Engine cut-out: Please help!

My usually reliable Miata is letting me down! Can any of you guys help in tracking down the problem?
I have been on the freeway twice today, doing around 70, when the engine starts to faulter and loose power. It seems to start missing on just 1 cylinder and then it spreads to others and progresively gets worse. I have to pull over and the engine will not run after 30seconds of doing this. It then will turn over, but not fire and re-start. After 15 mins it will fire up as normal and acts perfectly. The engine warning light comes on, but oil pressure was good and it did not overheat. Neither was anything leaking out the bottom.
I'm taking it into the Mazda dealer tomorrow, so I can check out the engine fault code, but have any of you guys had this before? Any suggestions on what I can try investigating would be greatly appreciated!

Many thanks

Luke

What year Miata? Sounds suspiciously like a coil to me. If you're around Plano, I can read the code for you this evening - or your friendly neighborhood Autozone can do likewise.

If it is a coil (and you're past the emissions warranty period), you'll want to avoid driving it as coil failure tends to lead rapidly to cat failure.

What year is your car? Autozone will read the code if it is newer then 1996 OBDII. If it is older then you can find the Diagnostic port in the engine bay and use a paperclip that has been unfolded to connect the "ten" and "Gnd" (they will be labled) turn the car on and it will flash the codes it has to you. Both will be cheaper then the dealership.

Chris

The car is a 2001 model, with the 'coil on plug' type of arrangement - seems to have 2 coils each feeding 2 plugs. I'll try Autozone if they can read the code for free!

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Originally Posted by tailchaser

What year Miata? Sounds suspiciously like a coil to me. If you're around Plano, I can read the code for you this evening - or your friendly neighborhood Autozone can do likewise.

If it is a coil (and you're past the emissions warranty period), you'll want to avoid driving it as coil failure tends to lead rapidly to cat failure.

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Thanks for offer of the code reading, but I'm right the other side of fort worth unfortunately so I'll try Autozone tomorrow. Mine's a 2001 model.

The local Autozone read the code as P1345 - 'CMP sensor circuit malfunction' - any ideas?

Camshaft/Crankshaft position sensor malfunction...

Not sure on the 2001 but I think that's down by the crank pulley on the 03... Did you run through any brush, hit any hard objects, or have any work done under the hood? If the sensor isn't whacked out of position then it's probably needing to be replaced.

I'd not drive it too much... something like that will whack out the timing pretty badly.

RJ

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Originally Posted by channelmaniac

I'd not drive it too much... something like that will whack out the timing pretty badly.

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Yep... if it is still under warranty, you should call the dealer before driving it again. They may want to tow it in to prevent any chance of causing further damage.

Edit: On the other hand, the dealer may not care if more damage occurs... I believe Mazda pays them for the warranty work, so the more that needs to be done, the more money that ends up in there pocket. :rolleyes:

I think you have two sensors. the one by the crank pulley and the one in the front of the valve cover. Not sure if 2001's had the one in the valve cover. Try Miata.net, bigger user base, but search first or they will jump your ass.

Chris

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Originally Posted by Kags1969

I think you have two sensors. the one by the crank pulley and the one in the front of the valve cover. Not sure if 2001's had the one in the valve cover. Try Miata.net, bigger user base, but search first or they will jump your ass.

Chris

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Yes, I do have 2 sensors - 1 down near the pulley and the cam sensor on the valve cover. Neither look damaged, and I removed / cleaned the cam sensor (which was clean). Miata.net was useful - I think from their postings where similar things happened and the fault code that it's probably the cam sensor so I'll order one of those and see if that cures it!

Many thanks for your help!

Luke

I don't know how mechanically inclined you are, but here's the diagnostic procedure from the '99 shop manual (ought to be the same for the '01, iirc) for a P1345 code:

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Originally Posted by altiain

I don't know how mechanically inclined you are, but here's the diagnostic procedure from the '99 shop manual (ought to be the same for the '01, iirc) for a P1345 code:

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Hey - thanks Iain, I'll get my multi-meter out tonight and check these things out!

So what ended up being the problem??

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Originally Posted by POS Racing

So what ended up being the problem??

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No kidding... what happened already?

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Originally Posted by POS Racing

So what ended up being the problem??

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OK - I thought I'd leave it a few days after my repair to see if it happened again (as the fault was not very repeatable). I even re-traced my journey to DFW airport where it happened twice before - and thankfully no problem at all! After following the suggestions from DFW miata, reading some chat on miata.net and tracing what the fault code meant I was pretty certain it was the Camshaft angle sensor - sitting right on the top of the valve cover on my engine. I didn't want to pay the local Mazda dealer more than I needed to, so I bit the bullet and just went ahead and got a new one for $100. It was the easiest part ever to change (1 bolt, 1 electrical connector, right out in the open) and thankfully it did the trick. It might just be in my mind but I think it may start quicker, idle smoother and rev happier at high rpm now too. I hope there's something very high-tech inside that little black plastic tube for 100bucks! Anyway, that's this problem sorted out - many thanks to all who helped from DFW miata - I hope to meet up with some of you soon.

Cheers

Luke