Contour Enthusiasts Group Archives Forums General Troubleshooting sure enough, it was the MAF (was: MAF voltages)

Okay, I voltmetered my MAF, and it reads like 0.9 volts at idle and 1.7 volts at 3000 rpm in neutral. According to this , the idle reading is a bit on the high side... but I don't worry too much about that given that contamination would tend to lower the voltage, not raise it. Does anyone think these readings indicate anything wrong?

I'm inclined to just clean the wire again, maybe with two or more different chemicals for better luck, and see if the reading changes at all. If anything is wrong here, it's subtle. And yet the engine would hardly rev smoothly when I pulled the throttle open to get the upper reading...

IIRC the proper MAF voltage @ idle is .86 - .89V
Your .9V sounds just fine.

I finally tried the old trick of disconnecting the MAF and seeing if the engine ran better without it. Sure enough, it did.

I should have done this with the oxygen sensors before buying new ones... though those might have been worth replacing anyway. Even if still working adequately, I know they weren't good as new.

I unscrewed the top of the MAF and pulled out the core... and sure enough, the two wires were covered with fuzy black deposits on the upstream side. I just cleaned them a few months ago! And furthermore, at that time, they didn't have any such coat of dirt on them even before the cleaning. Either something got some sticky gunk in there, or the CTA cone filter is letting through too much dirt. Or both. The latter is almost certainly true, judging by the fine film of dust on the silicone gasket that attaches to the throttle body.

Anyway, it appears to be running fine now. My previous MAF cleaning didn't produce such good results, so maybe one of the other things I did also fixed something. Or maybe I cleaned it better this time. I used solvent, gently brushed the deposits off, then put penetrating oil on it. I hoped that might get under any remaining gunk. Then I used solvent again to get the oil out.

Anyway, thanks to those who steered me back to the MAF after I thought I had eliminated it from the list of suspects.

Now I'm free to install my e-RAM, if I find any free time.

What is your MAF voltage @ idle now that it is clean and working better?

About 1.0, and 1.8 at 3000 RPM in neutral -- 0.1 higher than before in both cases.

Now I want to voltmeter the throttle position sensor. See, I was installing the switch for the e-RAM, and just when I had it just about finished, after fabricating a specially shaped plate to mount it on and everything, their cheap switch broke. So now I'm thinking of maybe making an electronic switch that monitors the throttle position sensor, instead of replacing the mechanical switch with a similar one.