Engine run with MAF disconnected?
 

Mine won't start with the MAF disconnected & dies if I unplug it. To me, that sounds normal & the way it should be, but I've read in threads where it sounded as if an engine should run with the MAF unplugged, just not real well or in Limp Mode.

Yes or No? :confused:

Re: Engine run with MAF disconnected?
 

I can say first hand I ran my car with the MAF unplugged for nearly a whole month. Whether I should've or not is a different story. There reason I did This was because I was replacing relays and sensors and was easier to troubleshoot this way. The car ran pretty well also. But my point is, it really didn't give me any trouble by having the MAF unplugged other than throwing a SES light.

Re: Engine run with MAF disconnected?
 

Hmm...Because mine dies when I unplug my MAF, when looking for any possible cause for a CEL code that varies between 33 MAF High Air Flow & 36 MAF Burn-Off.

Re: Engine run with MAF disconnected?
 

Replaced the MAF, all is good now. Bad MAF, yet no CEL code.

Re: Engine run with MAF disconnected?
 

Double post.

Re: Engine run with MAF disconnected?
 

Wow that was quick! Where'd you find a MAF and how much did you pay for it? I had terrible luck when I needed one. I ended up buying three used ones before I finally got a good one. On top of that I had to replace the wiring pigtails to each relay and the relays themselves. I'm thinking one of the relays went bad already cuz my car just started throwing code 36 again everytime I turn it on. You can never win with these damn MAF setups. lol

Re: Engine run with MAF disconnected?
 

Ignore the 36 to start with. Mine would switch between 33, 36 & no code. Couldn't make up its mind. ;)

I got one from Autozone & actually turns out it is a (slightly) higher CFM flowing circuit board design vs the stock Bosch cooling fin & wire element one.
http://www.autozone.com/autozone/par...mString=search

Re: Engine run with MAF disconnected?
 

I'm assuming the 36 is telling me the crappy relay I bought is already bad. If it's something more than that I'll be so mad! And nice deal on the MAF sensor! Hopefully that solves all of your problems.

Re: Engine run with MAF disconnected?
 

I had 36 coming & going at random. Sometimes it would come on while driving, sometimes not. Sometimes on restart it would stay on or off, sometimes not. Got so annoying & no difference in my mpg or the way it ran, I started ignoring the CEL. Then it plain stopped for years. Maybe the bad burn-off caused the MAF to fail? I dunno, but no 36 now that the MAF has been replaced. No telling for a month or so, then I'll "know" if 36 plans to come back.

Re: Engine run with MAF disconnected?
 

It's the most picky code of them all. lol. Guess it just decides when it wants to go on. Yea, mines the same way, sometimes on and sometimes off. Mine sometimes runs rich when the light is on.

Re: Engine run with MAF disconnected?
 

My MPG average has dropped about 3mpg on tank average, so mine running rich I wouldn't doubt.

Re: Engine run with MAF disconnected?
 

Well, you see, the way the MAF works is this:

The MAF tries to keep the heated film or wire (wire in your case) at a constant temp of 70*C. As air passes over the film or wire, the wire is cooled proportionally to the density of air passing over it. This is how the MAF obtains the "mass" of the air.

Now, the reason for the hot wire MAF's burn-off circuit is due to the small particles of crud that make it through the air filter. This crud coats the hot wire or film as air passes through the sensor. The burn-off function is used to burn off the crud that's built up on the wire to clean it off and restore proper function, similar to a self-cleaning oven.

If the burn-off circuit fails, the crud continues to build. As the crud builds up, more power is required to heat the wire to optimal temperatures, and the output voltage rises. As the voltage rises, the ECM is signaled that more air is passing through the sensor than is actually passing through the sensor, so more fuel is sent to the cylinders, enriching the fuel mixture. This will cause a code 45 (rich mixture) if it goes on for long enough, and may potentially set a code 33 for the MAF over-reporting the airflow through it (although this hasn't happened in my case).

So, yes, the failure in the burn-off circuit probably killed your MAF. You may have been able to use a MAF sensor cleaner to restore functionality, but it's too late now.

Re: Engine run with MAF disconnected?
 

One of the BEST explanations of a MAF that I've ever heard! Actually the best. lol. I never knew the technical stuff on how they actually worked, and that would make sense about how the car ends up getting innacurate readings from one. I actually swapped out one of my relays earlier today and got code 36 to go off. We'll see how long that lasts.

Re: Engine run with MAF disconnected?
 

Having a GM service manual teaches a lot of things, lol...

You may want to pick up a can of the MAF cleaner and use it as the crud on the wire may have built up to a point that the burn off function may not work. Keep in mind you MUST let the sensor dry after cleaning before you reinstall it.