Spark Plug Gap .040" not .060"

[gary350]

New information from GM says gap your spark plugs .040" not .060" as recommended.

My gas mileage has been bad since I bought this vehicle. It was 9 when I bought it and I got it up to 19 buy changing the cooling system thermostat, engine air temperature sensor, air intake sensor, over size air filter, and spark plugs.

Now gas mileage has dropped to 13. Engine seems to be running a little bit ruff like its miss firing the dealer told me to re gap the plug to .040". Gas mileage is up to 15.8. I re gapped them again to .028" gas mileage is up to 17. So far so good. There still could be a problem like it needs new wires.

I'm still having problems with the fuel injector spider it still leaks fuel. I just don't want to pay $770. to have the spider replaced. I will have to buy 128 tanks of fuel to break even. My vehicle only has 110,000. miles if I put another 50,000. miles on it that = 166 tanks of gas if mileage goes up to 18. That is 41 tanks of gas I don't have to buy = about $950. worth of gas saved.

I know a guy that changed his fuel injector spider his gas mileage went up to 24 on the highway and 20 in town. If I get the same mileage that could be a good savings.

 

[lesterl]

You probably want to run 45-50 thou gap, replace the spider with the updated MPFI unit, replace the Cap and Rotor with AC Delco/ Delphi units only.

What plugs are you running?

Spider assembly repair is repairable with single injectors for as low as about $28 for reman poppets, or a whole assembly for $178, the spider can be replaced in an afternoon and pretty easily...... The prices I listed were off RockAuto and for a 1998 since you didn't list your year I just used that as a baseline....

Oh, and his mileage is abnormally high, don't look to get much more than 18 to 20 for a 2wd on the highway.