Since i got the car about 3 weeks ago, its a 92 bird with a 305 tbi, everytime she starts up ok and drives good but as soon as it reaches operating temp, it will do some missfires , i dont rly know whats wrong but something like that, the idle needle will go below 500 and bounce up and down by a few ticks between 450 and 500 rpms and it just randomly while holding light on the brake when one of the missfires occours the car wants to go like if it was being accelerated.

It was giving me a code for EGR k installed new one, installed new plug wires and gonna install new plugs, atm car is running with 4 new plugs and the rest are the ones that came with it, i looked at the old plugs and they looked kinda ok but w.e new plugs go in anyways. My brother keeps telling me that its due to a bad Idle Speed sencor cuz of how the car idles , while i tell him that it could be bad timimg. Oh and a new cap and rotor was also put in new.

But its weird cuz it only does this while in Gear , as soon as i turn the AC on my idle rpm go up a little and all the missfires dissapear, also they dont happend while car is being accelerated.


Another thing is i think what its doing its Detonations, cuz thats what those missfires feel like,it literally shakes the whole car up and wants it to go forward even while holding the brake , like if the explotions happend randomly rather than when they are suppost to. Now i started using some premium gas for now on since while using low octane one i could hear piston knocks.

 

Check for a contaminated oxygen sensor.

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Happy Racing!

 

Idle Chatter and Contaminated oxygen sensor ?

Is this an answer , sry im a little confused by your post with all the colors etc.