I suppose this could be considered a general topic but I'm going to base this on my 1993 Diesel 3/4 ton. Now, I've got some questions that need answered and keep in mind I'm by far a diesel mechanic so go easy on me eh.

First off when if comes to playing with the Injector pump, I have been told that turning up the fuel input can make it so the truck burns too rich and burns the top of the pistons out. And on the other hand, have been told you cannot 'overfuel' and there's not really any harm whatsoever. So basically all I'm asking for is a yes or no with a general explanation, thus ending this arguement. Also, if you can elaborate the possitive and negative effects of increaing the input, it would much benefit my knowledge as well.

Thanks

 

Yes, you can overfuel the engine and melt the pistons. The more fuel you add the hotter it gets inside the cylinder. This is why those of us who have "turned up" our trucks have a pyrometer gauge, to monitor the temps inside the engine to prevent damage due to overfueling.

 

Basically, more fuel makes more heat and exhaust which spins the turbo faster increasing power. but there is a limit. You can turn up your pump to the point it runs away. Do a search and theres plenty of reading.

 

Since the speed of the engine , is controlled by fuel , would the engine not gain rpm in a situation where more fuel is added?

 

Yes, but it doesn't gain RPM fast enough to hit the governor and defuel in the higher gears - especially when pulling a heavy trailer, so you can still melt things down easily.