pnbell

So I have had this Rough idle (and very slight misfire sometimes) especially when the engine is cold...

This weekend I Replace all the Vacuum Lines, Cleaned the ISV, Installed New AOS, Installed a New End Cap O-Ring in the Upper Balance Shaft Housing, and Clean a bunch of ground connections...

Start her up,,,, and Rough Idle!

Decided to replace sparkplugs ( I had Autolite Xtreme Performance Iridium Spark Plug with the pointy tip) and bought some Bosch Platinums.. When installing the Bosch Plugs I notice the Gap was tiny when compared to the plugs i was removing...

So i checked the gap on both plugs, and the plugs I was removing were like .045!! (should be like .028-.032)

Anyway install the New Plugs with the Correct Gap; Car runs So much Better and the Idle is So Much Smoother!

A Simple Check for Rough Idle/Misfire = Check Your Spark Plugs!!

BlackOp

I may be wrong but I dont think you a supposed to use the Platinum series plugs...

pnbell

Yea, you might be on to something... I did notice that at first my car idle and ran great... But last night i went out for dinner, and it seemed to idle rough again...

I will pull the plugs and check them out... and probably pick up some Coppers

BlackOp

Have you replaced your fuel filter...also the FPR can be a culprit.

pnbell

Yea, Fuel Filter is brand new.

If the FPR failed, It seems like the car would run better when cold; I read that when the FPR fails; the diaphragm inside cracks, and actually allows gas to get into the vacuum lines; this causes the car to run rich. Much Like a Choke on a carburetor; So when its cold the engine would start easy, but when warm it would be too rich...

Thanks for the input, i will update this post with my findings!

I am wondering if maybe my i am getting too much oil in the cylinders and causing the plugs to foul... I will pull the new plugs out, and look at them,.. But based on what i read i think i will pickup some Copper Plugs either way... A lot of complaints about Platinums in our cars (your were right)