CAS Questions...intermittent HORRIBLE idle.

[HeavyDuty]

Man, this forum is busy the last few days with all sorts of problems.

I performed this search http://www.nissaninfiniticlub....ber=5

with respect to CAS questions. Finding the "power" post by Tech (a great read).

Unless I missed something in my search, I still have a question;

Twice in the last six months I have had a warm start that results in what feels like the CAS is reading 180 degrees out. When this happened the first time, I was not driving the car & the driver shut it off, waited a minute, and tried it again, it was fine.

It did it to me today, I tried two seperate shut offs, and it did not clear up.

I shut off again and did a fairly thorough roadside inspection only to find a broken harness loom on the driver's side firewall. When I retried it, it was fine again.

It literally felt like not one cylinder was getting fire at the right time, had to be gingerly driven or it would stall. Horrible vibration through the whole car, but I could not pull over with the kids in the car, no shoulder, 6pm traffic.

MAF connector in good shape, CAS connector in good shape, new pump, good FPC, new fuel filter, clean TB, clean MAF, old spark plugs, but doubtfull it would come & go like this.

What happens when good CAS's go bad? Also, possible coil failure imminent? Igniter?

I should just start from the beginning tomorrow, but wanted a heads up from anyone that may have experienced the same behavior.

TIA

[Q45tech]

The Cas has TWO systems in one housing both have a wider pulse to tell ecu where the CAS [thus cam and crank] is in respect to x degrees before TDC of #1 and narrow pulses every degree [359] with [4] medium width pulses at 90 degree increments for the fine slotted optical wheel and medium pulses every 90 degrees for the variable reluctance [magnetic wheel] [one wide, 3 medium].

When the 1 degree pulses disappear the 90 degree are enough to bring the engine to a controlled stop or limp mode with a limit of say 2,000 rpm.

[squeefoo]

Have you found anything out yet?

[elwesso]

Dennis, I dont know if youve mentiond this before, but can the CAS wear like the TPS can at higher mileage and at only cruise??

Maybe the CAS on HD's Q gets sort of a funky connection sometime???

HD, when ti acts goofy do you get a CEL?

[HeavyDuty]

No CEL, just an unbelieveably bad idle.

I fiddled with the CAS connector while it was running and no change. Unlike when I whacked the CAs with my fist while changing oil.

It hasn't done it since, strange.

I saw a couple of posts where some had to replace them CAS, does anyone have experience on what they do when they start to go bad?

[Q45tech]

Before you spend $500+ good idea to use a Consult to monitor rpms under acceleration as the CAS is where the rpm signals come from.If the car accelerates from 4,000-6900 rpm obviously the CAS is sending nice clean correct signals.

The J30 is a special case as the method of joining the CAS to the cam is quite different: male spline on CAS fits in femal spline socket on cam. High mileage can wear the female socket allowing the timing to move around up to 20 degrees [shows up with timing light]. Requires a cam and CAS change to achieve as new.

The Q uses a different non wearing joining method.

Be sure you check both CAS outputs for corrosion: the on CAS socket and the hidden cable under the front top plastic decorative cover......where the connector is]!