Problem with UDP

[raz54]

I finally got the ASP under drive pulley (25%) and put it on and within 10 minutes the check engine light came on. I scanned it and it said there was a random misfire within the first 1000 rpms of running. I sure didn't feel any though. I cleared the code and later that day it came on again with the same problem, random misfire and one possibility is low voltage on start up. The engine spins over fine though. I removed the pulley and inspected it and it looks perfect so I put the old back on and no more codes. I also tested the battery and alternator and both are fine. Has anyone else had this problem with an UDP? Would an overdrive alt pulley cure it? I don't want to have to return the udp but I sure can't have the light on all the time.

 

[2002BLGT]

I finally got the ASP under drive pulley (25%) and put it on and within 10 minutes the check engine light came on. I scanned it and it said there was a random misfire within the first 1000 rpms of running. I sure didn't feel any though. I cleared the code and later that day it came on again with the same problem, random misfire and one possibility is low voltage on start up. The engine spins over fine though. I removed the pulley and inspected it and it looks perfect so I put the old back on and no more codes. I also tested the battery and alternator and both are fine. Has anyone else had this problem with an UDP? Would an overdrive alt pulley cure it? I don't want to have to return the udp but I sure can't have the light on all the time.

probably something to do with the reluctor ring on the balancer on that setup , check the clearance between the crank sensor and the ring on the balancer

 

[raz54]

That was my first thought too but they are a perfect match and according to ASP that and the balencer are Ford parts. I'm going to see if they sell an overdrive alt pulley for mine and if that is the problem it should cure it.

I've been driving 2 days now with the old pulley and still no service engine light. The only thing it can be is low voltage from the smaller pulley causing a misfire.

 

[2002BLGT]

That was my first thought too but they are a perfect match and according to ASP that and the balencer are Ford parts. I'm going to see if they sell an overdrive alt pulley for mine and if that is the problem it should cure it.

I've been driving 2 days now with the old pulley and still no service engine light. The only thing it can be is low voltage from the smaller pulley causing a misfire.

True didnt think about that , could be a possibility I know when the alternator diodes go back on the 01-04 GTs they have been known to throw a cam sensor code because its wired up in the same harness , guys end up putting cam sensors on and its the alternator the whole time .

 

[raz54]

I'm going to try an over drive pulley for the alt (if I can find one) so hopefully that will cure this. I really liked how the car was more responsive with it. When I do I'll post the results in case anyone else runs into this.