So my car was perfect before I installed a new O2 sensor, drain the coolant to use OEM hose clamps to radiator hoses, and hooked up the hose to the air injection to the catalytic converter. Now at cold starts idle jumps from 1,200 to 1,500rpm, when warm it's fine but sometimes it jumps when going in and out of gear. Now the ACV acts like a blow off valve because when i rev the motor it makes a loud noise and spits out a gush of air (never did that before).
-Removed the hose from air pump to catalytic and no difference.

 

Sounds like the new OR is dodgy, is it a universal or a mazda oem? Sounds like the only thing of the changes you've recently carried out that could effect anything. Also maybe check your air screw under the throttle body.. and check for diagnosis codes, if you didnt cut the power when you disconnected the O2 it could have a stored code forcing it to run in safe mode.

 

- O2 sensor was a universal Bosch
-air screw is closed all the way
-I did disconnect the battery before all this
-No codes
Why does the ACV act funny now?

 

Can anyone help?
- I put the old o2 sensor and does the same thing.

 

Any ideas?

 

Reset ecu? Pull the battery, step on brake pedal for 30 second.

Not sure why the acv would be affected. The only thing you replaced was the o2? Touch anything else?

 

I reset the ecu and still the same thing
I replaced the o2 sensor, installed new oem hose clamps and hooked up the hose to the catalytic converter from the smog pump.

I got a used ACV but i wont get it till tuesday so hopefully that is what is causing my idle and acv to act like that.

 

Having/had the same problem, check your ISC solenoid, it might be stuck open.

 

Where is that located? I've never heard if it? Are you referring to the idle air control valve that is in the side of the upper manifold?

 

Yeah I think he meant IAC, which can cause jumpy idle sometimes.

 

I did a resistance test and i got 11 ohms, which is between specs

 

I ment ISC - Idle Speed Control. Check the FSM section F page F-81 and onwards.

I got roughly 11 ohms as well. But sometimes they stick open/don't work as they should. I checked it with my Datalogit and the duty was all over the place, then I disconnected the ISC and suddenly the car idled like a dream. I haven't pulled mine of yet for inspection but it's probably faulty.

So try and pull the ISC connector and see if it gets better.

 

Ok will do, thanks

 

I installed another Air Control Valve, New NGK wires, New spark plugs...still my ACV lets out a gasp of air when decel. It didn't use to do that so i don't know if that is normal. My idle will be fine and 5 sec later it will bounce up and down. If my headlights are on it wont idle like that

 

Stock ECU or PFC?

-Geoff

 

Stock

 

Iam at a stop like at my driveway, and if I give it gas to like 2,500 RPM and it would just go down and up, but if i turn on the headlights it will idle fine.

 

check and adjust the TPS, as well make sure the idle speed screw isn't set too tight, holding the idle up too high.

 

I had already adjusted my tps because it use to rev high and would rev stick, but i will check it again.
My idle screw (under the elbow) is closed all the way

 

there's another idle screw on front of the throttle body.

many people go for the air bleed screw under the elbow because then you won't disrupt the TPS adjustment, but if the screw in front is set too tight then the air bleed screw won't be able to bring the idle down low enough.

 

Ok, I think that screw is loose. I still stung about the fact that when im at a stop and i give it gas to like 2,500 it will jump down, but if the lights are on it will stay there steady.

 

Any other ideas? I want to start driving this car.

 

Problem fixed. I noticed two wires were ripped under my passenger harness, so i fixed that and cleaned all my grounds. So far so good