So I picked up a real nice sebring for dirt cheap, another shop in town told her it needed a huge list of things, some it needed some it didn't. It came to the other shop because of a no start issue, they told her it needed a fuel pump as well as all the other stuff, she didn't want to put any money in it and the shop told them about me being a mopar nut so she called me and I bought the car, through a fuel preasure gauge on it and 55PSI. Checked for codes No codes. Checked for spark and it was real intermitant so I through some coils on off a 2.7 I replaced a while back and same thing, swapped in used crank sensor, same thing, swapped in used cam sensor same thing, unplugged cam sensor and car starts right up and runs perfect so I order a new one and while I am waiting on it to get here I replaced the water pump because it was leaking horendously, still runs good with sensor un plugged, new cam sensor gets here put it in and car won't start, un plug it and all is well I am getting a good 5v signal to it, what to check next?

Don't you just LOVE these pure E-cars ? ...!!

Time for a 360 and a TQ !

It sounded like at first you had a bad sensor taking down the 5volt reference. But you put a new sensor in it, so i figured that would have solved it. However, with the sensor plugged in, do you have 5v key on, engine off????

when you unplugged it did it set a Cam Sensor Circuit High code? (I am assuming you have a scan tool) What about if you short the CAM signal circuit to ground does it set Cam sensor circuit low code? that would test both of the other circuits if so.


Let me know on this stuff, and have someone check Tech bulletins if you can.

justin

What engine? I have seen that happen when timing parts have been changed or wrong tone wheels installed between sbec and ngc pcm's. Did other shop make any repair attempts?

No codes come up with the sensor plugged in, I think it was P0340 when I unplugged it but it was definately a cam sensor code just not sure of the number. Of course the CEL is stuck on with it running.

I tried the computer from a 99 intrepid with the same 2.7 and it runs the same way.

The signal wire is not open or grounded, I checked with it unplugged from the ECU.

I did not ask the other shop if they did anything to it yet, I don't think they did. The engine and trans bolts all look un-disturbed so I don't think there was any engine swap going on. I pulled the valve cover back off to make sure the tone wheel looked ok and it was real close to the sensor and no bends nicks dings... I had one from the old 99 intrepid engine and they looked identicle so I think it is ok.


I checked TSBs on alldata and could find nothing. I even tried Google with no luck

I will check the wires like you said in the morning. The one that went to the ECU ground I did check already and it was a good ground with the key on and nothing with the key off.

One other thing that may be of use to know is when I start the engine then plug in the sensor it keeps running.

I have a Mac Mentor scanner. I can not find anything in the data stream or test section about the cam/crank relation or cam signal at all, mabey someone can tell me how to get to it in there

Post deleted by Scottmon

Has the eng been replaced ?? Seen this before and the car had an eng replaced and even though they were the same eng the replaced eng had a different cam gear on it. Mopar went to a different cam gear on certain years with the slots at different spacing for the cam sensor and the PCM knows this. Basically they changed the cam sensor readings the PCM counts. We had this on a 2.7 eng a few years back. The cam sensor only needs to be looked at while cranking on some of the Mopar systems and once the eng starts the PCM dont look at the cam sensor anymore as once its running the PCM knows the firing order and when #1 is at comp once it looked at the cam gear. When it dont see the cam reading alot of times the PCM will just try firing orders (as cam sensor tells when #1 is on comp) until it gets it right and starts. I would look real close to see if the eng has been replaced with the wrong year eng. Basically Mopar used 2 types of ign-fuel circuits on the 2.7 and you have to have it right to work correct. We had to replace the eng in the car we had as even though it ran ok with the cam sensor unplugged it would eventually set a code and the car would not pass emissions like that. Ron

So I just talked to the other shop, original engine... they did spark plugs and oil changes, she was religious about bringing it to them for every thing. They were aparently in the middle of an intersection, car dies and was towed to the other shop where they told them it needed a fuel pump then I go the call about a cheap car.

Could the timing chain have jumped and caused it to not start but still be able to run fine with the cam sensor unplugged?

wldtm I checked to see if it would set cam sensor low and high codes and it did both, testing just like you described. No TSBs in alldata or shopkey.

Any one know how much compresion they usually have? I am getting 150 PSI across the board and wondering if the cam timing may be off one tooth even though it runs great with the sensor unplugged. Mabey if the computer sees them out of sync it cuts spark to avoid engine damage

then it sounds like all three wires and circuits check out ok. put a vacuum gauge on it and see what manifold vacuum is.

we has a 2.4 dohc in a stratus off 1 tooth and it ran like dog crap. had terrible vacuum, and it was only one tooth.

i think you are on to something....

Yes I do believe you are on to something there. You will have to pull everything back apart to check. I have seen this happen if the chain tensioner is not reset properly, it can cause chain to move on initial start up. You know about the different colors on the timing chain right? and their orientation?

So I pulled the valve cover and rolled it to TDC and the chain was one tooth different than the bad 2.7 I have in the floor so we pulled the chain off and reset it with the colored links and it fired off and ran perfect at the first touch of the key. Now after driving it for a while it has developed a rattle from the timing chain cover, guess we will put in a new tensioner tommorow