I recently got a 1999 3.0 ranger and the syncro was missing when I got it. The previous owner took the old one out and never replaced it for some odd reason. I trailered it to my house stuck the new one in following a how to, and the CEL has been on for months. Ihave been getting only 12-14 mpg. I have read many threads on hear and it still keeps kicing the engine code.

 

well its obviously close to being in time other wise it wouldn't run. Judging by your gas mileage id say its either advanced or retarded to much you can tweak it a couple degrees either way but eventually it sets a code and then ay farther out it will quite running. id redo it and make sure its at top dead center on number 1 cylinder and then set it again. After that unplug the battery to reset the PCM it will have to relearn the fuel maps and idle.

 

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.

 

Nice catch on TDC ROND i quickly reply and need to work on how through my answers are also nice on the batch fire just recalling when i last did mine which its due again the squealing has started but anyway last time i did it it was off to far and a bad position sense from the computer can also cause a no start (mine did) reset the sensor in correct location and it was fine id agree no sensor would still run but an incorrectly reading sensor will cause problems as well from experience. But also a thing to remember if the previous owner pulled it and never put one back id start looking other places because he may have just given up on it when there were others problems.

 

That would be an odd occurrence for a mis-timed or unhooked CPS to cause a no start, maybe computer software has been changed, not a good change either.

Most, if not all, engine computers are programmed with "fail-safes" in mind, the one thing they try to do is to not strand anyone because of a minor sensor failure, and CPS is a minor sensor.

Outside of a bad CKP(crank position) sensor(major sensor), or a bad computer, any other sensor failure shouldn't cause a no start/no run incident.
CEL would come on and engine may not run at full power but it should still run.

CEL will flash rapidly if possible engine damage can occur but engine would still run until it was "damaged". oops, lol.

So if they have changed this parameter of no start/no run on a sensor failure then, IMO, they need to rethink their strategies.

The CPS was added to improve MPG and to get more precise spark advance, fuel injected engines worked for many many years without them, and while they do make for better engine efficiency, the CPS is not a critical system by any definition.

EDIT:
Now thinking about the cam synchronizer as a whole unit.......................they may have looked at it as a "virtual" oil pump sensor, it would be an odd thing to do but never meet a software writer that wasn't "odd", lol.
So no CPS pulse on cranking "assumes" no oil pump, so no start.......................it's a stretch, but could have popped into someones mind to add as a failsafe

 

Yeah thats what I'm thinking because when it started going the symptoms progressed from squealing to random stalling so I'm guessing they did add the failsafe for the oil pump which would explain the stalling from intermittent signals and the no start after replacing it incorrectly. But half the ideas these engineers come up with seem to only benefit them haha. Who knows maybe a code writers joke lol.