mustang fanatic

Hey Everyone,

I need some input and some help please! Over the weekend I tried installing MAC U/D Pullies on my 1994 Cobra. I ran into some problems so I ended up just installing the Crank Pulley and a new belt. As of right now I have all other pulleys stock. The test drive yesterday was fine, no problems occurred. But today on my 40 mile commute to work I started having some problems. When I was in some stop and go traffic the car would sputter and jerk as if it wanted to stall. I really had to get the rpms up high before shifting into 2nd or 3rd. Also when cruising around 50mph If I put it into 5th the car would do the same thing. In 5th gear going 70mph everything was fine. Also, when stopped at a light idling the voltage gauge would jump back and forth a few millimeters past the center line of the "normal" range. What is going on here? Any solutions? Thanks for any help/info!

FivePointOhh

underdrive are known for charging and temp issues. just keep the crank pully and sell the others. they're hardly worth the money for the nominal gain IMO.

mustang fanatic

But I am having problems with just the crank pulley. Should I just go back to stock?

FivePointOhh

mmmmmm....sounds like an underlying issue with your charging system. maybe poorly functioning alt/weak battery. check your connections for corrosion.

mustang fanatic

Even though the car ran fine before I changed the crank pulley? How can I check to see if the alternator is going bad?

FivePointOhh

take it down to have it tested at an autoparts store.

mustang fanatic

So I called MAC and the guy said that it isnt good to just have the crank pulley. He said the engine is being under driven and that the charging system isnt working properly because of it.

FivePointOhh

it'll get worse with the wp and alt pulley. you have some kind of underlying issue, you need to find it. i suspect you charging system is performing sub par at the moment.

mustang fanatic

Okay thanks! I will go to O'Reily on my way home. So what if my Battery and Alternator are just fine?

redemption

ya i just swaped my crank u/d pully for a stock one i am having major temp issues