Engine hesitates

[El_Callao]

My go to for how this sounds is spraying to look for manifold vacuum leak.
any other recent work? Ac performing similarly to how it has been?
Slip the ac belt off and see if the tensioner pulley sounds rough.
From there I’d want a scanner of some sort, make sure there’s no codes stored, where the fuel trims are when it’s acting up, and sometimes you can see a response spraying the intake that you can’t hear

What spray should I spray ?& no other work and I’ve already tried scanning and nothing popped up

 

[ks03]

I like using carb / throttle body cleaner, as long as it says extremely flammable, doesn’t puddle much, and doesn’t leave anything behind, I’m not too picky about what kinda aerosol

 

[ks03]

Can you see your fuel trims?

 

[El_Callao]

I like using carb / throttle body cleaner, as long as it says extremely flammable, doesn’t puddle much, and doesn’t leave anything behind, I’m not too picky about what kinda aerosol

Would you be able to hear it ? And where do I spray it ? &

 

[El_Callao]

Can you see your fuel trims?

What is fuel trims?

 

[OR VietVet]

Sounds like you can have a/c on while driving but shut off while idling. Till you get it figured out.

What @ks03 said about vacuum leaks. I forgot about checking that. A bad enough vacuum leak at idle can cause shakes but when increase speed you will not feel it.

 

[OR VietVet]

If the leak is big enough, you will hear it when idling and hood open. If not, you can use the sprays suggested but a spray bottle of water works too.

 

[OR VietVet]

Would you be able to hear it ? And where do I spray it ? &

See my out of order post above

 

[ks03]

Would you be able to hear it ? And where do I spray it ? &

As far as hearing it directly, you might, but I think it can be hard to decipher a vacuum leak where you don’t want it vs air normally going through the throttle body.
The indirect way of hearing that I usually think of, is that if you spray somewhere there is a vacuum leak the engine may smooth out, or rev higher or lower

where to spray. Area of focus more common on these engines are the intake manifold gaskets. Otherwise anywhere that has vacuum. Around the throttle body, with the intake hose attached, pcv hose, fuel pressure regulator hose, brake booster hose, brake booster, evap solenoiid…I’m sure there’s more, and any related connections.

thinking this sounds new to you, water, like @PNW VietVet suggested, is safer to play with. The reaction to the engine pulling it in might just be reversed, revs slowing down or stalling vs raving up or smoothing out. If you use carb cleaner, only spray a few seconds at a time, let any puddle evaporate before spraying more…Hitting a hot exhaust or loose /bad plug wire can cause it to ignite, so try to limit how much fuel youre spraying at a time so that if it was to ignite it would almost immediately self extinguish.

 

[ks03]

What is fuel trims?

In your scanners data there might be a stft, ltft, or b1stft….and the values are in a percentage + or -. So short term fuel trim, long term fuel trim, then B1 would be bank 1, b2 bank 2. So if everything is 0% it’s running exactly how the pcm hopes. + - 5% combined short and long term I wouldn’t get too worried about, and for you symptoms I would be looking for more than 10%. If you have a vacuum leak, your engine would be running lean, to compensate it will add fuel. So if all the values are positive, like +15% at idle, that would confirm my belief that you’re running lean, where I’d go looking for a vacuum leak. Say you had a bad manifold gasket and you sprayed carb cleaner at it on the right side of the vehicle, a second or 3 later you might see the b2stft suddenly go -% because he pcm is taking away fuel. A few seconds after you stop spraying it would return to where it was.

….and just because it’s lean isn’t necessarily a vacuum leak, could be low fuel pressure, or fuel quality, ethanol content just to name a few