2002 Sporttrac 4.0 ltr. Engine spits and sputters during acceleration , has a miss idling off and on. New plugs, coil, injector in one cyl., compression is ok. Last dtc code said throttle position sensor. Did a voltage test on sensor. supply 6.9 volts (read it should be no higher than 5) return signal voltage range 1.55 ---6.9 high again but increases smoothly through range as throttle opens and closes. Would the high voltage supply cause the spit and sputtering and why would it be high.

 

A short to voltage will cause this.

 

Thanks Hanky By that do you mean another power wire is shorting extra voltage into the supply line. Do you think this could cause the problems I described.

 

I don't know if it could cause the problem present, but there is a path for higher voltage to get into the reference voltage that is usually in the 5 volt range. If you compare the voltage available to the MAF sensor it should also be in the 5 volt range. If not, then the short to power is before the sensors , if not it may be confined to the TPS wiring.

 

IF I SPRAYED SEAFOAM engine injector and throttle body cleaner (NOT SURE IF THAT'S THE CORRECT SPELLING0 in the air intake tube where it could pass through the MAFsensor would that hurt it and could it be cleaned with MAF sensor cleanor. I've been told the MAF sensor is bad but I'm pretty sure it wasn't before.

 

One thing you can try is to unplug the MAF sensor and see if it makes any difference. You will get a C/E lite , but that way you take the MAF out of the system. If you correct the problem with it disconnected , the MAF sensor is considered defective.

If you do have to replace it , get it from a Ford parts dept. There are lots of problems with rebuilt and some aftermarket sensors.

 

There was an oil leakage near to the engine. I can't identify place, whether there was a leakage in the engine or from any other place.