Question-------------------------
Followup To
Question -
My daughter called me during the winter here (central Texas) to tell me her car would not start. When I went to check on it I noticed that I could not hear the fuel pump pressure up when I tured the key. I jumped to the conclusion that the fuel pump was bad and replaced it which didn't solve the problem. I then checked fuel presuure, spark, temp sensors etc. and everything seemed right. The car has sat in the garage since then, over the weekend I decided to make another stab at it. I had taken the airflow meter off but the results I got didn't make much sence so I decided to try to start the car while manually moving the door on the air flow meter and the car started. I put everything back together and it started again. I had worked on the car over several weekends during the winter and it never got close to starting but last night it started first try. The only difference between the last time I worked on it and last night was the air temperature, 50's to 60's during the winter and 80's to 90's now. Now the only thing I can say about it is that it is running really rich, lots of black sooty smoke which I think it was doing before. After I got it running last night I checked the o2 sensor and also got a bad/confusing result. Any ideas?
Answer -
Bill,
I would check the Air Flow Meter (AFM) as you already have, and replace the 02 sensor. If you pop the black cover off of the AFM you will see a little arm that touches a strip on a circuit board. As the door opens it moves this arm along the strip and tells the computer how much air is coming into the engine. These stips regularly wear out, causing a need for a new AFM. They are pricey, but low mileage units can be found far cheaper than dealership prices.
BMW O2 sensors are not cheap either, I guess it's just because it's for a BMW. I think they can be had for $100 or so. There is a little known fact about the 02 sensors on these cars. Ford used the same sensor in some of their vehicles, although the wire connector is different. The Ford O2 sensor is about $30, so it was worth a try for me. If you are comforable soldering wires, this could save alot of money. Cut the connector off of your o2 sensor, and solder it onto the new Ford O2 sensor. Both are made by Bosch, and are the EXACT same sensor. I'm currently running one in my car.
If you choose to go this route, bring your sensor with you, and ask for a mid-90's ford truck o2 sensor. These are for a V8 Truck. I think some Mustang sensors will work too. make sure that they have the same ammount of wires (should be 4), and are generally the same size.
Hope this helps,
Josh
Josh,
Is the cover to the AFM you are talking about the cover on the top as you look down on the AFM as it is installed in the car? The one that I think you are talking about is about 3" x 3 1/2". If so it seems to be glued down pretty tight, just wanted to make sure before I forced it.
Thanks Bill
AnswerBill,
Yes, it should be a black cover, about the size of a deck of cards. It is glued on, to keep moisture out. You can pry it up, but be careful not to crack the cover. I will tell you this; if there is a groove worn in the track, there isn't really any way to fix it. You are pretty much stuck with buying a new/used one.
You can test to see if the AFM is the problem though. Take a multimeter, ground one end, and place the other on the arm that moves on the track. Slowly advance the arm forward, and watch the voltage output of the meter... it should go up as the arm goes further down the track.
Hope this helps,
Josh
