hey guys( and gals) i need some help. my car idles unsually high. i got the tps adjusted right with the voltage on 1k but it still idles at 1.5k and sometimes it drop below 750 rpms and runs pretty rough.i did play with idle screw, but that wasnt much help. i was thinking maybe my timing is off, but how would i check it if it is idling really high? does anyone have any ideas on how to fix this problem? thank you in advance for your input. ohh yeah i have a 1986 mazda rx7 with intake and exhaust.

 

what exhaust, cat back?

It sounds maybe like a cloged cat.

Tim

 

my 86 with only a K&N filter and a lil bitt of duct work has a high idle. it is almost always at 2grand and some times drops as low as 1500-1400 but other than that in neutral or with the cluth in it stays up there!?
now i didnt do any exhaust work, but i was told when i bought it that the exhaust had been replaced from the y back. also i have noticed a light "poping" from the tail while it idles. could my cats/cat be causing this??

 

I will be replacing the complete exhaust, headers to the tip, with the racing beat system but could a clogged cat really cause my rpm's to drop sometimes? could the ignition timing cause this?