There are a number of things that can cause a hard to start condition. When experiencing this problem, pump the fuel primer on the engine @ fuel filter. If engine starts quickly, it is likely the fuel filter housing/primer has a small crack in it, allowing air into fuel line. Some other things that cause hard start are included in the service bulletins below.

#PIP3314: 01 02 03 04 6.6L LB7 Duramax Diesel Engine DTC P0093 P1093 - kw data fuel MIL stall hard hose restriction start nostart no - (Feb 2, 2005)

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in the PI.

Condition/Concern:

01 02 03 04 6.6L LB7 Duramax diesel engine hard start, no start, stall or DTC P0093, P1093

Recommendation/Instructions:

Now that you have completed the published diagnostics for an engine hard start, no start, stall or DTC P0093, P1093 with no trouble found, check for a kink in the (foam covered) injection pump inlet hose. The kink can cause a restriction of fuel flow and result in the concern of hard start, no start, stall or DTC P0093, P1093. Note: The normal procedure of measuring the fuel vacuum reading will not indicate this inlet hose restriction, as the gage fitting is located upstream of the injection pump inlet hose. Also Note: The technician may indicate that it requires fuel prime to start or keep the engine running. This may be an indication that the injection pump inlet hose has a restriction.

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Please follow this diagnosis process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.

Models:

(01 02 03 04 6.6 LB7 C2 C3 K2 K3 Chevrolet Silverado, GMC Sierra GMT800)

#04039B: Special Coverage Adjustment - Injectors-Replace - (Nov 19, 2007)

THIS BULLETIN IS BEING REVISED TO ADD 2004 MODEL YEAR TRUCKS. PLEASE DISCARD SPECIAL POLICY BULLETIN NUMBER 04039A, DATED OCTOBER, 2006.

Condition

Some customers of 2001-04 model year Chevrolet Silverado; GMC Sierra; 2003-04 Chevrolet Kodiak and GMC TopKick vehicles, equipped with a 6.6L Duramax Diesel (RPO LB7 - VIN Code 1) engine, may experience vehicle service engine soon (SES) light illumination, low engine power, hard start, and/or fuel in crankcase, requiring injector replacement, as a result of high fuel return rates due to fuel injector body cracks, ball seat erosion, or high pressure seal extrusion (refer to Corporate Bulletin Number 04-06-04-007G and SI).

Special Policy Adjustment

This special policy covers the condition described above for a period of 7 years or 200,000 miles (320,000 km), whichever occurs first, from the date the vehicle was originally placed in service, regardless of ownership. The repairs will be made at no charge to the customer.

Important: This special policy only covers the above noted failure modes, which are identified by high fuel return flow.

For 2001-2002 vehicles covered by Vehicle Service Contracts, all eligible claims with repair orders on or after May 25, 2004, are covered by this special policy and must be submitted using the labor operation codes provided with this bulletin. Claims with repair orders prior to May 25, 2004 must be submitted to the Service Contract provider.

For 2003 vehicles covered by Vehicle Service Contracts, all eligible claims with repair orders on or after October 10, 2006 are covered by this special policy and must be submitted using the labor operation codes provided with this bulletin. Claims with repair orders prior to October 10, 2006 must be submitted to the Service Contract provider.

For 2004 vehicles covered by Vehicle Service Contracts, all eligible claims with repair orders on or after November 19, 2007 are covered by this special coverage and must be submitted using the labor operation codes provided with this bulletin. Claims with repair orders prior to November 19, 2007 must be submitted to the Service Contract provider.

Vehicles Involved

Involved are all 2001-04 model year Chevrolet Silverado, GMC Sierra; 2003-2004 Chevrolet Kodiak and GMC TopKick vehicles equipped with a 6.6L Duramax Diesel (RPO LB7 - VIN Code 1) engine and built within the following start of production to end of production VIN breakpoints:

Check your engine oil. Look for oil level that is over full. Check oil for presence of fuel.

I am sorry, I am trying to give you information on common things to check. I will refer your question to another expert for more advice.