cam sensor?

[LCAM-01XA]

A fella on my fullsize Ford board mentioned today that his boss has a truck powered by a factory-turbo Navistar, and that it has a cam sensor of some sort that goes out about every 6 months or so. Here's how he describes it: "When the cam sensor goes out on this truck, it won't run. You can drive it, and the engine will just shut off. You have to push in the clutch, start it again and it'll be fine for about 30 seconds, then it'll die again. Maybe it IS for the tach, but it's also sending a signal to the engine computer or something, and is shutting off the motor. Not sure what all there is to the Navistar." Any ideas what that cam sensor is, and why does it kill the engine?

 

[FordGuy100]

Cam position sensor, or CPS, is a powerstroke thing. IDI's dont have them, I'm pretty sure on that.

CPS's are a weak point in the OBS PSD's. There is no real fix for it, once it goes out, you have to replace it.

I have no idea what it does, but they go out on them, and once they do, you have to replace them.

As far as I know they are like $80. We only had one go out on our old 95 PSD, in about 100K miles.

 

[LCAM-01XA]

Aight, so you think they got the two 7.3 engines (Navistar and PSD) mixed? Makes sense..

 

[FordGuy100]

Aight, so you think they got the two 7.3 engines (Navistar and PSD) mixed? Makes sense..

I think he got them mixed up, but just an FYI, both the IDI and all PSD's are made by Navistar/International.

 

[6.9poweredscout]

the CPS tells the i/p when to fire the injectors, at least i'd assume b/c an Cps on a gasser tells the coil packs when to fire the spark plugs. i reads markings on the flywheel.

-Jon

 

[LCAM-01XA]

Yeah, only our engines are mechanical injection, so they are linked to the cam just like a distributor is in an older gasser.

 

[FordGuy100]

the CPS tells the i/p when to fire the injectors, at least i'd assume b/c an Cps on a gasser tells the coil packs when to fire the spark plugs. i reads markings on the flywheel.

-Jon

That is what I would think it would do. Tells the injector driver module (IDM) when to fire off the injectors. Whatever it does, obviously it needs to work properly otherwise the truck wont run

 

[LCAM-01XA]

Right, guess that makes sense now, I take it the PSD uses a common fuel rail with electronic injectors - kinda similar to a SEFI gasser?

 

[Russ]

Right, guess that makes sense now, I take it the PSD uses a common fuel rail with electronic injectors - kinda similar to a SEFI gasser?

Correct(common fuel rail in the heads) the PSD injectors also use high pressure oil to to force the fuel into the cylinders.

 

[BROWNIEBOY525]

there is a recall out right know on i think 1996 - 2003 replacing the cam sensors. The new price of them is like 15 bucks the new ones are supposed to last longer or something

 

[lotzagoodstuff]

Everybody I know with a Powerstroke keeps a cam sensor in glovebox as they are notorious for dying and easy to swap.

 

[BigRigTech]

The IH 466E engines have the same issue. I keep a 466E cam sensor in my road-duty tool box for IH service calls with the start/idle/die symptom....The 466 are to be checked with a dial indicator through the cam sensor hole to see how much the cam is walking back and forth in the block and then they are "supposed" to be shimmed accordingly to spec...Maybe the PSD is the same? Just like an ABS wheel sensor fault for "air gap too large".