Help! Why is my engine doing this?

Now that you have a CEL check the code/codes.

 

Never mind now it's surging again. Will check codes

 

I’ll guess crank sensor.

 

Throttle position sensor?

 

The fact that it smoothed out as he tipped in to the throttle to 2k rpm lines up with vacuum leak as there is a sharp drop of vacuum once the throttle body opens off idle. I suspect a cps would be rough at any rpm.

 

Any recent work done ?or was this out of the blue just started out of nowhere.

 

Reminds me of a old honda civic idle surge. If there was a big enough vacuum leak the engine idle would surge and the computer would knock it down repeatedly like that.

 

No recent work done besides new pads and rotors. Just a pleasant Thursday morning surprise after a hard work week and I just wanted to go surf.

 

Did OBD read anything? for the check engine light

 

Subbed.

 

Stage 3 cams?

 

Do you top off your tank a lot? Gas cap on and tight? At least now it has thrown a code.

 

I remember those. The "vacuum leak" was usually that coolant-controlled "fast idle" valve on the back of the intake that would stick wide open..

It would idle way up, the computer would see rpms going up but closed throttle for some reason, so it would cut fuel..

Up.. down.. up.. down.. up .. down..

Very strange indeed.

 

.

 

OP, surely you have read the codes by now?

 

Maybe he had something strange pop up like a job?

 

No, if you read the OP’s post you would have read he was going surfing till the idle issue!

 

Nice chop

 

Lol, didn't see that part. Good for him! I go fishing when I don't know what the fuck to do.

 

2019 and some 2020 had a fuel pump recall. Check your vin... You could be one of the folks who is due a new fuel pump under the recall