Triubleshooting missing cylinder
 

Hey, fellow Sl Owners: I had a problem with rough idling and low power and could not isolate the problem. Finally I hit upon an idea that proved VERY worthwhile. I bought an Infrared sensing thermometer with a Laser pointer. When I read the temperatures of each cylinder at the closest point to outlet from the cylinder head to the exhaust manifold I found that I had NOT one, but TWO cylinders that were running WAAAAY too cool. They were running at a temperature that was about 200 degrees Farenheit BELOW the cylinders on either side of them, so I didn't have ONE bad cylinder, I had two adjacent ones that were not running properly. I then ran a compression check on all the cylinders on that bank and found that all were within a narrow range that indicated GOODE compression. I then ordered two fuel injectors and the associated rubber boots. After I replaced both injectors I again have ALL EIGHT cylinders firing properly and the temperature reading are all fairly close to each other. Note that the rear cylinder on BOTH banks will always read somewhat HIGHER than any of the others. I hope this will help someone else who has a problem with rough idling and poor power. I bought the Infrared thermometer on sale for about $28.00 and I feel it was worth ten times that much in labor charges that I didn't have to pay.