What could cause this

[t3intercooled]

I do want to preface this by saying the injectors are used however its been working perfect for the month or so that I had the car out. Now this just started last night and continuing through today. any time my foot is off the throttle, weather it be sitting at a stop light or if im driving and take my foot off the gas and just coast this happens. the cars idle fluctuates where sounds fine thwn falls down then sounds fone then falls down and continues like that on and on and on, all while the scanmaster 02 readings when the idle is fine are read 800s, then when it stumbles the 02s read .0 something then when the idle comes back up they go back up round 800s and it continues with that pattern. any ideas?

 

[groumoutis]

Is it jerking as you coast?

 

[DaySleeper]

Sounds like a vacuum leak. Maybe coming from PCV valve or something.

 

[t3intercooled]

no it doesnt jerk when I coast. All that happens is the rpms go down then up and so on and the 02s go from fine to lean and fine to lean and so on

 

[groumoutis]

Check the fuel pressure and see it is is holding steady. I would look into the vaccum system like Day sleeper said. What are your scanmaster readings at idle with the car warmed up. Mainly the blm. If you have a leak your blm reading will be high. Depending how bad the leak is.

 

[GNRick]

Just a guess...bad tps sensor or bad MAF sensor?

 

[t3intercooled]

Okay that fixed itself, but now another issue. scanmaster screen bl read 125 at idle when warm. Now something else is happening. my computer is not allowing me to post videos. Does anyone no these cars and no scanmaster readings very well so i.can send a video of my scanmaster to their email?

 

[BadAssGN]

I'll take a look. Send to camaro_ragtop at hotmail

I'd be looking at maf readings. Sounds like its acting up at low flow

Hopefully you show all the parameters in your vid