Where did that "miss" come from?!?: Time to cool things off a bit more

August 6, 2000

Where did this "miss" come from?!?
After a night of racing we set the SES light

A trip to the drag strip was on the schedule so we had to make sure that "good" gas was in the car's gas tank. Race gas (110 Octane) is not readily available in our neck of the woods. This forces us to use what resources we have available to us and that means octane boosters.

Before this bottle of Super 104 Octane Boost was poured in the gas tank we want to give some background information on the history of the previous tank of gas. Super 104 Octane Boost was added to a full tank of premium gas a full eleven days prior to this fill up. We managed to burn five gallons out of the tank before the car got parked for the eleven day period. The car had around eleven gallons of gas in it with a bottle of Super 104 Octane Boost.

Super 104 taking a second to strike a pose

A quick stop to Wal-Mart for a bottle of Super 104 Octane Boost was on the agenda before making it to the track. We thought that the car had sit too long and the gas might have went downhill. With this in mind a bottle of Super 104 Octane Boost made perfect sense.

Two Auto Tap logs were taken out of the six runs down the strip and despite the very humid and hot conditions, knock retard was at a minimum. Everything was looking hunky-dory at this point and we gave no thought to adding the "black bottle" to the gas tank.

The next day we took a short road trip to Nashville, Tennessee. During the 130 mile trek the car was a little rough. There was a short jerk that would show itself from time to time. At red lights you would have thought we had a .700 lift cam installed. The smoothness of the LS1 which we were accustomed to experiencing was gone and was a herky-jerky type of ride. The actions were just shrugged off until we noticed the Service Engine Soon (SES) light illuminate. At this point the car had our full attention and we were all ears. The SES light showed it self at idle waiting on some friends to arrive. We immediately had several theories to what we though was going on.

It looks harmless enough just standing there looking innocent

My first thought was that the spark plugs had fouled because of all the octane boost in the gas tank from the night before. A similar situation had occurred on our 1999 Chevrolet Silverado. The only difference between the two is that it took three consecutive fill ups using Super 104 Octane Boost to foul our plugs. The other idea was that the Magnecore spark plug wires had finally give out. We do not run the metal heat shields on the wire boots and many people have reported that the wires have dried out and cracked from being exposed to heat on the LS1. Since we did not have our computer and Auto Tap cable, we just drove the rest of the day with the rough performance and headed home late.

First thing the next morning we found out that we set two P0300 diagnostic trouble codes (DTC). One was set at idle and another at 68 mph. Using Auto Tap we viewed the Misfire History of all eight cylinders. There were 2 or 3 misfires on several of the cylinders within 60 seconds of starting the monitoring. This gave us strong reason to believe that an ignition problem was present.

At this point we had ran all the gas out of the tank but 4 gallons. We added five gallons of premium gas back to the tank and were pretty confident we had diluted the Super 104 down to near nothing. This time when the attention getting SES light appeared there was no fear because Auto Tap was up and running while taking a short 70 mile drive down the interstate. We set two more P0300 DTC's.

Notice the red color

The next question that had to be asked was, "Should we change back to the stock wires or do a plug change?" We pulled the spark plug in cylinder three and we found our answer. The tip of our plug was red and covered with black gunk! Wow! Off to the parts store to pick up eight copper NGK TR-55 spark plugs. We changed the spark plugs in around one hour and fifteen minutes and enjoyed doing it¹. Our arms would have told a different story.

After the drivers side was completed it was obvious that the spark plugs were probably the cause of the whole misfire situation. The swap on the passenger side of the car confirmed that we had a major problem with the color of the spark plugs. It should be safe to say that red is not the color you want to see on your plugs.

We started the car up and immediately noticed that our car was smooth as silk. A short drive down the road confirmed that we had removed any sign of the miss we had experienced. No more herky-jerky dance moves for our LS1, we were back to normal! Wooo hoooo!

I believe that it is evident that Super 104 Octane boost should not be used in back to back fill ups. Especially if you still have some Super 104 Octane Boost in the gas tank of your car when you pour in more octane boost. You will probably find yourself with a LS1 that runs smooth as sandpaper.

- Eric Barger

Works Cited

1. www.installuniversity.com Spark Plug and Wire Installation