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View Full Version : 1990 pontiac Bonneville MAF test?


chazf
Oct 26, 2011, 05:58 PM
Anyone know how to test the MAF
On a 1990 Pontiac Bonneville with the 3.8L V6?

RickMN
Oct 28, 2011, 01:49 PM
Pretty hard for a DIYer. You need to attach a scope. FWIW, they have a pretty high failure rate.

odinn7
Oct 28, 2011, 03:00 PM
This is a little off the wall but there is a test you can do that will sometimes show if the MAF is bad. While the car is running at idle, take a screwdriver handle and tap all around on the MAF... DON'T hammer on it, just tap it. If the idle changes as you tap it, the MAF is bad. It's not a complete test but it does work sometimes. Worth trying.

RickMN
Oct 28, 2011, 05:42 PM
You can also disconnect the MAF and drive it. That will set the check engine light. But if it drives better with it disconnected, that's an indication that the MAF is bad.

Sorry, forgot about that little trick--should have mentioned it in earlier post

chazf
Oct 29, 2011, 07:53 PM
Thanks guys.. I changed four of them all with same result.. I disconnected it and drove the car, but it still won't rev out clean and dies when the sensor is plugged in.. It also backfires a bit, and I noticed a lot of grey fluid leaking from the coil pack, so I'm thinking that it has broken down.. Seen as how the info the MAF sends to the ECU controls fuel and spark, the CP may be the major cause of the problem.. That'll get changed as soon as the rain stops...