'00 5.0 cam position sensor voltage questions (p0340)

[Dylan Rodriguez]

The ignition is triggered by the crank sensor, which can shift when the balancer rubber loosens. The Cam sensor signal is "compared" to it. Did you use a new balancer?

No sir. But the machine shop balanced the rotating assembly to my flex plate and balancer so if it were problematic I'm sure they would have let me know. Haven't noticed any vibrations or anything. I was going to order a new crank sensor just for kicks. Also a new sensor cap for the cam sensor. Are you able to check voltage at the two wires on the cam sensor by chance? By comparing these this would let me know if my ecu is bad or not. I'm seeing very minimal voltage on the two wires Key on engine off

 

[Turdle]

No sir. But the machine shop balanced the rotating assembly to my flex plate and balancer so if it were problematic I'm sure they would have let me know. Haven't noticed any vibrations or anything. I was going to order a new crank sensor just for kicks. Also a new sensor cap for the cam sensor. Are you able to check voltage at the two wires on the cam sensor by chance? By comparing these this would let me know if my ecu is bad or not. I'm seeing very minimal voltage on the two wires Key on engine off

I have never heard of a failing PCM on these trucks. I think you are going down the wrong path.

edit. How was the cam swapped without pulling the cam synch? I really feel it is 180 out--

I might lead people down a wrong path once in a while, but when you ask for suggestions, then assume stuff and ignore suggestions, you will get nowhere. I apologize in advance if i waste any of your time, but We are not going to assume the same things you do and would like to have things verified. That's all. Good luck.

 

[Dylan Rodriguez]

I have never heard of a failing PCM on these trucks. I think you are going down the wrong path.

edit. How was the cam swapped without pulling the cam synch? I really feel it is 180 out--

I might lead people down a wrong path once in a while, but when you ask for suggestions, then assume stuff and ignore suggestions, you will get nowhere. I apologize in advance if i waste any of your time, but We are not going to assume the same things you do and would like to have things verified. That's all. Good luck.

I'm by no means ignoring suggestions, please don't think that. I stated that I was going to check the cam sychro with timing light with the cap off, just trying to further eliminate things on this circuit as well as trying that. Only reason I'm thinking ecu problem is I had an issue with my fuel pump relay clicking rapidly last year, couldn't find anything wrong anywhere. Tested all connections, swapped relays, same problem. Tried re flashing the tune, same thing. Disconnected harness from ecu, let it sit for a few days, problem fixed itself. A few days before then, I was on a dirt road, and whenever I'd hit a small bump, it'd lose power. CEL would flicker once when it lost power, (like when you just turn the key to ignition and the cel illuminates but goes away when the engine is started), engine wouldn't fire for a second, then it'd go on running fine, not needing restarted or anything. Would just have a hiccup for when it lost "power" or whatever was going on. Lead me to believe there's a loose connection in the ecu somewhere, but then again it hasn't acted up since then. This isn't a stock ecu, it's a refurb one I bought off ebay and the dude flashed my vin from the ranger on to it and made sure the PATS systems were the same as stock ecu from the v6

There's around 1500 miles on this build since I went the 347 route. Has ran fine until a few weeks ago until that code started showing up. I would totally understand thinking its 180 out if it's been acting like this since day 1 but I've driven it for a few months with everything how it is and hadn't thrown the code

 

[Turdle]

Ah
I had this issue also, turned out to be bad connections in the power distribution box. PCM and fuel pump relay lugs inside the box.

I fixed it by removing the yellow protecor panel so I could get to the lugs to tighten them with hemostats, then, gave a slight twist bend to all the relay prongs for better bite into the lugs.
It was lke the PCM would just die, and with no PCM power the fuel pump won't run either.


You might try a wiggle test to the relays to see if you can duplicate the symptom.

 

[Dylan Rodriguez]

I'll double check all of those. Problem hasn't come back in over a year but maybe I temporarily fixed it with the repeated relay switching. Haha. Got another cam synchro and sensor ordered. Will be here Thursday.

Also when it was doing the relay clicking, the CEL was flashing in sync with the fuel pump relay clicking, and the Theft light was flashing as well. The theft light speed was different than the relay clicking and the CEL flashing though. Tried my other key, still same problem at the time. Thought it was something to do with pats but after disconnecting the harness, everything was fixed so I left it alone.

 

[Dylan Rodriguez]

Hey all. Went through and changed cam sensor and cap, changed crank sensor also, same code. Reset TPS to .78v and idle is better. Will usually stay running fine, sometimes needs a little help on first startup.
Seems like problem occurs when decelerating, truck will have slight hiccup, drop rpm to say 500rpm then quickly recover to ~750-800rpm. Every so often it would have a slight fluctuating sound on very very easy accelerating, not quite a hiccup but something different than normal for sure. Had a slight hiccup once when cruising at 50mph and converter locked up, dropping rpm's. Dropped, then had a small hiccup. Couldn't get it to replicate issue again. Seems to run fine when you're on the gas or leaving from a stop at a little faster than normal rate. Not sure what else to do. Wire looms look good, not crushed anywhere, no burns spots, no open wires, just had transmission out last week changing converters, had upper intake off and inspected harnesses. All seemed well. Really getting discouraged over this damn code.

Only thing left on that circuit to change is the ECT sensors and connectors; already changed coil pack ground to an even more solid connection to harness, don't think coil packs would be bad as that would cause a very noticeable misfire. They have maybe 6k miles on them. Plugs and wires have maybe 1500mi