6V53

"Hello,

I have two problems

"Hello,

I have two problems that may be related to each other.

I have a pair of 6v53'turbo with around 600 hrs on them and starboard engine has been pulsing at idle and jumps rpm +/- 200 to 300 and ok above 1800 rmp. This engine does this all the time. I'm thinking maybe a vacume leak?? Any suggestions.

Here is the second problem which I need to resolve.

Yesterday after running about 2 hrs engine started to drop rpm from 2100 and gradually stalled, could not get it started. After about 5 minutes engine started but after a few minutes same thing. At this point I headed in on other engine. Tried several to start again but no go. Here is the frustrating part as other times I can run all day with no problems. I replaced all primary and secondary fuel filters last month. Checked filters today and canisters were full and clean as I thought maybe it sucked sludge or debris from the tank. The strange thing is the engine started today.

Thanks for any input you can throw at me.

Jim"

"things to look at,check fuel

"things to look at,check fuel pressure,f/p 45/70 min 35 psi mit have sticking inj,woren gov,"

"You mentioned a vacuum leak,

"You mentioned a vacuum leak, does anyone know if Diesels in general generate more than a few pounds (or any at all) of vacuum? I know in diesel trucks you need a vacuum pump to be able to run a brake booster. Thanks, and sorry to divert the thread."

"To answer Tucker's questi

"To answer Tucker's question,

4 stroke cycle diesel engines do not ACCUMULATE any appreciable vacuum like a 4 stroke cycle GASEOUS fueled (gasoline, propane, natural gas) engine does. The reason is that the fuel is injected, in liquid form, directly into the combustion chamber at extremely high pressures in order to atomize and vaporize the larger diesel molecule.

Gasoline, conversly, is introduced and mixed with the air stream entering the engine prior to the combustion chamber. On a carbureted gasoline engine the fuel enters the intake manifold drectly below the throttle plate. On a fuel injected gas engine the fuel enters either the intake manifold though a "throttle body" or it enters intake manifold "runners" in a sequential injection system. That is why a "throttle plate" is utilized to control the amount of air entering a gas engine. As a result,the throttle plate affords a means of speed control. When that throttle plate is closed, or even partially closed, appreciable vacuum is created underneath it and can be used to operate accessories such as brake boosters and blend doors.

All diesels are speed controlled by governors controlling fuel delivery only and the intake is basically an open hole with as little restriction as the designer can build in. So, there is no throttle plate and therefore, no ACCUMULATED vacuum that is usefull for accessories.

So, to answer your question directly, a diesel engine DOES create SUCTION to bring air into the combustion chamber but does not accumulate vacuum.

The efficiency of the suction is directly affected and focused by the intake opening and could be comprimised by leaking intake gaskets. But, more importantly than that is the air entering the engine needs to be filtered and any gaps for unfiltered air to enter the engine will eventually destroy it.

Are you getting sleepy now;~)"

"Not sleepy at all, thanks for

"Not sleepy at all, thanks for the education."