what would cause a diesel engine to get air into the fuel?

Question

My sister's boyfriend is trying to sell me a chevrolet truck which has a diesel engine in it. Told me that it'll run fine for about a mile, and then it shuts down. Said that it keeps getting air in the lines, and after the air is bled off, it'll start and run but only for a short time again. I'm thinking that it's the fuel pump, but not sure. Say's that he spent over $1000 trying to get it fixed at the dealership, (new filters, lines, ect.), with no luck.
Does anyone know what the problem could be?

Answer 1

It has to be taking in air between the tank and the suction side of the pump. If the lines, filters etc. have all been changed, check all the connection fittings and filter gaskets. If it is taking enough air to shut down in a mile the hole may be bad enough for fuel to leak out when the engine is not running. Often overlooked is the pick up tube inside the tank. They are usually unsupported and vibration can cause a crack that will let air in.

Answer 2

Air In Diesel Fuel System

Answer 3

If it is a Chevy and has an engine that runs on Diesel run away. I have owned 2 Chevy's One had the Duramax in it. The other was an older model. Just cause the truck runs on Diesel doesn't mean it is a Diesel engine. I Have had 3 Cummins Diesel engines in Dodge trucks. If you buy one of them you can bet on several hundred thousand miles on the motor. I know one guy who has 600,000+ on his. Ford seems to hold up pretty well also. Bottom line you talk to a Ford guy he will tell ya theirs are the best. Talk to a Dodge Guy and we will tell ya that the inline is superior by design. Thats why the over the road trucks run In line motors. But even some Chevy guys will tell you to buy Ford or Dodge if you want a Diesel. Chevy needs to stick to the Small block 1/2 tons or get with someone like Cat or Detroit for a motor. Isuzu was not the right one. However the Duramax is Less Bad than their old ones.

Answer 4

You are correct in your understanding of detonation and such. The way around that is direct injection. Direct injection is where the fuel is injected directly into the cylinder usually at the top of the compression stroke. Diesels have always been that way because thats the only way they can work. Originally there was a gear driven mechanical fuel injection pump that both created the 1000's of pounds of pressure needed and distributed to each injector which was also a mechanical device that basically holds closed till the pressure reaches a certain point then it pops open. The newer 'common rail' systems work more like a typical gas multiport system using electronic injectors. There are also direct injected gas engines now.

Answer 5

i would have to say he has a bad fuel pump he needs to take it back to the dealership and talk to the service manager tell him what is going on and have him have the best mechanic work on it it should on ly take him about 1 or 2 hours to figure it out

Answer 6

There is a break in the fuel system somewhere that lets it suck air into the lines.

Answer 7

OKAY, HAVE YOU FIRST CHECK TO SEE IF THERE ARE ANY (DTC) IN OTHER WORDS HAVE YOU HAD THE COMPUTER SCANNED COMPLETELY.

YOU COULD HAVE A BAD DIESEL FUEL PRESSURE REGULATOR.

YOU COULD HAVE BAD INJECTORS.

YOU COULD HAVE A INTERNAL FUEL LEAK.

YOU COULD HAVE A RESTRICTION.

YOU COULD HAVE A BAD FUEL PUMP.

YOU COULD HAVE A BAD FUEL COOLER.

YOU COULD HAVE ANYTHING WRONG.


DEPENDING ON THE YEAR OF YOUR VEHICLE THESE ENGINES HAVE A EXTENDED WARRANTY ON THE INJECTORS, IT HAS BEEN EXTENDED TO 7 YEARS OR 200,000 MILES.

THE RECALL NUMBER IF YOUR VEHICLE FALLS INTO THE CORRECT YEAR WILL BE (04039)

Answer 8

check the seal on top of the fuel tank , it probably sucking air around the seal

Answer 9

stay away stay away.....GM V block diesels are turds/