4xcrazy
3/4 ton status
Been fighting this idle issue in this Avalanche for awhile now.
Does a random type of stumble, and even the normal idle just seems to have a shake I used to call "the Chevy shake" those were the old engine designs though, have they not figured out how to get them running smoothly? Or is there some seriously wrong with this thing?
Recent problems started getting worse, and even more so after I cleaned the MAF sensor the other day. While under throttle, usually, if you tried to roll up the windows, the engine would hard stumble, like turning the key on and off real fast. After attempting a cleaning of the MAF, it started getting worse to where the engine would just flat out die when you put it in park and the auto door locks would unlock the doors. Or if you hit the window switches, just immediately kill the engine.
It always brought up a CEL for the MAF low voltage reading or flow. So I just changed it earlier. Now it seems to be a bit sluggish under throttle, the surging while under throttle with windows working isn't present any longer though. Hasn't thrown any codes as of yet.
Engine still randomly stumbles while idling, last time I heard it is when the electric fans turned OFF, engine started stumbling like it had a hot cam in it, at the same time I could hear something working trying to counteract this, maybe the electronic throttle body, unsure.
Fairly new battery, brand new alternator 2 months ago, just checked all cable connections before installing the MAF, ran it around the block without the K&N filter element to see if that was restricting air flow.
Something is not happy, it seems to surge a slight bit while under hard throttle at times, again, random. Some times it'll be sluggish getting going, but once going it pulls decent, others it's half way sluggish and has a slight power surge as it's pulling, similar to what a plugged fuel filter would cause or a pump losing power.
I just checked the fuel pressure a couple of months back and it was up at the 60 psi mark if I remember, I know it was up pretty high. I suppose I could check it again. This fuel system does have over 145k miles on it. Heck maybe it's about due for a fuel pump assembly...
Any ideas?
I was quoted $125 for the software update, he mentioned the surging idle problems that it's supposed to help cure, then again he could have just been saying that to get me to do it. Anyone have any first hand experience with this software update on the newer trucks?
Quoted $89 just to put it on the diagnostic computer..
Does a random type of stumble, and even the normal idle just seems to have a shake I used to call "the Chevy shake" those were the old engine designs though, have they not figured out how to get them running smoothly? Or is there some seriously wrong with this thing?
Recent problems started getting worse, and even more so after I cleaned the MAF sensor the other day. While under throttle, usually, if you tried to roll up the windows, the engine would hard stumble, like turning the key on and off real fast. After attempting a cleaning of the MAF, it started getting worse to where the engine would just flat out die when you put it in park and the auto door locks would unlock the doors. Or if you hit the window switches, just immediately kill the engine.
It always brought up a CEL for the MAF low voltage reading or flow. So I just changed it earlier. Now it seems to be a bit sluggish under throttle, the surging while under throttle with windows working isn't present any longer though. Hasn't thrown any codes as of yet.
Engine still randomly stumbles while idling, last time I heard it is when the electric fans turned OFF, engine started stumbling like it had a hot cam in it, at the same time I could hear something working trying to counteract this, maybe the electronic throttle body, unsure.
Fairly new battery, brand new alternator 2 months ago, just checked all cable connections before installing the MAF, ran it around the block without the K&N filter element to see if that was restricting air flow.
Something is not happy, it seems to surge a slight bit while under hard throttle at times, again, random. Some times it'll be sluggish getting going, but once going it pulls decent, others it's half way sluggish and has a slight power surge as it's pulling, similar to what a plugged fuel filter would cause or a pump losing power.
I just checked the fuel pressure a couple of months back and it was up at the 60 psi mark if I remember, I know it was up pretty high. I suppose I could check it again. This fuel system does have over 145k miles on it. Heck maybe it's about due for a fuel pump assembly...
Any ideas?
I was quoted $125 for the software update, he mentioned the surging idle problems that it's supposed to help cure, then again he could have just been saying that to get me to do it. Anyone have any first hand experience with this software update on the newer trucks?
Quoted $89 just to put it on the diagnostic computer..
