Terrible surging during acceleration

[jcilufo]

A friend of mine has a 2500HD LS 4x4 and during acceleration he gets really bad surging right at 48 mph. He took it in and they told him they all do that. Has anyone heard of this?

[CMNTMXR81]

No.  The dealer told you this was normal?  

 

You: My truck is on fire

Dealer: This is normal.

 

Unbelievable!

 

Does it set the SES light?  Without scanning it, it could be a fuel related issue or dare I even venture a transmission/torque converter lockup issue.

[jcilufo]

He said the SES light does come on and code says "random misfire"

[Shaners]

If the SES light comes on then there is something wrong!!!

 

You didn't mention what motor/tranny/rear gears are in this truck,  But if the surging or stumble were to happen at low RPM with the torque converter locked up, I could see it being a random missfire.

 

There may be some updates to the computer on his truck.  Have the dealer run the VIN and he should be able to see if he has all the recent computer updates.

[jcilufo]

He has the 6.0 with the 4L80E trans and the 4.10 rear. He said the dealer checked for the computer updates.

[CMNTMXR81]

How many misfires?  How many cylinders misfiring?

 

However, lately I've been on a fuel side mantra pertaining to misfires.  

 

What fuel does he use?

[Shaners]

He has the 6.0 with the 4L80E trans and the 4.10 rear. He said the dealer checked for the computer updates.

My 2001 6.0L doesn't do that, I only know of one other truck that has a little hesitation in it and that is my friends new 2002 and he says it occurs under load at about 55 mph when going up a hill.  But it isn't bad enough to really bother him....

[JimWilson]

The SES posts an error and this genius says nothings wrong?! ??? Is there a *real* dealer somewhere near him that he can take the truck too instead?

[Guest]

There may be some updates to the computer on his truck.  Have the dealer run the VIN and he should be able to see if he has all the recent computer updates.

??? That kinda caught my eye so I thought Id ask...Do dealers constantly recieve updates to program into our vehicles when we take them in for service???

[CMNTMXR81]

Yes.  All GM dealers are online with the GM tech center and have access to these updates.  Some already have them downloaded due to previous customers with the same problem having already requested an update.  Then sometimes, you may be the first and they have to download it.

 

It goes by VIN#.  I checked mine in the SI2000 system and my VIN didn't have any updates.   But that didn't check for TSB's or campaigns outstanding on it.