Engine puff when I turn it off (sometimes) - 08 Yukon Denali

[plush]

When I shut down, my engine puffs, or pops, sometimes. Reminds me when i had my 70 Cutlass ans it had some issues with the carb. What would be causing this? Just a lot of strange stuff going on. Also, when I hit the gas (to the floor) at first it kind of whoomp (reminds me of old old vacuum leak). Guy at Autozone where I was checking my alt said that is normal for my CAI (K&N, AEM, etc). I found this strange.


Any guidance or help.

 

[04ctd]

how much oil is on your K&N?

the IAC has a small passage, and oil or stuff getting in there will make it idle bad and act strange, but never heard of either of your problems.

high mileage vehicles need the IAC passages cleaned anyways, so might try cleaning the throttle body & see what happens

hth?

 

[plush]

how much oil is on your K&N?

the IAC has a small passage, and oil or stuff getting in there will make it idle bad and act strange, but never heard of either of your problems.

high mileage vehicles need the IAC passages cleaned anyways, so might try cleaning the throttle body & see what happens

hth?

Actually, I have the AEM, he just referenced it as a K&N. I have 39k on it, but only 1k on the AEM.

 

[Gzes]

Hi did you take it to a shady mechanicor buy it used? Might be a bad mess with a bootleg redneck quick fix but might be something that could continue and turn out to b something major that will be very bad for a truck that new. Try flushing the carb also and use some fuel injector cleaners might be that they are dirty. Do you have factory warranty? If so take it to them and see what they can undercover and possibly fix.

 

[plush]

um, stupid question here, where is the carb? I cleaned the throttle body and bought some injector cleaner. Yes, it has a 3 month 3,000 mile warranty but I don't know what it is and last time I had it in to get something check they ran it an no codes came up.

 

[ChevyGuy]

The CAI should have no impact on what you are experiencing, unless it was over oiled when installed and the MAF is now dirty.

 

[plush]

The CAI should have no impact on what you are experiencing, unless it was over oiled when installed and the MAF is now dirty.

Nope, These AEM are not oiled, I'll get some MAF cleaner to see if that helps.

 

[stevek]

um, stupid question here, where is the carb? I cleaned the throttle body and bought some injector cleaner. Yes, it has a 3 month 3,000 mile warranty but I don't know what it is and last time I had it in to get something check they ran it an no codes came up.

Carbs are only on naturally aspirated motors (not fuel injected like 99.9% of today's cars)

 

[plush]

Carbs are only on naturally aspirated motors (not fuel injected like 99.9% of today's cars)

That is what I thought, but the guy said 'flush the carb'.

Also, the whoomp is the throttle body flapper (whatever it is called).

And, something I did not know, when I remove my tube going into the throttle body, the truck dies. Is this normal?

 

[ezdaar]

The carb is under your nose... Flush it with plenty of beer. That useually works for me...