Re: More Rough Cold Starts...
Posted: Thu Jan 10, 2013 12:28 pm
My best guesses are:403delica wrote:Yah i agree! but i would still love to know why it runs rough after the glow plug cycle
You don't have enough compression (try a leakdown test?) because compression produces heat in a diesel.
Your timing could be off, injecting fuel at the wrong part of the cycle, causing the engine to not fire at the right time and produce less heat.
Dirty injectors.
Since you say that the smoke is black, here is a listing of black smoke diesel problems that should help you track it down:
Black smoke is the most common smoke emitted from diesel engines. It indicates poor and incomplete combustion of the diesel fuel. There are many causes, including…
Incorrect timing
Dirty or worn injectors
Over-fuelling
Faulty turbocharger (ie not enough air to match the fuel)
Incorrect valve clearance
Incorrect air/fuel ratio
Low cylinder compression (eg sticking piston rings or worn components)
Dirty air cleaner
Restricted induction system (eg system too small or kinked inlet piping)
Other engine tune factors
Poor quality fuel
Excessive carbon build up in combustion and exhaust spaces
Cool operating temperatures
Obviously, worn or damaged components must be replaced, and the earlier you identify and fix the problem, the less damage will be done. Keep on top of engine tune issues, including valve adjustments, and regular servicing of air, fuel and oil filters. Do not buy fuel from suspect outlets. Dirty components, such as injectors can be easily restored to full cleanliness by using an effective and reliable fuel system cleaner.
Black smoke is high in carbon or soot, which is an undesirable product of diesel combustion. Now, the combustion of diesel is a complicated process of breaking down the various hydrocarbon fuel molecules into progressively smaller and smaller molecules, by burning in the presence of oxygen. The main and ideal end products of combustion are CO2 and H2O (carbon dioxide, the greenhouse gas and water). It is believed that the last step in the process is carbon monoxide (the poisonous gas) to carbon dioxide. This is also the slowest step by far, and when combustion conditions deteriorate some upstream bottle necking occurs in the chain of combustion reactions. This results (according to some authorities) in polymerization of smaller partly burnt molecules into much larger ones, which become visible as soot, or black smoke.