alright, so my bro has a 1995 dakota with 318. recently the fuel economy dropped from 17 to below 10,dad says the exhaust smells rich of fuel. its at 200k miles. its caught up on everything. thats about all i can say.

 

what can the possible probems be?

 

what do the plugs look like? the plugs are the window into your soul er chamber.

 

you should check if your O2 sensors are functioning properly. The rich fuel smell coming from the exhaust may be a bad sensor.

 

can also be vacuum leaks, more air = more fuel, plenum gasket is well known issue with these trucks again more air = more fuel

take passenger rear plugs out usually they are worst, also can look down throttlebody and see if you see oil pooling any .

 

ok, so i redid the plugs within the last 10k miles they where champion coppers , didn't mess with the wires honestly, i looked into the cap n rotor and while i was contemplating upgrading it dad just sanded the old stuff off and it was reassembled, i put a k&n air filter in there and it increased my mpg from 15 to 17 before the sudden drop., my cousin says it could be a dirty throttle body, i didnt think the o2 sensors could have that much affect on a truck that old, but I'll check it out, and i also think the good ol catalytic converter could be on death row.

 

Look for oil in the intake. The plenum gasket may have blown. There is a TSB on it. If you go the regular repair route it will happen again but its 200K so????? Hughes Engines makes a permanent repair kit with a 1/4 aluminum plenum replacement for the factory steel plate which is the cause of the problem. Get new intake bolts if you do that. My mileage has gone from 9mpgs to 17+ I also did all new sensors including EGR and O2 and wires cap rotor coil and switch plate.