Afternoon,

I have been trying to sort out my issue with my idle surging. It was doing it during both drive and park, but after putting a new cap and rotor on the distributor and cleaning the rust off the wheel, it now only surges while idle in park. What could be the possible cause?

I do have a video I can figure out how to link of it surging if needed.

 

We changed the oxygen censor and it's still doing it, but not as bad. It goes about 2 notches as opposed to 4 or more during a surge. It seems to only do it in park as well.

Fuel pressure was tested and it's within normal specks (12psi). So we ruled out the fuel pump.

 

Connect a scan tool, look at the data stream. I'd be especially interested in what the IAC is doing; the actual idle speed vs. commanded idle speed.

 

We decided to take it into the shop to see if they can figure it out. I'll hopefully know tomorrow since that's when it's being checked. If they do figure it out I'll let you know. I do know my friend messed with the idle so perhaps that messed it up and caused the surging; no idea.