P0340 Camshaft Position Sensor Circuit Malfunction -help

[Andy Cabrera]

This morning, went to start the truck to go to Walmart. She cranked and did not start (as usual) I turned the key and cranked it again and she sneezed and didn't turn over. I thought nothing of it since this is common for this truck ( I know fuel pump)

So...

I crank her up and she is bucking & wheezing and the wife said puffing black smoke from the tailpipe. She won't stay on unless I paddle the gas pedal. Finally my Scangauge 2 came back with DTC codes



P0340 Camshaft Position Sensor Circuit Malfunction

P0755 Shift Solenoid B Malfunction

P0000



Ok so I am dismissing the P0000 for now

I am assuming the P0755 is due to the truck is bucking and since the dash idiot lights are on and off I will assume this code is an aftereffect (since the truck is in park).



That leaves me with the P0340. Assuming for the time that my timing chain didn't slip a tooth, I assume the culprit is the Camshaft Position Sensor.

I bought the part at Autozone for $30 so I was happy that I didn't have to drain my son's college fund.

I replaced the sensor. I found a picture online

It's right on top of the front driver's side valve cover.

& since it only took 3 minutes to do I figured I'm screwed.

I still have the same problem as above. So am I correct to assume the timing chain slipped ( since it will still run really rough)?

 

[Andy Cabrera]

UPDATE



Unfortunately my Ford shop Manual doesn't give me the checks.

It refers me to the "Power-train Control/Emissions Diagnosis (PC/ED) manual.



This nightmare just keeps getting worse!

Would anyone have the voltage checks for the cam positioning sensor harness?



I just hope this isn't the timing chain.

 

[Steve McKellop]

You have mail.

 

[Andy Cabrera]

Ok so today I farts around with the Trac.



I repositioned the CPS

I cleaned the MAF

I cleaned the IAC



Although the truck won't idle, I cannot get the truck to throw a code. When I start it I can keep it running by pressing and holding the gas pedal. It WILL stay running although the idle goes up & down ( 1500 - 3000 rpm ) while holding the gas pedal down. If I release the gas it stalls.



Now it sounds like the IAC so I removed it & checked it while removed from the TB but plugged in. I turn the key to on the IAC opens and after a few seconds closes. I put 12v through the IAC directly during bench testing and it stays open.

On my BMW when it went it would idle by itself but the rpms would climb to 2500 then drop to 1000rpm, but never stall. I don't know if the Ford works differently.



A thought on my part. Is it possible that the fuel pump doesn't have enough pressure to run the Trac? It is working since It keeps starting but would lack of proper psi cause the above issues?



One other thing, I hear a whirring sound from the area of the TB. It sort of sounds like a supercharger or the sound that a bad torque converter makes.

 

[scott degroot]

Pull a plug and check the compression, if the timing chain jumped a tooth the compression should be low. A fuel pump not putting out enough pressure will definetely keep the vehicle from starting or starting and not running right.

 

[Andy Cabrera]

At the risk of over thinking the problem I handed it over to the good people at the AAA car care center. They told me the cost to diagnose the problem would be between $50 & $99 dollars. (I didn't expect $50) I figured they have the equipment to figure this out better than I (plus I'm lazy & I got fed up)



Everything checked out perfect except the truck was running lean. No DTC codes were thrown, nothing! They found the infamous "ELBOW' was very soft & the PVC valve was shot.



They swapped it out and all is now well in the world... ok except my wallet that's $300 lighter. as much as it pisses me off, I have to admit I would not have found it,...at least not this fast!



Tomorrow I think I'll make myself feel better & work on my '63 Mercury.