My 2001 DMAX with 44k miles is acting funny. Sometimes it goes into a mode where the truck seems like it misses or the tranny slips a lot under a slight load. It does it in every gear and the SES light never comes on. It will act up a little and then finally clear up. Any suggestions on this problem? All fluids and filters were changed 2000 miles ago. I just got the truck Saturday http://www.dieselplace.com/forum/smileys/Confused.gif. Any help with a diagnosis is appreciated.


Justin

Does the air filter still duct into the inner wall of the fender?





Whenever there is trouble with a 2001, I try to start with air box and programming updates...

To be honest, I haven't even checked yet. I will today. It most likely is since an elderly gentleman owned my truck and never hardly touched it. Do you think that could be the problem? I will post after I check. The accelerator also seems like it takes more to get it going when this condition takes over. Yesterday it was bad, today it has been fine so far, except for the rough idle. I have an appointment for that update tomorrow.


Thanks!

http://www.kennedydiesel.com/dmaxairintake.html





Keep in mind, even IF the box was done, a lot of dealers doesn't mean that the programming updates have been applied...





Not likely the entire problem, and could be entirely unrelated, but good place to start!

Kennedy,


Thanks for the advice on the air filter. You mentioned in the Tech Tip that the dealer could do the reprogram or you could. I am assuming you would have to have the truck to do the reprogram? Don't mean to sound stupid, but I didn't know if there was another way. Do you think the problem could be fuel pump related???


Thanks,
Justin

I have had the same problem for quite some time, and was told today by the dealer that he couldn't find the problem or do anything about it. I would be very interested if the dealer fixes your problem, may not fix mine, but a start. I have raised the same questions and problems under the heading "loss of power"

After reading some old posts, I am beginning to think it is the rail pressure control valve. What do you think, Kennedy, or any one else with more information? Is this an easy fix by the dealer (easy to get to)?


Thanks,
Justin

Typically the RPCV will cause a lopey idle when on the way out.





I'd stop by the dealer and see about showing him the bulletin. Have a STOCK paper filter in the box, and no evidence of oiled type filter. Sucking the filter minder in will also be helpful. Politely suggest that you heard that the afformentioned bulletin MAY resolve this, and ask if he could apply as a warranty item.

Thanks Kennedy. Do you know the bulletin number on this?

My RPCV was getting so bad the truck almost stalled once or twice during an acceleration off the low rpm side of one of the lopes. But it never seemed to be an issue off idle.

Just got back from the dealer. What a round....First, he tells me that the number 5 injector is sticking wide open and causing all the problems. Next he recommends doing an injector flush before ruling a bad injector. Next he tries to give me the price. I stop him and say if the injector is causing problems, then it should be covered under the 5/100k warranty. He says no. He said the injectors are a regular maintainence item and are not part of the engine rotating assembly, which is covered. I said where does it say an injector flush is under regularly scheduled maintainence? He says in the owner's manual. I said, "Show me!" We go to my truck and can't find it in there anywhere (surprise, surprise)!


So I finally get him to call GM Tech Support and after 20 minutes on the phone, they tell him to fix it under warranty. I first asked the service manager 2 days ago if they have had any injector problems and he says, "No." "None." The manager checks with the parts dept. to order an injector, and low and behold, they are on "national backorder!" (Now I think he believes there are injector problems!)


Now I am waiting for an injector. Could be 2 days or 2 weeks, but I really don't think that is all my problem. I guess we will see!


Justin

sounds like an injector down or something in the fuel control.