Today my car developed a problem where it fluctuates from 1000-1300 while im waiting at a light.
It doesnt always do it and I noticed on my Air/fuel guage that it goes from super rich to almost stoich at the same time as the idle.
Im pissed at this car.
I noticed that my air filter blew out the bottom and was letting in dirt for god knows how long.
The car runs exactly the same as it always did.
I have only Type R Cams and springs and the type r cam gears with 4000 miles on them.
Anyone got any ideas?

 

Heeeeeeeeeeelp

 

u need a new fuel pressure regulator...or ur fuel pump is bad....if u dont mind putting **** in ur fuel tank...try Gumout by pennsoil...its a CONCENTRATED formula that cleans ur fuel line and injectors. i use it every other tank fill. keeps my idle smoothe and good on accelerating

 

check your fast idle valve, its on the intake manifold near your throttle boddy. there is a screw that sometimes gets backed out, and that can cause your idle to fluctuate. just a guess.

 

also check the IAC

 

in the end there s the O2 sensors

 

I guess ill try to change the fuel filter and clean the iac and throttle body.
If that dont work ill try the spark plugs.
What else should i check and how much is a fuel pressure regulator?
My motor only has 23,000 miles thats why i dont think its the fpr,The fuel filter on the other hand has been there for 180,000 miles

 

maybe a dirty or bad IAC sensor

 

180k on the fuel filter?..that sure tell s me something ..should change every 60k