Reinstalling Cam Shaft Postion Sensor .

[Justinwht]

SOLVED.

Been on forum several years and should post info on my three Explorers. '95, '95, 00.

At issue is 2000 4.0 OHV, standard shift, 150K miles. 21 mpg highway and 19 in town.

Few months ago at highway speed, the engine missed once. Last month it missed a few times at 40 mph. Last week it ran rough in parking lot and stalled, but restarted immediately. This week it started missing, drove a few hundred feet and finally stalled in parking lot. Was able to restart and drive home.

Replaced fuel filter, probable the original and fuel in filter was black, yes...black.

Engine starts, good acceleration when I floor it, but when moving slow in parking lot it wants to stall when PRMs drop from normal 800 to 400, so I give it more gas. The stalling at low RPM I found (on this forum) a symptom of sensor problem.

Had the truck a year and Engine light stays on and error code (not recall) said cam shaft position sensor error.

Right now getting several error codes.

P0340 - Defective Camshaft Position Sensor
P1309 - Misfire Detection Monitor Not enabled
P0171 - System Too Lean Bank 1. This may be caused by misfires, and not really a lean fuel problem.
P0174 System Too Lean (Bank 2). Same as above.
P0455 Evap System Large Leak Detected. Might be caused by bad sensor.

All four errors refer back to a cam shaft position problem.

I pulled out the suspect sensor, ohm meter shows 593 ohms; compared to 698 ohms for new one.

WHAT TO EXPECT ...
On SOHC its behind engine on driver side, on OHV on the passenger side. Need 5.5 mm ignition wrench.
As the bolt comes out, the wrench will slip past the head, so use thumb to feel the wrench stays on head.

The sensor wants to rotate when placed back in. The shaft assemble has a keyway that will match the sensor electrical connector and screws holes would be aligned.

SOLVED ...
Engine now idles at 1,400 RPM for about a minute after clutch pushed in, then drops to 900-1,000 RPM. No more stalling when RPM drops to 400 RPM driving in parking lot.

 

[koda2000]

On the SOHC V6 the cam position sensor is located in/on the valve cover. It is located on the rear of the engine block on the OHV V6 engine and on the front on the engine on the V8.

 

[Justinwht]

Yes. On the OHV it's half way down vertically and a tad towards passenger side from center. You can see it with flashlight and mirror - between the lines above it. I had to stand on footstool, aka cinder block to reach it. Easy to feel for it.

Update...The Engine light hasn't come back on, no error codes, just the expected INConclusive tests of emissions control components - evap system, etc that will clear to OK after driving half an hour to an hour.

/added
'96 4.0 L, SOHC, auto, XLT, 160K --- '00 4.0 L OHV, std, 150K, XLS --- '96 4.0 L, SOHC, auto, XLT, 190K;
/added - all are 4WD

 

[Justinwht]

Nope... Still drops to 500 after idling a min. Drove around parking lot several tines.
P1309 - Misfire Detection Monitor Not enabled
P0171 - System Too Lean Bank 1
P0174 - System Too Lean Bank 2

 

[Justinwht]

My immediate concern is will everything go south suddenly. I can tolerate a lean running engine and reduced gas mileage power for a week; but if the cam sensor not reporting engine RPM to computer, will it turn off the fuel injectors if it assumes the engine isn't running.

 

[massacre]

I drove a lean running engine for a long time and it makes it run hot and eventually I had to replace the heads due to cracking and bad gaskets. Mine was ohv though not sohc.
This took years to happen and the truck still ran, but not well.

 

[Justinwht]

That's helpful to know. Of course I don't want to cherry pick the most opportunistic predictions and ignore the problem.

I may eventually get a catalytic converter code (P0430 I think), that will be a collateral symptom of running lean, which falls back to the cam sensor (or power control module).

I'm not ready to blame the PCM yet, but it might get there. That's a thousand dollar part I can find in a low mileage Explorer in junk yard.

