Changed Timing Belt Now Code P0340???

farmer_andy · #1 01-03-2007, 05:42 PM

I changed out the timing belt on my 99 ZX2 after it broke. Went through the procedures I found on this forum and all went well. Motor started right up and sounded good. Drove fine until 2 days later when the check engine light came on. Used my code reader to get a P0340 code which states Camshaft Position Sensor. Does this mean the belt could be off 1 tooth? Should I replace the sensor? I erased the code and it came back on 2 days later. Any suggestions? Thanks. Andy....

Markb873 · #2 01-03-2007, 10:47 PM

Being off by a tooth wont set that code. I think it's probably an advance/retard issue with the exhaust cam. Based on how the engine runs. Either the VCT flange wasn't set at 12 O'clock(if the exhaust spocket was loosened) Or the cams aren't aligned with the crank or with each other. I highly doubt the sensor is bad.

-Mark

farmer_andy · #3 01-04-2007, 12:35 PM

Thanks for the prompt reply Mark, I didn't loosen the flange. I set the cams up with the spacer bar in the end so they couldn't move (valves facing away from each other on the #1 cylinder) Set the crankshaft at TDC, (the key in the crank was at 12:00 position. removed the #1 spark plug and put the screwdriver in the hole, turned the crank until the piston was TDC. The key on the crank lined up at 12:00 at that time. Put the belt on, adjusted it as specified. Pulled the cam lock tool from the cams. Put it all together and it started and ran fine. Just got that pesky code coming back. If the cams wern't aligned with each other or the crank, would it still run OK? Thanks for the info.
Andy....

Markb873 · #4 01-04-2007, 11:50 PM

Maybe try the sensor. Its only about $15. One time when I set up my timing wrong, I was off maybe, 3-4 teeth and it never threw a code. The car ran OK but I lost gas mialage. When I got a p0340 it was because the exhaust cam was not advancing. and I had a bad VCT solinoid (which later threw a VCT code but not right away.) If that was the case the engine would run like crap. I used a timing peg when I changed mine so I'm not sure if it would trip when the timing goes a notch or two in the other direction, as the peg stops the crank and timing is set with pressure against the peg. Check your timing again. It took me twice to get it right.

I checked my OBD II manual, and it says p0340 should be either a sensor or wiring problem. It may have just been murphy's law and the sensor broke when you changed your belt. If that's the only code coming up after a few days i'd start there as there cheap.

-Mark

bowtieboy12 · #5 01-05-2007, 09:05 AM

P0340 is camshaft position sensor circuit "MALFUNCTION" meaning probably the sensor. Try this http://www.trixology.org/Repair/05/200o8c05/cip0340.pdf step by step process what to check in order.

farmer_andy · #6 01-05-2007, 11:14 AM

Thanks again Mark for the info. and bowtieboy12 for the test procedure on the sensor. I'm just going to change out the sensor this weekend since it is inexpensive. Hope that fixes it. I'll erase the code after the change and hopefully it dosen't come back. It is my daughters car and she did mention the fuel milage has been not up to par since the light has been on. I didn't replace the shields so checking the timing again shouldn't be hard. Thanks for the info.
Andy....

Paul78zephyr · #7 01-22-2007, 03:18 PM

Did you ever find out what caused the P0340 code? Im doing my belt soon.

Paul

farmer_andy · #8 02-08-2007, 02:43 PM

Update: Put a new cam sensor in and the car ran great for about a week. Going to work one day and the check engine light comes back on. Checked code and P0340 back!! When the light comes on the car runs lke crap. Stumped again!! I read in a previous thread of someone having problems with the VCT and having to replace it. Does it seem likely that I could have the same problem? Thanks for any information.
Andy....

Markb873 · #9 02-08-2007, 10:50 PM

My VCT went at 90,000. The symptoms sound the same to me as when mine went. When the car acts up unplug the cam sensor if it runs normal, the cam sensor is working correctly and the VCT is probably bad. You can check the VCT by running the engine at about 2500 and unplugging the VCT, the engine should change back the valve timing if it doesn't the VCT is most likely stuck. Get ready though it's a $300 part. Also the passages in the VCT can get clogged with oil, metal shavings, etc.

-Mark

farmer_andy · #10 02-14-2007, 01:16 PM

Thanks for the information. I'll try those procedures this weekend. Funny thing is, when I reset the codes, the car runs great for about a week, then the code comes back on. When the check engine light is on the car runs bad with a loss of power and bucking. Even at highway speeds, at times you can feel the engine buck. This goes away when I reset the code, until next time.
Still confused. Is the VCT something that would go away with the computer reset?
Andy....

POST REPLY TO THIS THREAD