Forgive me, already tried searching but posting from a phone.

I just changed the plugs off my 01 after a plug fouled up. I also cleaned the IAC. The car runs smooth but my AFR is hovering around 12.5-13 at idle. It normally sits right at 14.7. I originally thought it was my gauge since it read rich while coasting in gear, but appears to have gone back to normal. Could just changing the plugs (exact model, gap) and cleaning the IAC throw off my tune?! I don't see how but my next action is to change my gauge sensor of ensure its working.

I originally looked at why it fouled up but guessing cause all I did was putt it around town at 35mph for months might of. Compression is still around 215 for all cylinders (cold ap1 turbo with 157k)

At WOT AFR appears normal but cruising and idle is a little on the rich side.

If anyone got any ideas please let me know. I just posted here since this has changed during vaccum/NA operation.

Thanks for any ideas.

 

incomplete burn of the air fuel ratio will cause some issues like that. What plugs are you running, what gap ?. Any issues with the coils ?, or any misfire issues ?

 

Thanks for the response, but running NGK BKR8EIX at .30 and no misfires at red. Ive seen people gap them smaller but i am not misfiring at boost. Everything feels solid just the AFR. The exhaust does smell a little rich but nothing crazy.

Before this I had ignition misfire but it was due to the dead plug.

 

That plug is cold, and the gap is small when running in non-boost conditions. Running rich and not getting complete combustion. It may be fine and needed when you are running boost, but you will run rich in non-boost conditions with incomplete combustion of the air fuel ratio, especially at idle.

Tell us more about your engine setup and what you are doing to increase fuel delivery ? . Fouled plugs from running rich is very common, particularly when you run colder plugs.

If you can run a larger gap that would probably help, run the largest gap you can without getting blow-out. Heat range 7 would work better in non-boost conditions to get better combustion but you may need heat range 8 for boost conditions depending on how much boost you are running. It's a trade-off.

 

FIC1000/Whinebro 255. I'll try to slowly increase the gap. I am only running 14.5psi so probably get away with it easily.

Thanks for the suggestion. I am still just excited my crap idles after clutching in instead of wanting to die lol.

 

My replies were mainly based on the fact that you said the changes occurred as soon as you changed plugs. But see if you can tune out some of the fuel at idle, 14.7 would be better, 12.5 is too rich for idle and low throttle conditions.

What plugs and gaps were you running before this ?

 

The same that's why I am like wtf! All I did was replace plugs, same specs, and cleared my IAC.

I can't adjust the tune myself though. I am too stupid for that.

 

This may sound crazy, but did you keep the old plugs? Maybe, try re-installing them and see if the rich-issue goes away. At least, this will help rule-out plugs versus other problems.