My 1993 Mazda MX-3 GS is running rough. (2 days ago) I start it and the rpm's bounce, then going in first gear is jerky. I look like someone who can't drive stick. (today) first and second gear is now jerky and it cut off on me four times on my way home. It cuts off after I stop moving and the rpm's gradually decrease to zero. Can anyone help me. Thanks in advance.

 

Wow, a 19 year old car. Where do you start! Is that thing carbureted or throttle body? Everything should have been changed by now.
I would start with checking vaccuum leaks.
Miles? Service history?

 

In the absence of more history on ther car here's a few more for your list to check out or replace:

Ccheck that battery voltage is above 12 at idle and connections are free of corrosion and wires and their insulation are in good shape .

Rev the engine and see if motor comes up off of mounts. this could cause shorts or breaks in the wiring harness.

Check for or tighten bad wire connections at the fuse box

Make sure electrical ground connections are good, clean/ free of oxidation
start it up at nite or where it is dark and see if there is any corona or spaking goiung on. You can spray water mist from a spray bottle in suspect areas and it will accentuate the sparking

Change the fuel filter(s), check out fuel pressure regulator, and fuel pump.

could also be electronic inputs to igniton system computer like TPS, idle air control, MAF, coolant temp sensor, etc. or relays like the main relay, and the fuel pump relay, if it has these.

If it has a distributor, replace or check the cap and rotor for carbon tracking and general condition, and of course the spark plugs.
Clean the throttle body

Start with easy and cheap things first like visual inspection of wires, and keep a list what you have done.

send us more history, like how many miles on it, has it been sitting long, recent components worked on, does it smoke from exhaust and what color, etc.

Good luck.

 

SO HERE IS WHAT IV'E GOT FROM YOUR REPLY. RIGHT NOW IM RUNNING SEA FOAM THROUGH IT TO MAKE SURE THE INJECTORS ARE CLEAN.

Check that battery voltage is above 12 at idle and connections are free of corrosion and wires and their insulation are in good shape. THIS IS GOOD

Rev the engine and see if motor comes up off of mounts. this could cause shorts or breaks in the wiring harness. WHAT DO YOU MEAN OFF THE MOUNTS?

Check for or tighten bad wire connections at the fuse boxTHIS IS GOOD

Make sure electrical ground connections are good, clean/ free of oxidation
start it up at nite or where it is dark and see if there is any corona or spaking goiung on. You can spray water mist from a spray bottle in suspect areas and it will accentuate the sparking HAVEN'T TRIED YET

Change the fuel filter(s), check out fuel pressure regulator, and fuel pump.ORDERED A FUEL FILTER, BUT I CAN'T FIND WHERE IT'S AT. AM I BLIND OR IS IT HIDDEN WELL?

could also be electronic inputs to igniton system computer like TPS, idle air control, MAF, coolant temp sensor, etc. or relays like the main relay, and the fuel pump relay, if it has these.WHAT IS TPS? IDLE AIR CONTROL IS GOOD, WHAT IS MAF?

If it has a distributor, replace or check the cap and rotor for carbon tracking and general condition, and of course the spark plugs.
Clean the throttle bodyHAVEN'T LOOKED AT DISTRIBUTOR, SPARK PLUGS ARE GOOD.

send us more history, like how many miles on it, has it been sitting long, recent components worked on, does it smoke from exhaust and what color, etc.IT HAS 108,000 MILES, IT SAT FOR ABOUT TWO WEEKS, SOME SMOKE, IT'S WHITE.

THANKS

 

MAF is your MASS AIRFLOW SENSOR. It is located in your air induct between your airfilter and upper intake manifold. It will have a small wiring harness going to it. With out the MAF sensor, the engine will be a no start, but can cause problems when going out.

 

OK I checked that too, it's good