Chevy/GMC Duramax 01-04 LB7 Discussion of Chevy and GMC Trucks with LB7 Duramax Turbo Diesel Engines

2003 Duramax will not start engine is hot without prime.

  #1  
Old 04-17-2010, 08:17 PM
ArmyDawg's Avatar
Newbie
Thread Starter
Join Date: Apr 2010
Posts: 6
Likes: 0
Received 0 Likes on 0 Posts
Default 2003 Duramax will not start engine is hot without prime.

Having trouble restarting my 2003 Duramax when it has warmed up for 10 minutes or more.

Symptoms:


No codes

Starts cold with in seconds
Runs great
No smoke
No loss of power
No fuel in crankcase oil
Replaced fuel filter with in 100 miles
Replaced fuel filter/primer pump with in 100 miles
Will start when engine is hot after depressing primer pump 4 or 5 times (until firm)

Wife ran truck out of fuel 500 miles ago

Altinator went bad 600 miles ago.

Replaced one battery 450 miles ago

Any Ideas anyone
 
  #2  
Old 04-17-2010, 08:21 PM
12vcummins96's Avatar
Administrator

Join Date: Aug 2009
Location: Pearland Tx
Posts: 5,765
Received 340 Likes on 273 Posts
Default

sounds like a bad cp3
 
  #3  
Old 04-17-2010, 08:24 PM
ArmyDawg's Avatar
Newbie
Thread Starter
Join Date: Apr 2010
Posts: 6
Likes: 0
Received 0 Likes on 0 Posts
Default

My ignorance
What is a CP3?
 
  #4  
Old 04-17-2010, 08:32 PM
12vcummins96's Avatar
Administrator

Join Date: Aug 2009
Location: Pearland Tx
Posts: 5,765
Received 340 Likes on 273 Posts
Default

the injector pump
 
  #5  
Old 04-17-2010, 08:32 PM
ArmyDawg's Avatar
Newbie
Thread Starter
Join Date: Apr 2010
Posts: 6
Likes: 0
Received 0 Likes on 0 Posts
Default

Thanks for the suggestion.

How do you check out the CP3 Fuel pump regulator?

Engine idles fine

ECM lost VIN after altenator went bad and truck almost shut down when batteries went dead.

Replaced ECM
 
  #6  
Old 04-17-2010, 08:33 PM
12vcummins96's Avatar
Administrator

Join Date: Aug 2009
Location: Pearland Tx
Posts: 5,765
Received 340 Likes on 273 Posts
Default

do you have a rail pressure guage
 
  #7  
Old 04-17-2010, 08:37 PM
ArmyDawg's Avatar
Newbie
Thread Starter
Join Date: Apr 2010
Posts: 6
Likes: 0
Received 0 Likes on 0 Posts
Default

Ran the fuel pressure up with the computer.

Pressure did not drop off.

---AutoMerged DoublePost---

Ned to get one.
 

Last edited by ArmyDawg; 04-17-2010 at 08:37 PM. Reason: Automerged Doublepost
  #8  
Old 04-17-2010, 08:37 PM
12vcummins96's Avatar
Administrator

Join Date: Aug 2009
Location: Pearland Tx
Posts: 5,765
Received 340 Likes on 273 Posts
Default

the lift pump pressure or cp3 pressure
 
  #9  
Old 04-17-2010, 08:53 PM
ArmyDawg's Avatar
Newbie
Thread Starter
Join Date: Apr 2010
Posts: 6
Likes: 0
Received 0 Likes on 0 Posts
Default

Don't know which pressure they were showing me at the GMC shop on the computer.

My curosity is why does the truck start great in the morning when the engine is cold and just crank over when it is hot?
 
  #10  
Old 04-17-2010, 09:01 PM
12vcummins96's Avatar
Administrator

Join Date: Aug 2009
Location: Pearland Tx
Posts: 5,765
Received 340 Likes on 273 Posts
Default

i had a ford idi 7.3 that when it was cold would fire right up then when it got hot it would not start unless i used some kind of starting agent
when your wife ran it out of fuel your injector pump was ran dry no lube means alot of wear real quick and i think that is your issue
 

Thread Tools
Search this Thread
Quick Reply: 2003 Duramax will not start engine is hot without prime.



All times are GMT -5. The time now is 11:35 AM.