I own a 1992 Mazda 929 with a 3.0 V-6 at over 200,000 miles. I used advice from these forums and did a home diagnostic test using a paper-clip as a jumper. The codes I got were as follows... 1, long pause, 3, long pause, 8, long pause. Then they repeat. I changed the mass air flow sensor already. It starts but cuts right off if the air sensor is connected. When I disconnect the air sensor it stays at idle but the idle acts strange, it runs low (around 500rpm) and jumps up to about 1000 once in awhile by itself. Also, the car won't rev right either way.

 

Mmmmm, There is not a code #1 listed. However, code 10 is a single flash but the duration of the light being on should be twice as long as the flash for the #3 or #8 and they should be output in order of lowest # to highest starting at key on with check connector shorted. It certainly sounds like you have a faulty air flow sensor if it runs much worse when the sensor is connected. It will of course run very unstabe with it disconnected as PCM has no idea how much air if flowing into the engine and runs off of fail safe settings that are only there to let you limp in to a garage. By 'changed the air flow sensor' does that mean a New sensor or only new to this car??

#3 is for a fault in the distributor 'G' signal. The computer receives three different 'engine position' signal from the distributor, ( G, Ne1, and Ne2 ). G signal is the most important of the three. Fail safe is that the injectors are all fired simultaneously which does not make for a good running engine. No internal repair parts are available for distributor from Mazda so entire unit replacement is really the only cure.

#8 and #10? if that is the code are both pertaining to the air flow meter. #8 is air flow itself, #10 is intake air thermosensor. Both of these are easily set if you have the connector unplugged with engine running or trying to start. Both sensors are located with the same unit.

You might want to initially try to clear all codes by disconnecting the negative battery cable and stepping on the brake pedal for at least 30 seconds. Reconnect the battery and start engine with everything hooked up and either rev engine or drive for a short while until light comes back on. Then recheck codes and see what has returned from a fault and what was created by unplugging things.

 

I got an air sensor from the junkyard, two actually, and neither one worked. I'm getting a brand new one on Thursday. We'll see what happens.

 

Three different sensors with same problems does not sound good. Since sensor will not be here till Thursday try checking a few things before that. Here are a few checks for voltages at the sensor connector. The Solid Black wire and the Black w/ White stripe wire should both have good continuity to ground. Brown w/ White stripe wire should have 5.0 volts with connector disconnected or plugged into the sensor as long as key is on. This is reference voltage from the PCM. Green w/ Orange wire is signal for intake air temp and should be at around 2.5 volts at 68'F with connector plugged in and key on. White wire is Air flow signal and should be approx 4.0 volts with key on (not running) and connector plugged in.

 

HELP babyhuey, HELP!!!
OK, got a new sensor. Cleared the codes. Not much changed, just no codes now. If the air sensor is plugged in, the car starts but shuts off within a few seconds. If the air sensor is not plugged in, the car will start and idle as long as I want but it won't rev correctly. Now what? I'm stuck, I checked for codes and nothing came up. Thank you for your help so far. Please let me know if you can think of something else.

 

make sure you dont have any cracks in the air hose. i just changed my hole fuel injection almost on my 94 929

 

My air hose DOES have cracks in it, but would that really cause the problem. I have taken the air hose all the way off on other cars and used dryer hose for intake. They still ran fine. But maybe that's not the same with my Mazda. Any clue where to find a new one?

 

THANK YOU FOR YOUR HELP. I GOT A NEW AIR HOSE AND IT IS RUNNING FINE. THANK YOU SO MUCH.