Expert: Skip Bollinger - 1/3/2008

Question
I had a Jasper engine installed in my 1984 pontiac grand prix 5 years ago. I was told that the gas mileage was going to improve after 10,000 miles(breaking in period). This car is fully restored under the hood. I have had everything changed and/or fixed including the catalytic converter. My problem is my gas mileage has not improved at all! I'm not getting any better mileage than before. Is it possible that the mechanic did'nt install it correctly or maybe there is a leaky valve or not sealed correctly? Thanks

Answer
James,
  You ask a question but leave me with a LOT of questions. You neglected to tell me what size engine you had replaced. By today's standards, your GP is a land yacht and very difficult to obtain good gas mileage. I'm not sure why you waited 5 years to begin to be concerned with mileage. Also, you don't tell me if you replaced the long block or just a short block. IF it was a short block and they used your old heads, there could be a carbon build up problem there. Please let me offer these thoughts for some various engines available in your car, since I don't know what you are working with.
  If you have the V-6 3.8, it will be working so hard to pull the weight, your chance of fuel mileage is slim. If you have the 305, your chances are better. With either engine, they are carbureted. Have you had anyone look at the carb to see if it needs to be rebuilt? The V-6 and the 305 both had carbs. Now if you have the diesel 350, that is a completely different ball game. It is fuel injected. It has the old Bosch Fuel Injection and hard to find parts. You might have it just cleaned very well by an experienced mechanic.
  James, Jasper does an excellent job at what they do. I can't fathom there is a problem with their product. They are probably the most expensive mass engine rebuilder but have an excellent quality control system. They are Human so there could be a slight problem but I doubt it. I hope this may give you some direction and good luck.
Skip