First, we would like to thank all of you on this forum for all your expert advice. We find it very helpful in getting answers for our d-max's!

The truck in question is an 04 LLY D/A with 19k- This is a second time for a rough idle @ a stop. Seems to smoke a little when this happens. We run Stanadyne @ all times, and buy our fuel from the same place. Tried experessing this to the dealer, but get that blank look and the engine light question. When it happens it trips nothing on the dash-maintenance is followed by the book. These trucks seem to run the same all the time, so when you get this type of idle you notice it right away.

Thanks,

L.TIK Const Co.

Might try buying your fuel from another place. The worst fuel I ever had came from a Southern States station. They have heavy truck pumps and sell alot of fuel. Tried them twice, both times with bad results. The engine idled rough. the engine started new sounds I haden't heard before, and the milage dropped 1 to 1.5 mpg. I Don't go there anymore. Always do the easy things first. Good luck

REFLASH, REFLASH, REFLASH. Thats what it cures. Thats what you need.

What is a reflash, and who does this---the Stealer?


LT Const Co.

Yup! A dealer will need to do the reflash. My truck had a really bad idle @ 185 coolant temp sitting at stop lights. Finally after 3 trips to the dealer they reflashed the truck with the updated software. This was just yesterday. So far so good - no more rough idle.

If you have access to a tuner such as a Diablo Sport Predator you could look at the injector balance rates. In my case during the rough idle my #2 injector would spike up around 10.

It should only take them about 10 minutes to check if your truck needs updated and reflash it.

With my truck they checked the calibration rates of the injectors and they were fine. The problem was that they always checked them with the truck in park. If I had shifted to park during a "rough idle" situation it would clear up. I asked them to check with the truck in gear and the brake applied. Sure enough one of the injectors spiked. The software update is a ten minute repair and seems to correct this problem. At the time of my problem the fix wasn't yet available so GM had them replace all eight injectors. As soon as the fix was available I had them do the reflash anyways.