hey guys, gettin really frustrated. sittin @ a light,(auto trans.) idleing fine then the idle stumbles real quick. never dies. takes off ok, doesn't do it in park. things already done: cleaned air filter, maf, checked those red & green vacuum lines, plug wires were old so i replaced those.(motorcrafts) put autolite plugs in earlier this year. haven't looked at them recently though. replaced iac. WHAT am i missing?? looked for coolant leaking into spark plug hole but didn't see anything. please help!

 

my mach did that, until i put NGK plugs in it.... not saying it will for sure save yours but definitly eliminated my stumble...

 

This is just a shot in the dark, but have you tried replacing your fuel filter? Maybe one of your injectorsis going bad, have you checked those? Have you had your car tuned after your mods? It could be leaning out a little with the extra CFM's from that t/b & plenum combo. I could be totally wrong, but just my two cents.

 

been roughly 3 years or so since i replaced fuel filter.how do you check to see if injectors are going bad? nope, haven't had a tune. that stuff has been on there bout a year & a half. thanks for your input guys. oh, would egr valve have anything to do with this? never replaced before.

 

wow 3 years, id do it, you sholudl every 30k miles