I have a 2003 crewcab dually 2wd. It ran great for 45,000 miles. If you run it and don't shut it off it runs fine. If you shut it off for about 10 minutes and restart it it will quit when you get to 1500 RPM in drive. Bump it into neutral and it will restart fine. 1500 RPM in drive and it will quit again. It will restart just fine. Run the RPM's up to 2000 in park it will shut down again. I have had a VDR installed twice by the Chevrolet dealer and they are saying the RPM is spiking to 7000. I say that can 't happen. They think it is electrical. I have showed them and told them when this occurs to make the engine run again all you have to do is open the water drain on the bottom of the fuel filter. You can hear it sucking air then fuel runs out. close the water drain and the truck will run fine for 3 or 4 days. any help will be greatly appreciated.

If they think the RPM's are hitting 7000, but the engine is obviously not turning that fast (you would know it if it were!!), then the crank reluctor wheel may be loose or bent.


Your last 3 sentences make it sound like a restriction in the fuel system between the filter and the tank. Maybe foreign material in the tank plugging the inlet screen.

Thanks for the reply. The dealer checked the reluctor wheel yesterday and it was ok. they also have replaced the PCM, FICM, and the crank trigger sensor. they have dropped the fuel tank cleaned it and the lines but it did not help. they are going the put stiffer fuel lines on it from the fuel filter to the FICM tomorrow and see if that doesn't help. will keep you posted on the results.

found the problem!!! It was the reluctor wheel. the dealer removed the crank trigger sensor and the housing and you can move the reluctor 1/2 in. up and down. they said that will really throw it out of time. nobody stocks a reluctor it is a ship direct part only. it will be shipped within 48 hrs. of the order. so no truck for about a week.

that is a growing issue Gm tech assist led me to one once.I guess the bolts come lose and the wheel has movement in it. good to hear they are fixing it. yes its ship direct and dont worey if it is lose this will fix it.

There is also a May04 GM Techlink article that covers this: Loose Crankshaft Reluctor (http://service.gm.com/gmtechlink/images/issues/may04/TLmay04e.html#story21)


"This information applies to 2001-2004 Chevrolet and GMC C/K and MD C 4/5 trucks equipped with the 6600 Duramax LB7 Diesel Engine with rough, unstable, incorrect idle speed or stall.


After completing the published diagnostics for an engine stall or misfire with no trouble found, and the data indicates intermittent high balance rates on random cylinders, check for a loose crankshaft reluctor.


To inspect the crank reluctor, remove the right inner fender, crank sensor, and crank sensor spacer. Use a blunt probe and try to move the reluctor clockwise or counter clockwise. If the crankshaft reluctor is found loose, repair by replacing the necessary parts and be sure to include the alignment pins."


http://www.dieselplace.com/forum/smileys/Geek.gif

Just read over the above Techlink and have a question.


Why are the LLY fuel injectors "on restriction" as mentioned in the Truck Issues-Fix It Right The First Time section?





Gary