Forest37

1996 A4, 2.8, 5sp, 2wd

Disassembled and cleaned MAF in normal manner (spray cleaner) - now the car won't even try to start. Fuel seems fine, no spark - will a MAF failure cause no spark? Is there any simple way (ohm measurement, jumper, etc.) to confirm a faulty MAF?

Thanks!

Lago Blue

Are the sensor wires intact?

Perhaps the electrical connector plug terminals require cleaning also? Sometimes just detaching & re-attaching the plug several times helps.

Some reading here re. trouble-shooting MAF sensors (from Jeff Hartman's excellent book):

http://books.google.ca/books?id=RYsg...sult&resnum=10

spider9

would appreciate any instructions on removing the maf sensor. I know it's under the filter box, but what's the best way to get it out?

Lago Blue

remove it. My '93 90CSq starts with the MAF unplugged. However, if I unplug it while running, then it dies, but it will start again without it. I think it's a sort of fail-safe feature.

If your issue is no spark to all six, your issue -may- be the POS unit/module.

Have a look at these two entire threads:

https://www.audiworld.com/forums/sho...php?p=22377563

https://www.audiworld.com/forums/sho...php?p=22436114

Another thing to check is the wiring from the POS to the coils under the Intake Manifold, it gets hot, the insulation fails, and you may have a short, but that is more likely to kill only one coil at a time.

Lago Blue

the brown/black thing.

CRAZY_RUSSIAN

HEY, where did u get that heat sink?

Lago Blue

nice though isn't it. Sadly' it's NLA. STFA and yee shall find.

Lago Blue

no photos, but it may help.

<ul><li><a href="https://www.audiworld.com/forums/showthread.php?p=22383051">moribundman's original article...</a></li></ul>

Bryans12v

It wouldnt be the MAF preventing the car from starting. It would start in open loop map. Check the ign amp plug to make sure thats plugged in, you had to disconnect it to get the MAF off, right? Its the flat sensor that bolts to the heatsink on the upper half of the airbox.