Normally I'm not one to complain about a "free-revving" engine, lol...until it does it on its own.

So the last few weeks my car has had this little problem, but its getting worse. Sometimes the car will idle just fine, but then (while idling at a stop) the revs will start to climb up to 2500-3100 rpms and it will just sit there at that rpm. I have to partially engage the clutch to slow the engine. Also while shifting, rather than revs dropping off between shifts when I put the clutch in and shift at say 4000 rpms it will rev up by itself (my foot IS off the accelerator) to 4500-4800 rpms then once I engage the clutch again it will drop down to the proper rev speed.
WFT is going on? Has anyone else experienced this problem. I have an OER sidedraft carb (like mikuni or weber). It has a lightened steel flywheel (so you'd think that revs would drop off quicker, lol) and is attached to a racing beat 'stage 2' street/strip clutch, and a 13b gsl-se tranny.

Anyone have any ideas? I think maybe the butterflies are staying open for some reason (maybe a loose nut on the linkage?) Any help would be beneficial. Thank you in advance.

 

how is your return spring

 

non-existent...another one of the many parts that should have come with it from a certain vendor on this site who shall remain nameless...but, it seems to snap shut by itself anyways...so who knows. Remember I've been running this carb for the last 5 months and just recently started having this problem.

 

hmmmmm, i also have an OER and the same problem but with a return spring, the idle would keep climbing lil' by lil' as i drove it, up till bout 2400 rpm, i could get it to go back to a normal idle by physically turning the throttle back by hand just a little. i think i just need a stiffer return springthan what it came with. I had to make my own throttle cable braket and then mounted my return sping on the underside. BTW how does yours run, mine's a little hesitant at cruising speeds but great at WOT

 

yeah, I get a hesitation if I jump on it from a cruise...rx7doc tuned it pretty well so it barely hesitates anymore. I had to make my own bracket too, I take it yours came from a certain shack...

 

yes sir

 

I'm going to try tightening up the nut on the throttle bracket arm in the morning and see if that helps, it may be loose. IIRC last time I tightened it, it helped out...hopefully its just the same thing...If it solves it, I'll just put some loctite on it this time.

 

If your idle is set to high it may act like it has a normal idle, then all of a sudden with any jiggle in throttle jump up to a few 1000 in rpms because the idle is starting to run into normal throttle. (sounds stupid but I have had it happen on a carb before)