Mazda Miata

1999 Mazda Miata Engine   

Driving in traffic, my cars started idling very very rough and the tachometer ws jumping all over the place. I gave it some gas because I thought it was going to stall. It just perfomred rougher, then there was a loud pop or bang from the engone compartment and it stalled. I had to wait ten minutes before I could start it again. I limped it for about nine miles to a service station and it cleared up a half mile before I got there. The OBD says I have a p0102 and p0304 code, but the mechanic couldn't get it to duplicate after clearing the codes.

The 304 code is for a misfire in cylinder number 4. The 102 is for low maf output (the airflow sensor for the engine.)

One thing that is possible is that you had a bad dose of gasoline, hard saying.

The wiring and ductwork around the MAF should be checked to make sure there is not a problem. The sensor itself could be dirty (clean its filament with spray electrical cleaner) or failing (have to wait and see.)

The P0304 misfire code is most often caused by a bad spark plug wire or spark plug. Of course a coil problem cannot be ruled out, along with fuel supply (injector or pressure) or quality (possible bad gas as mentioned.)

I don't think it was a bad bit of gas. I had it happen twice, about a month apart. I am changing the spark plugs, wires, and fuel filter. Where do I find the MAF sensor and what do I do to clean it?

Spray it with spray electrical cleaner.

Use the following link, copy and paste into your address bar-
http://www.partsamerica.com/VehicleSelection.aspx?destinationpage=default.aspx


Enter Year, Make, Model, etc to access parts for your vehicle. Select the mass airflow sensor to view a picture of the part.

Is is located just before the throttle body, in the large air duct.

1992 Mazda Miata All Part Groups Stalling When starting Always

starts and runs for 3 seconds then dies. fuel pump is running o.k.

there are a number of things that can cause this.
The first thing you should do is run a dianostic from the pcm and see if there are some stored codes.
Do a fuel pressure test to make sure that you are getting fuel to the fuel injection port.
It is possible that the fuel filter itself is clogged or clogging as it gets pressure from the pump the injectors may be dirty also.
Another thing to look for would be a vacume leak in the intake manifold causing the fuel air mixture to be unbalanced
I hope this helps

fuel pressure was checked and its o.k. i dont have the equiptment to check the pcm or I would not be asking you.

Check the fuel injectors, if one is shorted it will cause the injector driver to go full open signal. Disconnect the fuel injectors to test resistance across the terminals to located shorted injector.
the ohm readings should be consistent

"I agree the firs step is to check for diagnostic codes.

See if the instructions at the following link match the diagnostic connector used on your car. I recommend using a fused jumper wire (5 amps is plenty) instead of a paper clip when using the self diagnostics.

http://www.miata.net/garage/faultcodes.html

1990 Mazda Miata All Part Groups  When driving No pattern

Hi, I have a 1990 Mazda Miata and the oil pressure gauge needle seems to fluctuate. When I'm on the highway the needle will be above 30 and when I come to a stop, it needle goes down to below 30. Is that normal? I never noticed that happening before and recently I had to have a fuel pressure regulator put on the car. Thanks.

It is normal for the oil pressure to change at different engine speeds.