recently replaced entire cooling system including head gasket...ran good for a couple of days now starts up everytime but only runs for a few seconds (6 or 7) then dies. Replaced fuel pump and filter, vacuum hoses, cleaned tank, fuel pressure reads 40 lbs. then needle starts to flutter downwards to zero til it dies.. have 12.6 volts to pump itself and live wire to pump stays lit using a test light. code 3 comes up but it has been that way for several years and ran pretty well. Recently code 5 came up for a knock sensor but is no longer there...... was told that model doesnt have a knock sensor anyway. anybody with an idea? Injector resistance tests are within spec. good spark, tried different pressure regulator with same results

 

I dug around a little bit and found that each manufacturer had his own list of OBDI trouble codes.
For Mazda I found this:

Mazda Code Retrieval

Accessing Trouble Codes
96 & later are OBD2 systems

91Mazda B2000 pickupClearing Trouble Codes


Carbureted Models
Fuel Injected Models With OBD
Fuel Injected Models With OBD II
Diagnostic Codes

Mazda

Carbureted Vehicles1No1 Ign Pulse9Water Thermo Sensor13Vacuum Sensor14Atmospheric Pressure Sensor15Oxygen Sensor16EGR Position Sensor17Feedback System18A/F Solenoid Valve22Slow Fuel Cut Solenoid23Coasting Richer Solenoid or Circuit26Purge Solenoid Valve or Circuit28Duty Solenoid Vacuum Valve or Circuit29Duty Solenoid Vent Valve or Circuit30ACV Solenoid Valve or Circuit34Idle-Up Solenoid Valve (for A/C) or Circuit35Idle-Up Solenoid Valve (for A/T) or Circuit45Vacuum Solenoid Valve or CircuitFuel Injected (Before 95)
Except RX-7 (RX-7 See Below)1Ignition Pulse.2Distributor - No 2 Signal.2No 2 Signal (626 and MX-6).2Crank Angle Sensor - No 2 Signal (1992-1995 929, MX-3 1.8L).3Distributor - G or G1 Signal.3Crank Angle Sensor - G Signal (MX-3 1.8L).4Distributor - No #1 Signal or G2 Signal.4Crank Angle Sensor - No 1 Signal (MX-3 1.8L).5Knock Sensor.6Vehicle Speed Sensor.6Air Flow Meter (MX-3 1.8L).7Knock Sensor - right hand side.8Air Flow Meter.9Water Thermo Sensor.10Intake Air Thermo Sensor - Air Flow Meter.11Intake Air Thermo Sensor - Dynamic Chamber.12Throttle Sensor.14Atmospheric Pressure Sensor.15Oxygen Sensor or Heated Oxygen Sensor - left hand side.16EGR Position/Function Sensor.17Feedback System or Closed Loop System - left hand side.23Oxygen Sensor or Heated Oxygen Sensor - right hand side.24Feedback System or Closed Loop System - right hand side.25Solenoid Valve - Pressure Regulator.26Solenoid Valve.27Solenoid Valve.28Solenoid Valve - EGR Vacuum side.29Solenoid Valve - EGR Vent side.30Cold Start Injector Relay.34IAC Valve.36Heated Oxygen Sensor - right hand side.37Heated Oxygen Sensor - left hand side.40Solenoid Valve - Triple Induction Control System & 02S Replay.40Solenoid Valve - Variable Resonance Induction System Solenoid Valve - VRIS 1.42Wastegate Solenoid Valve.46Solenoid Valve - VRIS 2.65A/C Signal - PCMT.67Coolant Fan Relay No. 1.69ECT Sensor.




So your MX3 is fuel injected and the code 3 refers to the distributor.

I hope this helps.

 

thank you those are better than whats in the book...but that cel has been on for several years....I did just unplug the maf meter and it stays idling but when you give it gas it dies sometimes..sometimes not...hopefully im in the right direction

 

That's shooting in the dark isn't it? With out the MAF sensor the computer won't know how much air goes in and it won't be able to calculate the proper amount of fuel. With the light on it is running on closed mode and uses approximate values that are programmed in.
The codes give you an idea where to look for causes, no matter how long the light was on. But the longer the light was on the more likey the catalytic converter is plugged or molten.
You already did a lot of work so it would make sense to do a little more. clean the throttle body and EGR system, clean the MAF sensor and use it!
Check the catalytic converter. there are several methods, Youtube for them. EricTheCarGuy and Briansmobile are good channels.

If the code tells you there is something wrong with the distributor I would check the distributor.

It's yor car, your time and your money.

 

thank you for your input...... have cleaned the throttle body, no cracks in intake boot, no egr valve. cleaned maf, disconnected exhaust at exhaust manifold to bypass converter ...same problem....have tried 3 fuel pumps and 2 pressure regulators...must have good pressure if it stays at idle with maf unplugged. but when you plug it in it only idles for a few seconds...any other suggestions?

 

thanks for the ideas....turned out to be the maf...........still wants to die when you come to a stop if accessories are on or you hit the brake pedal...but at least its running again......

 

If you've not done any inlet modifications, replace it. If it runs better unplugged it is using "old data", and not current as current data from the maf is not valid withing what the pcm is looking at signal wise.