P1345

So I'm driving the Miata home from work tonight, and it starts occasionally missing/bucking at a steady 80mph cruise. I back off a bit and then give it full throttle to see what's going on, it misses more severely, and the check engine light comes on.

I pull over, kill the engine, and restart it. Light still on. Pop the hood, check the plugs wires, quick scan under the hood (this was on the side of PGBT right at the height of rush hour), can't see anything obviously amiss.

Fire it back up, and proceed home at a more sedate pace. The car makes it home without further issues, but I've got a P1345 "no SGC signal input from camshaft position sensor while engine rotates" code.

I haven't run through the inspection procedure yet - hopefully tomorrow night. Unfortunately I've got a presentation to give to the VP tomorrow, so the car will have to wait. Thankfully, the CRV was ready to pick up tonight, so I'm back to two out of three cars running. :?

I've put 340 miles on the engine since I got it back form the shop. Could this be related to the reinstallation of the engine, or is this just horrendously coincidental? Has anyone else had this issue?

You gave advice on this problem last year!

on this thread: http://forums.dfwmiata.com/printthread.php?t=2654&pp=30

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altiain 05-02-2005 10:16 PM

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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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Uhh... yeah.

I know what the diagnostic procedure is. I'm trying to determine if this could be related to my recent engine rebuild, or if it's just another example of the exquisitely bad timing that my life is occasionally famous for.

Well... maybe you should check the plugs on the wiring harness... and check the harness too to make sure it isn't pinched somewhere. ;)

Altiain, I had that problem this summer. It is a relatively cheap part, and obviously is easily replaced. I have read on M.net that you can pull it out and wipe the surface clean. Apparently it is a magnet and can be messed up by being dirty. Doing that will allow you to check the wiring harness. That is what I would check. The wires though dont really have a place to get messed up from the engine install. They run straight into a large piece of the wiring harness that goes back through the intake manifold area.

Did you check the sensor on the valve cover?

Weren't you going to powder coat the valve cover??

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Originally Posted by POS Racing

Did you check the sensor on the valve cover?

Weren't you going to powder coat the valve cover??

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Didn't happen. Powdercoating the valve cover and rebuilding the transmission were overruled by my "financial advisor". :wink:

I'm going to pull the sensor, clean it (like majik suggested), and run through the shop manual diagnostic procedure tonight. Sounds like it probably wasn't caused by the rebuild.

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Originally Posted by altiain

Sounds like it probably wasn't caused by the rebuild.

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Yea I think it just need attention! ;)

Well Sparky ya figure out anything??

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Originally Posted by POS Racing

Well Sparky ya figure out anything??

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Ran through the diagnostic procedure tonight & harness is good. Cleaned and adjusted the sensor. Still have a check engine light. I'll order a new one from Mazdacomp tomorrow. Sigh...

Give it a bit, the light takes a day or two to go off. With my situation it would go off and work for a few days before repeating.

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Originally Posted by Majik

Give it a bit, the light takes a day or two to go off. With my situation it would go off and work for a few days before repeating.

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In which case it doesn't sound like it was fixed at all... :wink:

Correct me if I'm wrong, but if I've solved the problem (and disconnected the battery during the process), the CEL ought to go away. Continuation of the CEL means continuation of the problem.

Im sorry I wasnt being specific. The problem was intermittent. And the light would go off after a few cycles. Then the problem would happen again when the car got extremely hot. If you disconnected the battery and it came on again yeah obviously the part is bad. Does the car even run? My car was undriveable when it got too hot and the issue surfaced.

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Originally Posted by Majik

Im sorry I wasnt being specific. The problem was intermittent. And the light would go off after a few cycles. Then the problem would happen again when the car got extremely hot. If you disconnected the battery and it came on again yeah obviously the part is bad. Does the car even run? My car was undriveable when it got too hot and the issue surfaced.

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Yeah, it ran okay last night when I test-drove it, but the light came on again when I started it up and never went off.

The first incident occurred while I was running at a steady 80+mph cruise on the tollway. After I pulled off and checked under the hood, I pulled back onto the road and drove the rest of the way home at 60-65mph, and had no more bucking/missing incidents.

I'm going to order a new sensor from Mazdacomp today. Hopefully I'll have it running in time to heat cycle the race tires and put 500 miles on the motor before next weekend.

Good luck Iain, sorry you are having so much bad luck here lately.

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Originally Posted by Billy Blaze

Good luck Iain, sorry you are having so much bad luck here lately.

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Thanks, Billy. It'll all work itself out somehow. It always does.

Hey for those who will search this issue in the future, what is the Part Number of the Sensor??

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Originally Posted by POS Racing

Hey for those who will search this issue in the future, what is the Part Number of the Sensor??

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Dunno. I was going to call Mazdacomp and ask for a "crank angle sensor for a '99 Miata". When the part shows up, I'll update this thread with the part number. :wink:

Crank Angle Sensor BP4W–18–230 Illust. No. 2

But isn't this the sensor mounted down by the Crankshaft? Majik a liitle help please! ;)

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Originally Posted by POS Racing

But isn't this the sensor mounted down by the Crankshaft?

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:scratch:

The sensor mounted down by the crankshaft is the crank angle sensor.