Hey guys. I'm trying the UDP again but this time I'm going to install an overdrive alt pulley. It's coming in tomorrow so I put the UDP on today now my car has an intermittent miss. The CEL comes on flashing and it sounds and feels like it's running on 4 cly. then suddenly it runs good again. We scanned after the first time and all it showed was and intmittend miss at start up just like last time except now it says cly. 3 & 4, last time it was always 1-5. What the heck is going on? It ran great with the stock pulley and last time with the UDP it did too except the CEL came on and stayed on. It's on again now too but when it starts to miss it flashes. It doesn't matter how fast I'm going when it act's up either so there is no rhythm to it. I need help fast. Anyone have an idea what is causing this?
i saw the previous post.. did you put the stock pullies back on? and still have the misfire? this is probably coincidence it started with the pulley swap.. if you reinstalled the stock pulleys and still get a cel on... the first thing i would do is check the coil.. having two misses like 1-5.. 3-4.. 2-6 tells me coil.. whichever cyl# is missing if it has a miss on the corrosponding cylinder chances are big its a coil.. in simple terms...a flashing check engine light means damage to the converters is going to happen.. service immediately..not later...
No it ran perfect with the old pulley and no codes either. This time I even swapped reluctor rings, now it throws a code and has a bad miss and it started doing it about 3 minutes after I was done. The latest update is I talked to Lee at ASP. His feeling is the UDP is not balanced. One of the possiblities for a random misfire is an out of balance engine so it' makes sinse. If anyone installe one and has a misfire, send it back.
OK i never heard you state you were replacing the harmonic balancer, i thought it was just the underdrive pulleys.. why did you replace the ring? that is the crank sensor ring basically telling the computer where top dead center is for the ecm. if the teeth are even millimeters difference theres a problem.. did you replace the balancer also or just the ring? can you put the orig ring back on ? i dont understand how it could be a internal balance issue if you did not replace the balancer... your problem definately is the reluctor ring..is there more than one keyway? give the part # STAMPED and find out if mabye they gave you one from a different year? the crank sensor is not seeing the correct amount of spaces in the ring when reaching t.d.c. causing the ecm to generate a misfire code because the injectors are not firing at the correct time.. whether its misfiring or not the ecm is saying it sees quite a few... does it run and drive o.k. because it shouldnt.. it may not be bucking but is it underpowered? put everything that was stock on the crank.... back on, use the udp's on the wp and alt only and see what happens.. no other scenerio would cause this to happen.. it is whatever you attached to the crankshaft..
if you did not replace the harmonic balancer... the udp's would not cause an engine to go out of balance unless it was cut in half and you installed it that way.. it would have to be seriously warped and that would be visable while the car is running...dont let them blow smoke up your ass....return that headache!! for the extra 5 hp (mabye) and numerous cel's it just dont seem worth it... reliability would be my concern..
On the 00-04's the balancer, ring and pulley are one unit, that's why I had to replace the balancer. I put the new pulley on a brake lathe just to spin it at a low speed and the ring was not centered at all on the new pulley. Then we tried swapping the rings and it got a little better but the way they are made the ring can move a little in all directions so it's impossible to center it perfectly. When we put my old ring back on my old pulley it was suddenly throwing the same code and yes it does feel like it lost some power. Looks like I have to get a new stock pulley now just to make it run right again. There was several guys suggested swapping rings and none of them said anything about how critical the alignment was. At least I know why the new one was screwing up now.
the basic way to set any ring is to set it on tdc#1compression stroke, there eitherhas to be a marked indentation in the ring or one of the tooth openings or window as its called should be slightly larger than the rest... once on tdc you set the ring widest tooth directly under the crank sensor... what you have is a miscommunucaton between the crank and cam sensor they are what you call out of sync.. caused by the ring you removed and replaced.. hope all works out such a downer when **** like that happens!!
The way the ring mounts is with 3 small bolts and the holes in the ring are big enough that the ring can move around in all directions, not much but it's enough to throw it out of whack. The miss is gone but it still throws a code. One guy told me they are computer aligned using lasers. If that's true I don't know but it's almost impossible to line it up perfectly the way they are made. I don't know why they don't have some alignment pins or some thing. I guess that makes it too easy.