 

[Justinwht]

Drove around in traffic for an hour last night. No problems, but engine dropped to 400 RPM at stoplights; so had to hold pedal down to keep RPMs up.
I don't think it's a coil pack problem - if it was a bad coil, then the companion coil would not work and means a one third loss of power. It still launches fast from a stop up to 3,000 RPM with power to spare. That could not be accomplished with bad coil packs.
As long as I can still get around for another week until I can find the problem, I'm fine with that.
>>>>> Just don't want to crash and burn without warning.

 

[Justinwht]

It crashed and burned. Had no problems last or today, drove about 20 miles. Left parking lot and drive few hundred feet and bucking back, could barely make it back to parking lot. Won't turn over.

Ok.. waited a bit. Started right up, kept RPMs high, drive a couple hundred feet to parking lot I hang out.

Going to think this over.

FML

 

[Justinwht]

Checked code this morning. Still the
P1309
P0171
P0174

But a new one.
P0320 - Ignition / Distributor Engine Speed Input Circuit

/Added update
Just tried starting truck. No start. Oops..forgot to push in clutch. Duh. My bad.

Truck started. Tried to stall. Kept RPMs high to keep from stalling. Let run half a minute and shut it down.

 

[massacre]

Might be time to do some tests, check out that circuit.
If I remember right my Mustang threw a engine speed sensor code and it was for the crank sensor. Maybe your truck is trying to tell you that your cam and crank are not communicating properly?

 

[Justinwht]

Yup, going to replace the CRANKSHAFT position sensor, only $16.

Tentatively ruling out:
Intermittent fuel pump - Been down that road before and not acting that way, I can floor it and it takes fast.
ECM - I'd probably see a lot more codes getting thrown up. BTW, may be hard to find one in junk yard. I have the OHV engine. Going to call around with VIN code that shows the engine model.
Fuel filter - already replaced
Cam shaft position sensor - already replaced that.
Bad coil pack/s - That would mean a one third loss of power, not stalling completely.

 

[Justinwht]

Forgot to mention this. The cam shaft sensor was rotating, ever since I first looked at it a year ago. I know you have to use a tool to properly align the shaft if you replace it, but this is just the sensor that drops into a keyway to keep proper orientation.

 

[Justinwht]

Replaced crankshaft shaft position sensor. Idled at 1100 for five minutes. Restarted and ran a minutes thn RPM stopped to 400 and wanted to stall.

Cleared the codes, drove few minutes to bring engine to running temperature. No problems.

But P01309 reappeared. Misfire Detection Monitor Not enabled

 

[massacre]

There is a way to check the alignment of the cam synchro. Not sure if it is the same procedure for your truck but basically you put the crank at TDC after compression stroke cyl #1. Then install the synchro, tightening the hold down but keeping it loose so that the housing will pivot left and right.

Then advance crank 34mm more as measured on the harmonic balancer.

Then backprobe the middle wire of the cam synchro harness connector with the sensor plugged in. Turn key to on position. Turn housing clockwise until there is 0v reading. Then slowly turn housing counter clockwise until battery voltage just shows, tighten hold down and that should be set up correctly.
Then if the test shows something is off, at least you know you aren’t just throwing parts at it?

 

[Justinwht]

If the cam shaft was truly misalgned, the engine would not be running stable for past 18 months, there isn't a bracket or anything that could be loosened (the shaft stays aligned with bushings and mates to a companion crankshaft gear), and the shaft and bushings likely ok as no noises and if really damaged the low RPM and stalling would be consistent across all RPM ranges

I'm going to default ECM by pulling battery cable and rotate the sensir to another position as per my drawing above.

 

[massacre]

Awesome hope you find it

 

[Justinwht]

DidvonnDisco battery an hour while relacecr battery cable terminals. Started rough and almost stalled - possibly ECM was trying to load defaults. Drove ten minutes, still feel right, but no codes. Drove later on five minutes.
P0174 System Too Lean(Bank 2) appeared.

Going to rotate the sensor as shown in drawing next.

 

[Justinwht]

Cleared codes, driver five minutes.
P0171 running lean
Was cleaning tools and can of CRC MAF cleaner was there .. got to thinking a dirty MAF can trigger the two lean codes.

Nope...P0172 and P0174 reappeared.

Searching this forum for clurs.

 

[gmanpaint]

Have you checked the lower intake gasket?