no top end power

[Mark A]

On my 01' truck has turned into a dog. It wont get out of its own way. I've changed the fuel filter and it made no difference. Then i unplugged the batteries and let it reset and it seemed to help. Now its doing it again, the SES light kept coming on so i hooked it up to AUTOTAP and we pulled the codes and it was the mass air sensor. We cleared the code but i dont know why some days it will be strong and the day be a dog. I also pulled the MAF sensor out today and cleaned it but didnt help. It also seems like the pilot injection isnt shutting off either cause i dont hear the motor start making noise, could this be a problem since it shuts off where the truck isnt making power? Just wondering if anyone else has had this happen.
Thanks for the info..

[Kennedy]

Look for an obstruction or air leak in the intake side. The leak would be AFTER the MAF sensor.

How many g/s does the MAF show at idle, AND have you messed with the air box?

Also bulletin GM TSB# 01-06-04-050 addresses the early air box and the updated one for '02.

[Mark A]

I have the K&N air intake on it. I checked the hose clamps and everything was tight, this was one of the first things i did. Is there any connection between the MAF and the pilot injection? Seems today after running down the interstate a while it is running better and you can hear the pilot injection cutting off at 2500-2600 rpms. Also what should the MAF readings be? I'll be hooking it back up to the laptop this afternoon and record everything from idle to wideopen runs.

[Kennedy]

From where I stand, I'd say put the stock box back in. If you are hung up on having a sieve for an air filter, drop in a K&N cartridge.

The DMAX programmiong is tied closely to the MAF sensor, and the design of the OE box lid. If the air can find a better path that does not register on the MAF sensor, it will, and that's going to hurt you. I altered my lid early on and learned the hard way.

In time, there may be some new developments, but for now, Id stick with the lid that came with it, and maybe try to shut out underhood air in favor of fresh, ouside air.

IIRC, Volant has yet to come to market with a kit, and Im pretty certain this is why...

[6600 Duramax]

I have also noticed that my pilot injectors do not disengage all the time. But I so notice if I push to 3000 rpm+ it does, is this normal. Also I have added the Amsoil Air Filter. Could there be oil on the MAF sensor that is causing a probelm. I oiled the filter when new (didnt seem to be much oil in it), but did not soak it. Also had a little piece of foam sticking out side, but screw was tight and I was in a hurry so left it that way. Could this be causing a problem? Is the pilot injector supose to shut off ALL the time above 2500 or just when pushed?

Thanks Guys

[Mark A]

i was out earlier and noticed the same thing with mine when i was messing with it. The pilot injectors were not shutting off till 3000 rpms.

Duramax 6600,
Is you truck doing the same as mine is?

[Kennedy]

There is no real precise cutoff for the pilot injection. Just because the sound does not intensify does not necessarily mean you are missing anything. We never hear it kick out on the dyno.

I also seldom hear it with a box on, but stock, I sometimes do.

Guess what Im trying to say is: Just because you dont hear it, doesnt mean it is not occurring AND just because it intensifies in noise does not mean you gain power...

[6600 Duramax]

Mark A

I wouldn't say it is doing the exact same thing. But I have noticed the pilot injector not turning off, but Kennedy is probably correct. Since I dont have a Dyno or G-Tech it is hard to say if it has more power one day or not.

But I will say this there are days when I think this thing is doggy, BUT the other day when I was thinking this I had a buddy with me and he said he was F*&%&G PI*##D his 99 K2500 350 didnt feel this strong. So I have come to the conclusion that I am just getting use to the POWER. Dont know if I should accept this or just get the JUICE!!!!!!! (Maybe soon)

Could the MAF be dirty???

Thanks

[Wally]

If your running K&N there is probably two things happening to you. The MAF is dirty and oily!
Since you say that it has thrown codes relating to the MAF I don't think you're imagining things. It's the real deal. I don't know the specifics for cleaning the MAF. I'm sure someone here does.
Clean it, ditch the oiled porch screen wire you have for a filter and voila, you should be good as new.

[SoMnDMAX]

Something else to check....

Has the carpet or floormat bunched up under the loud pedal?

If so, you will not be able to get full throttle.....