I recently had to replace the oil dipstick tube...to make a long story short, I broke the pointer gear on the harmonic balancer.....aka...the throttle position sensor.......I ordered one from a junkyard which matched up at least to my eyes perfectly. I put truck back together and now have misfires on #1,4,6 cylinders.....I have done some research....and am wondering if the cam position sensor could need reset....could the crank position sensor be different? It was keyed and I replaced it just as the other cps....are these harmonic balancers, tps, pulleys all the same for a 4.2 liter? What else could cause this misses...the truck ran fine before I replaced the dipstick tube..the only thing that has changed is the timing. Is this a difficult fix? I am kind of at a loss.

Chris

 

this is a 2000 f150 4.2L

 

I recently had to replace the oil dipstick tube...to make a long story short, I broke the pointer gear for the crank position sensor on the harmonic balancer.....aka...the throttle position sensor gear(pointer).......I ordered one from a junkyard which matched up at least to my eyes perfectly. I put truck back together and now have misfires on #1,4,6 cylinders.....I have done some research....and am wondering if the cam position sensor could need reset....could the crank position sensor gear not be exactly mounted like the original... be different? It was keyed and I replaced it just as the other cps....are these harmonic balancers, tps, pulleys all the same for a 4.2 liter? What else could cause this misses...the truck ran fine before I replaced the dipstick tube..the only thing that has changed is the timing. Is this a difficult fix? I am kind of at a loss. I get the feeling that the only thing that has changed is the harmonic balancer(gear pointer?).....I don't know if it has the cam position sensor...the truck is at my other house...but it would make sense if the crank pos. sensor is a little off than the cam sensor would be off also. what do you guys think? Distributors were sure a lot easy to deal with in a jam!

Chris

 

Lets clean up the designations first.
Don't run the throttle position sensor in with the crank position sensor because they are not the same nor even in the same area. It just causes confusion interpreting what your saying.
The crank sensor toothed wheel and sensor mounting are fixed positions and non adjustable.
Next if you had the cam position 'fixture' out, it has a spec setting.
The cam position times fuel injection.
Next, if the motor starts there is no issue with the crank position sensor location.
.
Since you only seem to have an issue with 3 cylinders it's not the crank sensor or the cam position sensor.
You have some issue with the ignition for those cylinders.
The coils, the plug wire placement, the plugs etc.
.
If your referring to ignition timing being out of spec, unless you measured it, it just guessing and would not affect just 3 cylinders out of 6.
Good luck.
.

 

thank you for the answer. i kept getting the crank position sensor, and cam position sensor mixed up. the cam position sensor controls fuel to the rails as i understand. the cam position sensor was not pulled! now i am confused.....what could i have done to effect the ignition timing? i have a list of the sensors code (obd-02) but they are 15 miles away. I recently threw and upstream o2 sensor code....maf and another 02 sensors as possible causes. basically, I dropped front differential, removed oil pan, replaced oil dipstick tube...i had to remove, radiator, shroud, and damaged harmonic balancer which i replaced with a salvage yard part.....did the harmonic balancer....which seems to fixed in position, vs the cam position sensor which can be adjusted seem to be the problem.

 

bluegrass....reread your post. it makes a lot of sense what you are saying...3 cylinder misfire...cps fixed position.......ignition problem was my first guess also......i will look for and old timing light or check somehow if i am getting spark at these 3 cylinder...where/what is the next step to check?

 

merged threads, one thread per subject please