Archived Hard Starting When Winter Arrives

[WileyCoyote]

My 2001 HO 6 speed has again developed hard starting. Last year when this happened--November--I changed the lift pump and after a while, not right away, the problem seemed to get better. I blamed the Shell additive I had just begun using for something like "vapor lock" in the VP 44 after heat soak.



Now here we are again with exactly the same problem a year later. The truck sometimes will absolutely not want to start until the lift pump runs for a long time. I assume that the winter blend diesel has arrived here--Southern New Mexico--but our weather is not cold enough to keep this from happening.



I have a copy of a service bulletin that calls for reprogramming of the ECM to help eliminate this problem. Have any of the rest of you had this problem? Does the reprogramming help or is there some other solution?



Thanks,



Harry

 

[WadePatton]

The "hard start" flash causes the lift pump to run for a much shorter time. It was piggy-backed onto a re-flash I had done for a different problem.



Instead of running for several seconds at Key On, now the LP only runs for about 1/2 second. No change on starting, but I didn't have a problem.

 

[Big Jon]

Grid Heater?

Harry,



First, does it make any difference if you've plugged the block heater in overnight?



I don't know how "cold" is cold down your way, but if you're really talking close to zero and below, the grid heater might be the problem. If it's not heating up, you're relying strictly on cranking to build up the heat necessary to get a cylinder to light. An easy (but not fool-proof) way to see if it is working is to watch your voltmeter gauge when the "Wait to Start" light is on. If it's not drawn down to about 8 volts during that time, it's probably not working.



I haven't had the hard-start reflash done, but have had one time where I had start the truck after a prolonged cold soak at around 18 degrees F (no where to plug the block heater in) and it fired right up.



Good luck,



Jon

 

[WileyCoyote]

Hard Starts

Big Jon--It has gotten clear down to 35 here so far this winter. But the truck has more difficulty starting hot, not cold.



You can drive the truck, let it sit for an hour, get in and not have it start until after several tries.



The problem is almost exactly on the same date as last year, so I suspect light component fuel.



Also, the SB describes the problem exactly.





Harry

 

[MidwestMotorman]

Hard starts

I would suspect an IAT sensor or a dirty fuel filter. Cold diesel does not like dirty filters, and the IAT would mess up computer.



35* is cold????? I have started mine in -35* weather, both warmed up and cold. Never a cranking or start problem. I will admit it does take two revolutions to start at -35* though



I would suspect a sensor or possibly an ECM problem. Reflash needed?

 

[JR2]

I believe the TSB below while solve all your problems...



18-015-00A



All Driveability enhancements for winter fuel use and for hard starts.

This bulletin applies to vehicles equipped with a 5. 9L-24V diesel engine built between engine serial numbers 56419738 to 56798357, with a date of manufacture of December 16, 1997 to November 15, 2000.



The customer may complain of poor driveability when winter fuel is used to power the engine. Or, the customer may complain of a hard or no-start condition, while the engine is at normal operating temperatures, when using any type of good quality diesel fuel. The poor driveability condition may occur only when either straight #1 diesel fuel is used or when other special cold climate winter blend fuels are in use.



The no-start or long engine crank condition may occur when attempting to restart the engine while the temperature of the engine is till close to its normal operating temperature. This hard hot restart condition may be experienced in all ambient climates, but may be more of a concern in warmer ambient climates. The repair involves selectively erasing and reprogramming the Cummins CM551 Engine Control Module (ECM) with new software.





I had this TSB done for another problem (stalling when I put truck in gear) and can report no adverse effects on my truck.





JR2