1995 Protege 1.5
120K
Recently had oil/filter changed, cap/rotor/wires replaced. Plugs are fairly new (less than a year)

I had all of this done because it was cutting out during acceleration. Mainly at lower (<40mph) speeds. After all of this work was done, it was still hesitating, but was much better. A little extra push on the accelerator would kind of "coax" the car through the rough spots.

I have been driving it on the highway once a week (30 miles total each week), and it has been ok. Still a little hesitation, but not terrible.

Yesterday, I drove it 15 miles on the highway, got off the highway, and shortly after, the car was shaking. Put-put-put. Popped the hood, and the engine is shaking. Shut car off. Realised that I cant afford major work, let alone a vehicle to replace this one.

I havent started it since, just out of fear of causing more damage. I only drove it about a mile to safety when this all happened. The previous hesitation seemed to go away.


This is my first post here. Joined to get some knowledge from other Mazda owners. ANY and ALL help is much appreciated.

 

Misfiring prior to your tune-up may have caused catalytic converter failure. You should have your exhaust pressure checked. Fuel supply could also be an issue.

 

A shot catalytic converter won't cause what you've described. fuel supply is more of an "upper end starvation issue", not an idling one. You should get an OBD2 code readout on this engine before anything else. You don't state this, but you imply that once you've got the engine up to cruising speed it's not so bad, so it sounds like a "low end regime" problem. If so, you'd be looking at the MAF sensor, THE INLET AIR DUCTING ESPECIALLY (it's really good at hiding cracks which open up and close as the engine shakes on its mounts, this plays merry hell with the idling), and the front O2 sensor.
Don't spend a dime on O2 sensors or a catalytic converter though until all the cheaper options have been thoroughly explored first, and even then ONLY if the diagnostic codes clearly and unambiguously identify these items as culprits.
Oh, I almost forgot. At only 30 mi./wk. you might have a low battery situation. With everything off, your battery should be up near 13 V. Put the headlights on, but don't start the engine. After 10 minutes you should still be seeing over 12 V. Start the engine and run it at a fast idle, you should see around 14 V. If you don't get numbers in this ballpark, get the battery charged and recheck. Everything goes to hell on these cars if the battery voltage drops below 12 V.

 

1995 isn't OBDII, so he can't have it scanned.

i see the basic tune-up work on the list, but i don't see a timing belt replacement in there. the timing belt probably jumped a tooth, which would cause the hell on the bottom end that you are speaking of and the smoothness on the top-end. the timing belt should be at least inspected every 60k miles, which means that it should be done right now on your car for the second time. personally, i replace mine rather than inspecting them at these intervals. by 120k, i would recommend a new tensioner as well.

 

wsoape281 makes a good point. If the timing belt looses a tooth, it can get progressively worse as it jumps further and further out of time. Being only one notch off is barely noticeable. OBDII is very nice, if your car is post 1997. I've never seen a MAF sensor cause such violent behavior in an engine. When they fail, the ECM should just fall back to open loop operation. Anything's possible, I guess. Good luck.