Just FYI, there are two TDCs on a 4 stroke engine, compression TDC and exhaust TDC, when setting up CPS you need compression TDC.
Engine will start and run without a working Cam Position Sensor(CPS), the cam syncro shaft housing(lower part) needs to be installed so the oil pump is working.
Computer does a "sanity check" when engine starts, CPS pulses are part of that test, if CPS pulses are missing or just not "in time" with CKP(crank position) sensor then computer runs injectors in Batch Fire mode, on a V6 this means 3 injectors open at each "firing", it alternates the 3 injectors, this keeps the intake full of fuel/air mix, similar to a carb, Batch Fire was the first method of fuel injection(my '94 4.0l is batch fire), so MPG wouldn't be that bad, it is just that Sequential Fire gives better MPG.
I would get ALL the CEL codes in memory, there will be other issues, since you do not have a history with the truck/engine, that would be my first step.
Clean the MAF sensor, that sensor has a big effect on MPG.
Make sure engine temp is running at just below 1/2 on the gauge, low engine temp sucks down the fuel.
Does engine idle start high when engine is cold, about 1,000 RPMs?
And then slowly drop to 750 RPMs after 5 to 10 minutes, when engine is warmed up?
When new, the 3.0l in a stock Ranger was only 16/17mpg.
Also run some Seafoam, or similar gas treatment, in the gas tank, this will clean the injector tips, dirty tips causes fuel to drip instead of spray, this lowers MPG because computer runs engine richer to compensate.
Last edited by RonD; 03-18-2014 at 10:20 PM.