Hesitation and Surging

[sonic555u]

Well I fix my idle problem it turn out to be a vacuum leak and gave me all kinds of codes from bank 1 and 2 to missfiring on multiple cylinders. Well my friend who ported and polished my throtle body forgot to reinstall one of my vacuum hose in the front next to the throtle body so I cant really blame him since he hooked it up and he did it late at night around 2 in the morning. Well one night I was like I trust he did a good job but I am going to double check and make sure everything is good took of the engine cover and wala there it was in front of me a hose completely disconnected so I connect it, go turn on the truck and it sounded as beautiful as I remember and problem fixed.

 

[LateOnTheBrakes]

I'll have a look at the vacuum lines, but everything under my hood is in good condition and the hesitation is sporadic enough that I'd think it may be a small leak starting if a hose would be starting to rot.

 

[Torspd]

A lot of the hoses start getting cracks at the ends, around 100k. Could very likely be the cause as well. I have replaced all of mine with high quality silicone. Or braided rubber.

 

[xtrapsi]

I know this is digging up the dead, but did you ever find a fix for this?
My truck is still doing it and it is so annoying!

 

[jeybee2jz]

Same thing happened to me. Hesitating and surging at 1500 rpm. Turns out it was a vacuum leak.

 

[Torspd]

Only a few vacuum hoses on this engine, in stock form. Spray some silicone or carb cleaner around vacuum hoses and any areas that you hear a hissing. That will help you find it.

 

[xtrapsi]

Mine seems to have disappeared.
I changed the air filter, oil and the spark plugs and it is behaving now. Not sure if it was a vacuum hose or plugs but whatever...I'm glad it is gone.