2003 blazer gas mileage

[kool331]

I have a 2003 Blazer with 53,000 miles on it. I bought it last year and was getting 17-18 mpg city and 20-22 mpg hwy. Now I am getting 13 mpg city and 18 mpg hwy. I changed the cap and rotor-which were definitely due. A friend talked me into putting split-fires in. I just had the oil changed and new air filter. The engine light has not come on. What could be going on with the mileage? I bought AC Delco plugs-what the manual calls for-and will change them tomorrow and see if that helps any. The blazer runs great, idles smooth, has plenty of power. I am at a loss as to what is causing this loss of mpg if the 'stock' plugs don't make a difference. Any suggestions? It has the 4.3 engine, 2003 LS, 4x4.

[BlazerLT]

1.) Remove split fire plugs, punch your friend in the face and when he is knocked out shove them in his out door.

2.) Install AC Delco Platinum plugs gapped properly.

3.) Ever changed the air filter?

[drdd]

also,

fuel filter, clean the throttle body, tire pressure, and check that a caliper and/or e-brake isn't dragging

dbl check all ignition wires and connections

u got that air filter installed right?

Originally Posted by BlazerLT

1.) Remove split fire plugs, punch your friend in the face and when he is knocked out shove them in his out door.

2.) Install AC Delco Platinum plugs gapped properly.

3.) Ever changed the air filter?

[DINO55]

AC Delco Platunim Spark Plugs gapped at 0.60
New Air filter
New fuel filter
Clean the MAF sensor
Also add a can of good fuel injector cleaner to a full tank of gas. If you follow these tips, your gas mileage should return to normal...

[kool331]

I had the air filter changed when they changed the oil. I guess it's installed right. I check the tire pressure weekly. Thanks for the tips. I'll be checking the brakes, fuel filter, and cleaning throttle body tomorrow. What and where is the MAF sensor?

[paulson]

So split fire spark plugs cause worse gas mileage?

[BlazerLT]

Originally Posted by paulson

So split fire spark plugs cause worse gas mileage?

Thye are just a gimmick seeing spark can only come from one electrode at a time.

Also, they are known to break apart inside the engine.

Just don't use them.