I've got a 93 Mazda 626 that i plan on racing, i noticed today while moving it that when i just am light on the throttle it works fine, but as soon as i try to accelerate hard or rev it up fast it just spits and sputters and barely does anything.
Anybody be able to tell me what my problem is?

 

a 20 year old car with 500,000 miles on it that you just bought without knowing any service history and you want me to guess?
Bad O2 sensors, clogged main catalytic converter. Needs a tune up, clean the throttle body (or get new one), clean EGR valve, MAF, change PCV valve. Check fuel pressure.

 

Good to see I get an attitude with it...Just for the record, its got 190,000km and it was a good car, bought it off a friend of mine, got rid of it because it started to get too rustyp
It's a 2.5l V6 if its any help. MAF will be my first try, that seems to be what most people are telling me

 

Is it giving any check engine light?

 

Without more info you get what you get. You want a relevant diagnosis with no info supplied? Really?
READ and DO: https://www.mazdaforum.com/forum/new...-avatar-30905/
If you had as much info as i do in my signature, you'd get better results!
With that mileage all sensors are more than likely due to be changed!

SERVICE HISTORY! plugs, coils when last changed? Coolant changed? etc

 

For instance, if you tell us your car is misfiring here's a list of things you need to go through:
Missfires Can Be Caused By a Million and One Things,

Vac Leaks
Wiring Issues
Spark Plugs(Even Fresh Spark Plugs That Are Crappy Quality.... E3 And Such)
Ignition Coils
Alternators (Search EMI)
MAFS
Injectors
Injector O-Rings
Intake Gaskets
TB Gaskets
PCV Hoses
PCV’s
Malfunctioning EGR
Malfunctioning CAS
O2 Sensors
Aftermarket Intakes
Intake Hoses
Vac Lines
Timing Chains
Timing Chain Tensioner
Broken Cam Gears
Malfunctioning Cam Sensors
Incorrect Crank Gears(The I4 Has Like 40 Different Configurations For Whatever Reason)
Incorrect PCM Flash
Issues Within The PCM
PCM Wiring
Bad Diaphram Within The FPR
Issues Within The Fuel Pump
Dirty Fuel Filter
Dirty Fuel Lines
Pre-Cats/Poor Exhaust Flow

If the above gaskets/seals have not been changed, change them. Clean your MAF sensor, throttle body.
Change your PCV valve and probably that short hose as well.
Inspect the intake accordian tube for cracks. Inspect for vaccuum leaks.
Put in a good Fuel system cleaner: Red Line Synthetic Oil - Gasoline Fuel Additives - SI-1 Complete Fuel System Cleaner
Inspect wires. Re-set ECU after doing above.

WITH HI MILEAGE VEHICLES THERE IS NO EASY ANSWER!

 

Who says it's misfiring? It could be too much or too little fuel, I'm not stupid, I'm aware I didn't put down as much information as I should have, I types it as I was walking into work and added some more once I was on break.

I'm not new to mechanics, I'm a truck mechanic, but I'm not overly familiar with mazdas, e always raced Cavaliers before and I figure I would post it to see if anyone had had the same problem and might be able to pin point it rather than trial and error.

Sadly, most of the forums now are filled with people that like to pretend they're 10 feet tall and bullet proo, I'm aware I left out some information, so I added it when I got the chance.

I came here looking for some helpful advice, not to argue with someone.

If anybody has had a similar issue and fixed it, it would be greatly appreciated if you could tell me what you did to fix it.

 

You have obd1, does the check engine light on? If so, we can diagnoise what that is based on info from you, and obd1 codes.

 

The check engine light was not on but I had only had the car running a couple minutes since it started, ill leave it running longer and play around with it a bit tomorrow to see if it comes on.
I'm going to check the catalytic converter as well, the exhaust is broken after it and its dragging on the ground, I might check if one of the times I reversed the car if it got stuffed full of rocks and dirt.

 

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