No MAF in 91--Why??

[vette-dude]

My 91 w/L98 does not have a MAF in the intake ribbed air hose like my 94 and other years have. What years do not have the MAF? Why is this?? What device takes its place if any? Could someone take the time to explain. Thanks

Randy:confused

 

[taegdh]

Long about that time they switched form using a Mass Air Flow sensor, to a different algorythm, which had to do with speed. (What it was called escapes me at the present time, Speed Density something rings a bell. ) But due to change in designs and emissions in the mid ninties, they went back to a MAF.

I also believe the mandated OBDII, legislated in the mid 90's, may have been a contributor to this.

 

[vette-dude]

Thanks for the info. I was just wondering if there was anything I needed to check during a major tuneup with this non-MAF system. Not having any codes or anything and every thing seems to be okay but if there was a maintenance item that needs attention I would like to get at it now ( before I get any older and can't get on my knees to work on the engine)!! So far all ignition components have been replaced along with the 02 sensor, PCV valve, and fuel and Air filters. Am cleaning the TB this weekend. Going to Super Chevy this weekend also and hope to get some new semi-metallic or carbon fiber brake pads at a reasonable cost. And no I am not racing this year but have a warmed up SB on the stand in the garage and you never know what a guy might drag home from the car corral at these events. Thanks again and if anyone wants to chime in with advice it would be very welcomed.


Randy

 

[vader86]

You run on a Speed Density system, that uses a MAP sensor to detect incoming air pressure. The MAF and MAP basically do the same thing, but from a different perspective.

85-89 and 94-96 have MAF, the rest use SD.