My car idles at about 900rpms, and when I blip the throttle it hesitates then drops about 400-500 rpms and then goes up. If I try and hold the rpms at anything below 1500rpms it will do the rpm drop, then go to the desired rpm and fluctuate real bad or wont go to up at all. I believe my dashpot needs to be replaced, but will a bad dashpot cause this symptom? If I slowly hit the gas it will always do the drop in rpms making me look like a jackass in traffic becasue I have to take it to 2 grand before I let the clutch out at all so it wont do a sudden drop and stall on me. I guess what Im asking is will a new dashpot cause fix my proeblem? If not what could be wrong? I still get full boost when I get into it. My mods are a rebuilt engine w/ 3mm apex seals with a small street port, pettit SMIC, racing beat exhaust, 3 inch downpipe w/ catback, K&N intakes, pulley's, and PFC.

 

Bump

 

https://www.rx7club.com/3rd-gen-archives-73/dashpot-uim-180123/

looks like a cheap part so why not just replace it and go from there.

 

im having the same issue.. hold idle at 2300ish and it will drop 300rpm or so then back up, then do it again. pretty rythmical right?

 

sounds like the engine is bogging down for some reason... check fuel delivery, air filter... see if theres an obstruction in the piping from the intake to the throttle body