June 25, 2002
Stock pulley here we come
Changing our whisper under drive pulley back to stock
We removed the HyperTech Power Programmer Three (656 days ago) and found that the power tuning was not the cause of our knock retard. It has been some time since the last installment in the hunt for knock retard, but nevertheless, we have continued our search.
In the articles leading up to this point, we have been skeptical of the whisper under drive pulley causing our knock retard. There was a bad batch of pulleys that were sent out back in 1999 and got into the hands of a few customers. This was one of the main reasons we suspected a bad pulley. A “bad” pulley means that a pulley is out of balance and causing vibrations, which results in knock retard.
We started the evening by replacing the Whisper under drive crank pulley and alternator pulley with the stock pulleys. This job was accomplished in under an hour and a half, with us breaking little to no sweat and taking our time. With two people straining their guts out trying to remove the crank pulley bolt and then reinstalling, it makes it more enjoyable when you realize you are not the only one in pain. J
Where do you put the puller on the Whisper crank pulley?
We started the car and everything sounded and looked perfect. The crank pulley had two sets of eyes watching down on it to make sure there was no wobble. Once we were satisfied, we went down the road, found us a nice straight stretch of road, and banged a few gears. With Auto Tap set up and running, we were monitoring the knock retard column with great interest. Imagine our surprise when the same knock retard that was present back in the fall of 2000 was back again almost two years later. There was a brief second when I was about to spontaneously combust.
This time there was more going on than just knock retard. I was also monitoring individual cylinders for misfires (because I had a “gut” feeling). Sure enough, I was kicked in the gut when I saw that some misfires were present in several cylinders. It is possible that the plugs have gone bad after two years of not being changed. A plug change will be added to the “to-do” list. I don’t believe the misfires are related to the knock retard problem, but I have been known to be wrong before, though some time will tell.
In the second article in this series, Time to cool things off a bit, I talked about what kind of people will search out a problem to the end. I said that 90% of people will stop fairly quickly because you inevitably end up in a situation like we are in right now. We almost fell into that 10% category but we decided to continue the search.
What’s the next step in eliminating knock retard? After some discussion and deep thought on today’s results, (Jack giving me a good chew over removing his under drive pulley when it was not the cause :-o ), the pushrods will be pulled and checked for straightness. What are friends for? J
- Eric Barger
Web Author: Eric Barger email@example.com
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Revised: June 07, 2007.