New DTC popped up today

[RAF7789]

first off, my PO400 has been tripped for a week and i haven't had the time to deal with it again. (i already cleaned it out in june) It began studdering at low rpms when it was warmed up the idle also got rough. But today, after a 15 minute drive, the idle would occasionally lope very low. This bothered me very much because it reminded me the end of my first optispark. So i scanned it and it came out with PO336 Crankshaft Position (CKP) sensor circuit performance. I replaced the entire optispark unit, so its only a 4 month old optical sensor. Any ideas?

[Injuneer]

The crankshaft position sensor is not part of the Opti. Is a reluctor gear on the nose of the crank, right under the timing cover, and a magnetic pickup that pushes into a hole on the timing cover. The only purpose of the CKP sensor is to detect misfires. It should have no effect on the performance of the engine. But, its signal is compared to the pulse patterns from the Opti, so if you have a problem with the Opti sensor, which would cause the engine to run rough, it may show up as the CKP code.

I would check the CKP sensor first, but it doesn't sound good. Have you checked the harness connector for the Opti to make sure the pins aren't corroded or damaged?

[RAF7789]

it is a brand new opti harness connector and opti. Although......i bought the Summit Racing Brand optispark, a bad call on my part The EGR is sitting in cleaner right now. Do you think that may have caused the studdering/hesitation? How would i check the CKP sensor?
1. remove fans, radiator cover, water pump, c/s pulley, opti,
2. lower the oil pan
3. remove the timing cover
4. ?
Thank you for the tip!

[RAF7789]

ok the CKP sensor had oil in it because of the slow oil leak i have. So i wiped it all out and plugged it back in. (already checked the opti harness). the car ran fine for about 15 minutes and then it wouldn't start back up. my questions:

Is there any other probable cause of the no-start condition?
Is there any way to check if it is a faulty CKP sensor?

Thanks!

[Injuneer]

Is it possible that oil leak is also putting oil into the Opti?

[BrdWAtti2d]

Is it possible that oil leak is also putting oil into the Opti?

That's what caused mine to go south. Leaky front seals.

[RAF7789]

good point.... so if i just pop off the vacuum lines at the bottom of the opti, would that give me a good idea of whats going on?

[Injuneer]

You could look for signs of oil in the Opti vacuum hose or the nipple on the Opti. Might not show up there. Problem would be the oil coating the optical wheel and light/receptor.

[RAF7789]

i thought the Optispark unit was pretty sealed... how could oil possibly get in? the only way i could think of is either coming in through any of the skpark wires/ coil wire...possible? yes, but not probable though.

[Injuneer]

The back of the Opti fits into a hole in the timing cover. Its normal to have oil in the timing cover area. There is a seal that (hopefully) keeps the oil out of the Opti. It wouldn't be coming through the case and wire connection seals.... that's where the water/coolant gets in, particularly through the tower that the PCM-to-Opti harness connector attaches to.