Hard start, rough idle...

Because this week hasn't been fun enough already...

Went to take the car out today and she didn't want to start. On the third try, she started and ran fine, except the "Check Engine Light" came on. It has done this once before. So I did my errands and the car started right up at each stop. The last time it did this, it started fine after the first hard time and the C.E.L. went off after a few stops/starts. So when I got home this time, the light was still on. So I killed the engine and waited a minute and hit the starter. It fired right up, light still on. Killed it and waited a few more minutes. Started right up and the C.E.L. went off!! Yeah!! Except that the car would barely idle?!?! It would go to 900~1,000 rpm for a few seconds then drop to around 400, start to stall and then jump back to 900. It did this over and over and over... I stopped the motor and let her cool off before trying again. Same result. :(

Any ideas?

Run by an AutoZone and have them check the code for you. Get the actual code (not just the often wrong diagnosis that the Autozone idiot gives you), and post it here.

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Originally Posted by Titus

Run by an AutoZone and have them check the code for you. Get the actual code (not just the often wrong diagnosis that the Autozone idiot gives you), and post it here.

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Well, since the light went off, that was going to be a trick.

However... I just went out to try again and it took three tries to start. At the moment it is idling just fine, but the CEL is back on. :confused: I'll run up to Autozone and see what they say and post it here.

Ok, went to Autozone and almost didn't make it back (we've moved from rough idle to stalling :( )
Anyway, the tech wasn't keen on sharing the code, but I got a look at the readout and it said P0340, which they say is the camshaft position sensor. Which means nothing to me... ;)

Oh yeah, woo-Hoo! Post 100... ::Blah::

What year car?

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Originally Posted by channelmaniac

What year car?

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D'oh!
2001 LS She's green, if that makes a difference ;)

Well, P0340 is indeed the code for Camshaft Position Sensor Circuit Malfunction. Here is a thread from Miata.net where someone was having similar problems with the same code. They replaced the sensor and all was good. Call Trussville Mazda now and they may be able to get one in the mail today.

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Originally Posted by Monkey of Death

Oh yeah, woo-Hoo! Post 100... ::Blah::

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Congrats! ;)

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Originally Posted by Titus

Well, P0340 is indeed the code for Camshaft Position Sensor Circuit Malfunction. Here is a thread from Miata.net where someone was having similar problems with the same code. They replaced the sensor and all was good. Call Trussville Mazda now and they may be able to get one in the mail today.

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Thanks Titus!
I checked for more info on swapping the sensors out and am a bit hazy on it. Just to make sure I'm reading things correctly, this is what I'm supposed to swap out, right? It doesn't really seem right since it is a bit too easy to get to. What's the catch?!? ;)

http://www.johnlanning.com/cpsensor.jpg

Sorry... I'm out of answers. I have a '92 and it doesn't have anything mounted there. :confused:

Call Gary on his cell & see if he has one in his boneyard.

RJ

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Originally Posted by Monkey of Death

Thanks Titus!
I checked for more info on swapping the sensors out and am a bit hazy on it. Just to make sure I'm reading things correctly, this is what I'm supposed to swap out, right? It doesn't really seem right since it is a bit too easy to get to. What's the catch?!? ;)

http://www.johnlanning.com/cpsensor.jpg

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Thought that deal had something to do with the VVT. But I could be wrong......

OK so I decided to get all scientific and see what happens when ya unplug the deal you have pictured.

On the wife's '02 it kicks a P0010 code as soon as ya unplug it (I have my own code reader) Which shows as a "A" Camshaft Position - Actuator Circuit (Bank 1). Strange it doesn't throw the same code as yours??? Anyone know why??

BTW a P0340 = Camshaft Position Sensor Circuit Malfunction

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Originally Posted by POS Racing

On the wife's '02 it kicks a P0010 code as soon as ya unplug it (I have my own code reader) Which shows as a "A" Camshaft Position - Actuator Circuit (Bank 1). Strange it doesn't throw the same code as yours??? Anyone know why??

BTW a P0340 = Camshaft Position Sensor Circuit Malfunction

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Could it be that one code (P0340) means the sensor has a short or other problem and the other code (P0010) means that it is disconnected or not reading at all? Just asking/guessing. I'm new to the whole 'engine code' thing :confused:

I may try calling or emailing Gary on Friday. A good used part would be a good way to verify that that was indeed the issue before dropping real $$ on it. Heck, it may also be a permanent fix. :D

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Originally Posted by Majik

That is not the cam sensor. It is on the front of the engine bolted to the valve cover.

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Nope not on the '02.. :confused: It is on valve cover of my '99.

http://forum.miata.net/vb/showthread...=01+cam+sensor

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Originally Posted by Monkey of Death

Could it be that one code (P0340) means the sensor has a short or other problem and the other code (P0010) means that it is disconnected or not reading at all? Just asking/guessing. I'm new to the whole 'engine code' thing :confused:

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Could be, I also noticed the car idled just fine with the sensor unplugged.

Ok, I found this thread with a link to this photo:

http://www.y8spec.com/images/whatsensor.jpg

They identify that as the Camshaft Position Sensor. Are they correct and this is what I need to replace? Still appears way too easy to get to ;)

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Originally Posted by Monkey of Death

They identify that as the Camshaft Position Sensor. Are they correct and this is what I need to replace? Still appears way too easy to get to ;)

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I could always unplug that and see what code the '02 kicks up. ;)

::Whisp:: Just don't tell Vivid!

Do it!