Where to start? I bought an 88 camaro a couple of years ago, as a project car. Now it is my daily driver. In the course of repairs i have been throught about every sensor, wire and connector. I am no slacker when it come to auto repair. However, i have found a problem which i can not figure out so i come to you for assistance.

This is a 2.8l mpfi vin code S. The mass air flow sensor is stuck at 2.5V. This is a new sensor, in fact it is the third, and they have all done the same. I have gone throught the wireing for shorts to hot, shorts to ground, replaced the ecm, rewired the pigtail, bypassed the harness.
Not to mention all the tests that i could find in any book i have ever seen.

Nothing I have done makes any changes to the system.

Well, This is the question.

NOW WHAT?

 

The MAF IIRC is not a DC sensor like the TPS or something; it's an oscillator whose frequency varies with the airflow. Therefore the voltage you see with a DC meter will always be about the same.

If you look at it with a scope you should be able to see the output waveform.

What are you trying to repair? What does the car actually do wrong?

 

Killier,

Welcoem Aboard!

RB covered it. Just to expound upon that information a bit, what RB offered is true for your particular engine. The MAF sensor on 1985 V-8 TPIs and all V-6 MPFI engines is NOT an analog output device. It will output a variable frequency or duty cycle square wave at an average amplitude of 5V P-P. The output frequency is relative to the intake air flow being measured. These are commonly referred to as digital, or frequency-modulation (FM) type MAF sensors.

Only 1986-89 V-8 TPI engines used an analog output MAF sensor, with a variable voltage signal. Your MAF is probably operating as it should. If you are hearing conflicting or contradictory information regarding the diagnosis of your sensor, that may explain the reason. Your meter is likely averaging that output to arrive at the 2.5VDC indication, which is what most meters would do. Only an oscilloscope or duty cycle meter (such as a dwell meter) will display relevant information you might need.

 

Finally, Thanks so much, I know the book had to be wrong.

The real problem is at an idle all power on it gets alittle rough. Just started looking around and checking things. I found this and have been going insane eversense. Wasn't sure if this was a cause or effect.

i love this site.