Post by isuzu Specialities »

This symptom is due to low fuel pressure, excessive fueling amount or coolant leaking into the cylinders.

First thing to do is check your engine oil level. If the oil level is higher than when you filled it, there is your problem. If your oil level is about where you filled it to, smell the oil, does it smell like diesel?

Next
When trying to start the engine crack open a high-pressure fuel hose at the fuel injector while you are cranking over the engine.
Do this until a strong stream of fuel spits out. At this point, you will tighten the fuel line before you stop cranking the engine over.
Repeat this for each one of the injectors.

Finally
After the engine is running squeeze the top radiator hose tightly. Do you feel air bubbles flowing thu it? Do the bubbles in the hose feel as if they have a rhythm to it? if so you have a leaking head gasket.

almost forgot
Chack your radiator. Check to see if its full & most importantly check to see that's its not full of diesel.
isuzu Specialities
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Joined: Sun Feb 04, 2024 2:20 am
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Re: Rough cold start

Post by isuzu Specialities »

Symptom of incomplete combustion.
Incomplete combustion is caused by a couple different ways.
The first being low compression due to valve adjustment incorrect, excessive slop in timing components, faulty piston rings and broken valves.

The other area is low injection fuel pressure.
This can be caused by faulty injectors, air entering the fuel system, faulty injection pump. Clogged fuel filter & fuel contamination. Lowe PWM control signal for electronic control system.

The air leaks that I and others hear won't effect the starting of the engine. Charge air pressure leaks causes a entirely different set of symptoms. Charge air pressure doesn't become important until higher RPM & higher engine loads.
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JoeIsuzu
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Re: Rough cold start

Post by JoeIsuzu »

isuzu Specialities wrote: Sun Oct 27, 2024 12:26 pm The air leaks that I and others hear won't effect the starting of the engine. Charge air pressure leaks causes a entirely different set of symptoms. Charge air pressure doesn't become important until higher RPM & higher engine loads.
Please clarify. I don't know what "charge air leaks" are.

But in general, when anybody here refers to "air leaks" causing starting issues, they are referring to air leakage INTO a fuel line that should be pulling in fuel (not air). In my experience, they may well be the #1 cause of starting issues with the C223 engine (the only rival would be glow system issues).
isuzu Specialities wrote: Fri Oct 25, 2024 5:00 am This symptom is due to low fuel pressure, excessive fueling amount or coolant leaking into the cylinders.

First thing to do is check your engine oil level. If the oil level is higher than when you filled it, there is your problem. If your oil level is about where you filled it to, smell the oil, does it smell like diesel?

Next
When trying to start the engine crack open a high-pressure fuel hose at the fuel injector while you are cranking over the engine.
Do this until a strong stream of fuel spits out. At this point, you will tighten the fuel line before you stop cranking the engine over.
Repeat this for each one of the injectors.

Finally
After the engine is running squeeze the top radiator hose tightly. Do you feel air bubbles flowing thu it? Do the bubbles in the hose feel as if they have a rhythm to it? if so you have a leaking head gasket.

almost forgot
Chack your radiator. Check to see if its full & most importantly check to see that's its not full of diesel.
These may indeed be relevant, but they I'd consider them all "one-off" cases that should be looked at after other issues have been ruled out.

Jack
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