ok so i drive a 1990 rs and recently my gas mileage has gone to **** i calculated it at about 12 mpg i believe that im running rich because every once in a while i get a cel for fuel supply system. why would i be running rich and how do i fix it? second. i keep checking my oil and it keep going down just a little. is this normal for a little or am i burning oil?(havent noticed any blue smoke and when i baught it this summer it compression tested perfect) btw 203,000 miles. another thing. when i did a valve adjustment i noticed that the arrows on my cam gears did not point directly up they kindof pointed in toward eachother when its at tdc. looks like on skip a tooth or so. will this cause any problems like say loss of power and fuel econemy? i appreciate any help you can offer.

 

The gas mileage & CEL might be a stuck injector or wrong fuel pressure. Before doing too much, put a bottle of Techron in the gas tank. Then maybe tune-up stuff. How old are you spark plugs or wires, cap, rotor, stuff like that?? After ruling out those easy things, then you can think about FPR & injectors.

If you didn't add oil, how many miles would it take to go from high to low marks on the dipstick. It's not completely perfect, but it's kinda normal for a 200k engine to use some oil. Gotta burn a lot before you notice the blue smoke.

The arrows on the camshaft sprockets are only supposed to point sorta upwards. The REAL timing marks are little dimples out at the sprocket teeth. There's 2 on each sprocket, & they should all 4 line up in one straight horizontal line. I guess you can line them up against the top of the timing belt cover. (This would definitely give you crappy gas mileage.)

 

thanks