Hey guys,

I mentioned I'm having a VERY rough idle issue and occasionally stalling out after installing my Hotcam kit. I was fiddling with it today, and I found out that if I unplug the MAF, the idle smooths out and the car doesn't die...

On the downside, it instantly gets 0.3 up to 5.0 degrees of knock retard, and it stumbles below 1500rpm... Of course, I know it is supposed to run with the MAF.

Think I have a bad MAF? BTW, what is a good idle reading on the MAP sensor? It said around 30 on my Scanmaster.

Thanks,

Michael

 

You don't have a bad MAF. Have you upped your idle at all?

Ben

 

I think when the MAF is in the system, the PCM reads from many sensors including the O2's and calculates fuel settings and engine speed accordingly at idle. The part I'm not sure about is when the MAF is disconnected I think the PCM refers to internal tables and ignores sensor input.

If that is the case it could be that there was some contamination to the O2's after your install that caused them to stop functioning properly. If they are old you may want to replace them.

 

So it could be O2's instead of MAF?

I have the following error codes on my Scanmaster:

27, 33, 44, 48

Where do I start?!....

BTW, I think it is POSSIBLE I blew out an O2, because I plugged up the AIR injection on my headers using a penny and some copper RTV. When I first cranked it, I got a bunch of smoke under the hood when the copper RTV burned off...

Thanks,

Michael

 

If MAF is unplugged the computer still reads everything else guys including the o2's, it just switches to speed density mode thats all. so if you unpluged the maf & its ok then chances are its either a bad maf or a vacume leak.