This is a 99 5.3 Z71

I am having rough idle issues on startup, once the truck warms up it idles fine. Also, the 1-2 shift will blast you sometimes. It's not every 1-2 shift but probably 50% of the time it is rough.

From what information I have gathered searching around on this site from people with the same issues it seems as though the intake / intake gaskets might be my culprit. So, can anyone verify this is most likely the problem?

Also, if I am going to pull the intake, is there another intake that it could be beneficial to do an intake swap while I have everything apart?

Any help is greatly appreciated!

 

do you have a K&N or any after-market air filter?

 

have you cleaned the throttle body, maf? had the injectors cleaned?

 

Exact same thing happened on my 97 Burban, they replaced the converter and it fixed it. I guess it was locked during the shift sometimes? Maybe something to look into.

 

Everything on the truck is stock.

 

I was going to clean the TB and MAF this weekend, I ran some injector cleaner through it but it did nothing.

I probably need to add that this only happens on the first start of the day. After my initial drive to work it runs and idles fine the rest of the day. So, that leads me to believe that once it gets colder this problem is only going to get worse.

 

idle air control? maybe good on the hot side but not the cold side.

 

mine will miss and shake like it has a small cam in it for about 10 seconds on a bone cold start(going to work in the morning)

 

It might be the Fuel Pressure Regulator......