I need an education on the 093 code error

[HighMiles]

I have an early 01' D/A with 180k. At 60k I got my first 093 trying to pass on the freeway. Took it in and ended up with a new fuel pump and couple of injectors. All was fine for awhile with frequent filter changes and watching for the better fuel stations, and running light loads and a light foot. At about 135k I bought a trailer and soon began getting the "Service Light" and "safe mode" and I tried filter changes hoping it would go away. This problem came up every time I put an extra load on the truck. I brought it back to the Dealer for another two week stay and they put in a full set of injectors (thank you GM at 155k and under warranty) but soon after same thing. Again the Dealer had changed the filter and sent me on my way. It did not help so they recommended I bring it in for an extended stay (this is my office on wheels). At 180K I get it in and after a 1-1/2 weeks they decide one of the fuel lines has a flat spot in the braided area and this was causing a restiction creating the problem, I disagreed but they said they can't go further until I agree to replace the fuel lines for $545.00 US. Same problem after one week to get the parts and install them. Next step in the diagnostics brings them to the high pressure side of the fuel pump, $1200.00 estimated to replace. The dealer indicated the weak fuel line stressed the fuel pump causing it to fail. I entered a claim to GM customer service and of coarse it was declined due to the mileage.

My questions:

Why would it show a large fuel leak if it is starving for fuel? (by the way, no fuel in the oil)

Could a fuel restriction cause a pump to wear out?

If the fuel line could cause this and it is not the result of damage from first report of the problem at 60K, should this be my problem or warranty?

After the fuel pump what next?

Could it be in the electronics?

If it is my problem are there other fixes for this since it is not under warranty anymore?

Thanks for all who post here, it has been very helpful for me but now I am stumped.

[More Power]

A search of this forum for the keyword "093" yields a couple dozen topic threads dealing with diagnostic trouble code P0093. Have a look...

MP

[HighMiles]

I had already searched for 093 and fuel pumps. I was hoping for bit of technical advice. It seems the mechanics at my Dealer are very text book and robotic and really don't know their product beyond that. I have gotten better information off this site. Maybe someone knows who has a really good Duramax mechanic anywhere in the Detroit area.

[madmatt]

A#1- IF YOUR PUMP LACKS THE NESSACARY VOLUME IT CANNOT CREATE ENOUGH PRESSURE TO MEET THE COMMANDED PRESSURE AND CREATES A PRESSURE DIFFERENCE OF MORE THEN 20MPA BETWEEN THE ACTUAL AND COMMANDED PRESSURES.

A#2-YES.

A#3-MAYBE, I DON'T THINK THE POWERTRAIN WAR. COVERS THE LINE I THINK YOU ARE TALKING ABOUT.

A#4-I OBVIOUSLY CAN'T DIAG YOUR TRUCK IN MI, BUT BEFORE I THREW A PUMP @ IT, I'D TRY A FUEL PRESSURE REG. OR A FUEL RAIL PRESSURE SENSOR. BOTH COULD CAUSE THIS CODE AND ARE CHEAPER THEN A PUMP. THE PUMPS ARE ACTUALLY PRETTY STURDY.

A#5- YES. POSSIBLE ECM OR FRP SENSOR.

A#6-SEE A#4 OR E-MAIL ME @ MATTWOERTZ@MSN.COM AND I CAN SEND YOU SOME MORE IN DETAIL DIAG. INSTRUCTIONS OR HELP IN ANY WAY I CAN. HOPE THIS HELPED.

[madmatt]

ALSO I NOTICED YOU SAID YOU HAD A SERVICE LIGHT AND SAFE MODE MESSAGE. I ASSUME A P0093 ACOMPANIED THESE MESSAGES?

[HighMiles]

What I should have said is it goes into the "safe mode" and only allowing 2K RPM which if you feather the pedal you can get up to 65 MPH on a flat road. The "Service Engine" also comes on and when checked it is the 0093 code. The safe mode is cancelled when the truck is shut off for a few minutes. The light stays on for only a few on/off cycles.

Thanks for all your help.

[Travis Baker]

I now have about 120k on my truck. Have had problems ever since I got it. Currently I am experiencing problems similar to yours. Could it be the injectors?

[madmatt]

TRAVIS,
WOULD NEED MORE INFO ON SYMPTOMS,IE...CODES, SMOKE, SHIFTING FUNNY, ROUGH IDLE, ETC...YES THOUGH INJECTORS MAY CAUSE THIS ALTHOUGH IN HIGH MILES CASE PROBABLY NOT.

[mechanicwillie]

hi the dealer should put a vac guage on the port right front of the engine at 2000 rpm there should be no more than 2.5 to 3 inchs at 2000 rpm.i have seen and repair problems in the fuel tank sending unit.there is a check valve in the bottom of the sending unit it will not allow fuel to enter the reserve bowl.