secondary throttle butterfly

Jts · Post by **Jts** » Thu Nov 30, 2006 2:34 am

well fuel filter is clean, I dont think i have a lack of fuel issue (carb level stays constant no matter how much i rev it. I decided to try unplugging the o2 sensor and see if it made a difference. I was surprised to find that it ran alot better with it unplugged. I will get another sensor at the jy to test if it is the cause of the stumble. It seems like i have a lean stumble, and ive read its possible for a faulty o2 sensor to lean it out (on this forum), I'm curious to see if this is the cause of the stumble. All the things ive done (repaired vac advance, egr, egr modulator, new vac hoses) have improved the performance of the car, but the stumble has not changed where in the rpm and throttle angle range in the slightest.

takza · Post by **takza** » Thu Nov 30, 2006 4:31 am

I've seen Corollas just stop due to a clogged fuel filter.

Seems like the issue might be in the carb and due to the transition to opening the secondaries...think this uses vac...maybe a diaphram?

Jts · Post by **Jts** » Thu Nov 30, 2006 2:23 pm

i thought this might be teh case takza, so i took off the vac secondary can. It held vacuum just fine. It gets vac through a port directly in the carb, so i cant apply vacuum to test it, I believe that the system is working alright, because it has decent power when floored. My butt dyno says that while its slow, its prolly where its supposed to be. a non opening seconday on the carb should kill high end power considerably, but this seems to be fine. I'm guessing o2 sensor since thats supposed to work in the midrang (where the problem lies) and it worked better when unplugged. Perhaps its stuck on a lean position, while unplugging sends it to limp mode, but still lean position. Im hoping a new one will richen up the mixture.