I have a 1998 Mazda MPV 2wd 3.0 liter V-6. The harmonic balance came off while driving. Just the first 2 pullies. The rest is still on with fan belt The check engine light came on and flashing. Just did get it home.. It starts fine but cant accelerate.. Didconnected battery to clear codes and now runs worse. Have to puch gas pedal all way to floor to get it to move. Can anyone help?

MC Covan

 

This picture shows the tone ring as part of the balancer. This is what the crank position senor is trying to read. Maybe the tone ring was damaged or the crank sensor has been damaged or moved from it's proper location.

 

Thanks for that info, but mine does not have that. It doesn't have a crank sensor. That's why I was wondering where to go to next. It acts like it not getting fuel. It will idle but you have to keep patting the accelerator to get it to rev up.

 

Your trouble with the engine started after you tightened that balancer which came loose.

Either the balancer is bad, or it is mounted incorrectly.

This is what a balancer does:
Every time the cylinders fire, torque is imparted to the crankshaft. The crankshaft deflects under this torque, which sets up vibrations when the torque is released. At certain engine speeds the torques imparted by the cylinders are in synch with the vibrations in the crankshaft, which results in a phenomenon called resonance. This resonance causes stress beyond what the crankshaft can withstand, resulting in crankshaft failure.
To prevent this vibration, a harmonic balancer is attached to the front part of the crankshaft. The damper is composed of two elements: a mass and an energy dissipating element. The mass resists the acceleration of the vibration and the energy dissipating (rubber/clutch/fluid) element absorbs the vibrations.


See if a new balancer will fix it. After all it came loose for a reason.

 

The balance has been on there a little over a year. Replaced it when water pump and timing belt went out. when we removed it, it fell apart so had to relace with a used one. The van has been running great since then. Just a couple a weeks ago coming home it came apart. the front half came off with the P/S and A/C belts. The rest is still bolted to the crank with the fan belt. So I guess what your saying is correct about it running bad after it came to pieces.. I have ordered a new one from Mazda. No more used for me. I really love this van. Everything works and a/c will freeze you out...lol Thank you so much for your input. This was just a new problem for me and first Mazda I ever owned.., Thanks again

 

Mccovan:

You are welcome!
...and when you get tired of the frost bite, dial up the temperature!