My father has an F150 4.2L engine. It is a 1999. It started backfiring and eventually stopped turning over all together. He has checked the fuel injection system which seems to be working. He has also changed the Ignition Coil thing (sorry i'm no mechanic). He now wants to try changing the CrankShaft position sensor. Could someone tell me the easiest way to go about this or if there might be something else he can try to get his truck going again. He likes to just poke at it till it starts working but I am trying to save him some time and money. Any help would be greatly appreciated.

Thanks
Cari

 

makes no sense to replace random parts. is it throwing any codes? thats where id start. and if the cps goes, it will usually still run

 

Can't do that these days with computerized powertrain control. First thing that needs to be done is scan the OBD2 system for fault codes. Tell him to spend $20 for a code reader before he shotguns any more parts at it.

 

Alright gentlemen and ladies. I purchased the OBD II scanner recomended by you all. We followed all the instructions and got "No Codes". The only thing it indicated was that some of the I/M systems were not ready. These included the CAT, EVAP, O2S HO2S, EGR. I don't know if those matter or not as again...not a car gal. What is our next move any help would be appreciated.

Thanks!
Cari

 

If you disconnect the battery, it clears the memory and there has to be some drive cycles for the sensors to achieve readiness. That's why you have to scan for codes BEFORE disconnecting the battery. If it won't start, unfortunately you are now back where you started.