Hello, I am a new member and I must say this sight has already proved to be very useful.

My problem started a month ago when I bought my 3rd Ranger. It is a 1995, 2wd, 4.0 liter(V6 4.0 Liter FI - 245 CID VIN X O.H.V.), with a tow package. The CHECK ENGINE light came on and the code read CAMSHAFT POSITION SENSOR. I have located the part on my truck as being:
GP Sorensen CSS137
C:\WINNT\Profiles\jwilliams\Desktop\Part Detail at Advance Auto Parts.htm

I have found the part but it is not the “bottom of the distributor plus a cap” set up that all the other questions in this forum are about. This is a one-piece deal with no where to “put an alignment tool” or “remove a cap”. The part is $388 and labor doubles that.
I have worked on trucks my whole life and this has me stumped.

Questions:
What does this part control?

Where can I find one cheaper? (junkyards are a no go…ive tried over 25 that said they had it, either to expensive or they have the one with the cap)

Why doesn’t any manual that I have mention the part? They all have the one with the cap.

From what I can tell the part is only supposed to control the fuel injection timing, the spark timing is controlled from sensor on the crankshaft.
How do I tell if the truck is a DIS or an EDIS?

Once I pull the part and put a new factory one in how does it get calibrated?

What are the consequences of letting it go and not repairing the problem?

 

In a traditional fuel injected 4-cycle engine, the ignition and injection events of each individual cylinder take place every 720 degrees (2 revolutions) at the crank but every 360 degrees (1 revolution) at the camshaft. On older vehicles, the ignition distributor was geared to turn at camshaft speed so it could be used to identify the correct stroke for the ignition event.

If a vehicle has the early Distributorless Ignition System (DIS) system, it needs a Camshaft Position Sensor (CMP) or a Cylinder Identification Sensor (CID) so it can tell the difference between the intake/compression revolution and the power/exhaust revolution. Half of the plugs fire in the first revolution and the other half in the second revolution.

The so-called Electronic Distributorless Ignition System (EDIS) does not use the cam position sensor to distinguish the first revolution from the second. It doesn't need to know. Instead, it uses double ended coils within a coil pack to fire all of the plugs during every revolution. The spark events occur in three pairs during each 360 crank degrees. For each pair of cylinders approaching TDC, one spark plug is used to ignite the mixture on compression in one cylinder while the other plug's spark is "wasted" on the exhaust stroke of the other cylinder.

Vehicles with EDIS and Sequential Electronic Fuel Injection still need to have some variation of the CMP sensor. Although it is not needed for spark scheduling, it is necessary to synch the PCM timing for the fuel injection events. Since it is important for injectors to fire on closed intake valves for emissions reasons, the PCM needs to know where the crank is within its rotation [Crank Position Sensor(CKP)] and whether it is in the first or second revolution of the 4-cycle sequence [Camshaft Position Sensor(CMP)].

I'm reasonably sure that your 95 Ranger has a 104-pin EEC-V module with SEFI and PCM-controlled EDIS. So, to answer one of your questions, the CMP is there to synch the fuel injector timing.

The gear driven CMP sensors that I have seen on 3.0L, 4.0L and 4.2L Ford OHV V-6s from the 90's fit into the former distributor position. They have a removable sensor on top of the synchronizer body (held by two screws). A special timing tool is used to align the synchronizer shaft to the correct gear tooth position on the camshaft. This is a picture of a V8 CMP but the V6 part looks similar:



The timing tool looks something like this:



If you simply remove the type of sensor in the picture without disturbing the synchronizer assembly (lower body and gear drive), it does not need to be retimed. The timing is the geared relationship between the camshaft and the shaft in the synchronizer housing which turns the windowed reluctor for the CMP Hall Effect sensor.

 

http://www.partsamerica.com/ProductD...pe=985&ptset=A

or

http://www.partsamerica.com/ProductD...pe=985&ptset=A

PLEASE LOOK AT THIS LINK( just control+c it into the web window)...THIS IS THE PART I HAVE IN MY TRUCK I LOOKED AT IT WITH A MIRROR. it is a one peice assembly that has nothing to do with the cap. or alignment tool!!

 

I have never installed that exact type. It sure looks like it has two screws on top in your pictures:




FWIW, I found this information for timing a 95 CMP without the tool:
http://flatratetech.com/cgi-bin/ubbc...ic/26/884.html

 

So can the sensor just be replaced on this or does the whole sync gear unit need to be replaced?

Mine isn't chirping or making any noise but I would like to replace it to ensure no problems in the future.

 

Yes, the sensor can be replaced separately if it is bad. However, what usually fails first is the synchronizer. If you are going to replace the assembly, I would recommend getting OE parts instead of the cheap knockoffs sold at parts stores.

 

Thanks Bob, I think I'll just go ahead and replace the whole damn thing... might as well.