Problem: car was running ok, but at stoplights and stop and go the rpm's would "hunt" around, bounce up and down a lot. Started to annoy me to the point where I wanted to try and fix it.
First attempt:
I read up that normally the Maf or IACV is the reason for this. So I first tried cleaning the MAF, and little sensor inside the airbox using Pyroil Parts Cleaner. After putting it all back together the car ran exactly the same.
Second attempt:
I took the iacv off, took it all apart and cleaned everything using the same Pyroil Parts Cleaner and also Simple Green. The housing, springs etc. Then dried everything off and put it back on the car. The car idled, but then slowly went to running rough and idling weird. Sounding like it was misfiring. Note, I did notice that the inside of the intake manifold was just as dirty as the IACV before I cleaned it, could this be a reason for it running rough? Would cleaning the manifold out help anything?
Third Attempt:
Replaced old spark plugs and wires, as they were old. Car still ran the same, idling all over, bouncing idle and running rough- Drives smooth once moving but just the idle is bad.
Fourth Attempt:
Replaced the IACV with a brand new one, and again- the car still runs rough and idles weird, misfiring it sounds like to me.
When I start it when its cold it will idle fine, then I go drive it around the block a couple times and get to a idle again and it goes really rough and the idle drops super low and will stall if I let it go long enough.
Fifth attempt:
The car also sometimes feels like it has random cut outs of fuel when accelerating, so I replaced the fuel filter and fuel pump. Car runs a bit better but still the same idling issue and running rough/rough idle.
My end thoughts:
Could I narrow it down to be the MAF/ airbox sensor that is the problem?
