Decreased gas mileage and rougher running engine

[BGbaja]

Recently had head gaskets, valve gaskets, radiator belts, timing belt replaced. Before that gas mileage started decreasing before that with a rougher running engine. The gas mileage was always around 24 to 26 mpg. Now its down to 19 - (23 hwy). I have replaced the spark plugs. The air filter was replaced less than 10,000 mi ago. Any ideas what could be causing this? Or how to fix it? Thanks

[kalins1]

When we had our headgasket replaced, the Baja came back with the same symptoms. It turned out the mechanice had accidentally torn one of the ends of a spark plug wire off. I replaced the wires and she was as good as new.

[BGbaja]

Thanks, I'll give that a shot.

[davecoon13]

Check your fuel filter. Mine was clogged or dirty, and replacing that improved my mileage and engine smoothness. You can get a new fuel filter on ebay for $10, and I have another thread where I found on Scoobymods how to replace it. Pretty easy $10 fix.