Ok, so i finally got time today to check out what is wrong with the Z i just purchased. The prev owner said its not getting a spark. He said he checked the ecu and its fine, the ptu as well and its ok. he said he just hadnt checked the CAS. So thats what im checking right now.

I pulled it out and have the car to the 'on' position. as i turn it, the only sound i hear and feel is the solenoid by the battery click. From my last Z, i remember that to be for the AIV system which i had disengaged in my Z before. Is this suppose to be clicking? thats all it does, spinning it fast or very slow. but sometime while spinning it click i hear a random click somewhere else.

So im assuming the CAS is bad and that one is suppose to click but im also suppose to hear the injectors as well to right? if someone could help, it would be much appreciated. thanks.


Modified by redincali at 8:25 PM 1/12/2010

on well im done for the night. i had my friend helping me with this. he was using his voltage meter to check for power off the CAS plug with the car in the 'on' position. he tested the top wire first (not noticing his setting was on mwA) and the solenoid clicked over while the injector closest to the driver was buzzing, either the injector or the coil pack. i didn't remove the balance tube to remove it.

i have never used the mwA setting before, does it feed power? and if so, should only that one be buzzing like that along with the solenoid clicking? because that was the same resule i was getting if i spun the CAS manually.and now that im thinking of it, it must have been the coil buzzing because with the CAS connected and me trying to start the car, my friend tested the coil for power (after i told him he had it on the wrong setting, not DC) and that coil got power as i tried to start the car.

when i turn the key it sound as if its about to start, but it just needs that spark. ill look more into it tomorrow, but for tonight im done. now its research time and hoping i can find some good help.

Have you run ECU diagnostics? That might tell you where the open circuit is.

http://www.ttzd.com/tech/diagnostictech.html

The second thing I would do if pull the CAS plug and see if it's 100% corrosion free. That is often the issue of it not working. Fouled connector or bent contacts will cause it to barely or not work at all.

If you turn the CAS you should hear each injector click,providing it's quiet where you are doing it. What I would do is pull a coil pack, plug it back in, insert a spark plug, ground it and then turn the CAS (with ignition to the on position). You should see the spark plug fire.

If it doesn't I'd be looking at the wiring and PTU first before buying a new CAS. Sometimes the wiring that runs in front of the engine comes loose and is damaged by the fan causing no power to go from the PTU to the CAS etc.The CAS doesn't often fail. Is your PTU the silver ribbed type of the flat black one? The silver ones are prone to failure and on the Nissan recall list so you should be able to get one for free if it is.

No i haven't ran a diagnostics yet, but i planned on doing it today. i used to do it on my last Z, she was a code 55, miss that car. but i do have the newer style ptu, i remember checking my last car for the old style. i did alot of researching last night and im thinkin it might be the ptu as well.

i read that theres a black loop on the ptu for timing, and that if the ptu is out then the timing light wont work correctly on that loop. is that right? i planned on checking that today. i also rememver seeing a Z in the pick a part a few month ago, im going down there today, maybe i can snag the ptu if its not gone. my other question is, is the CAS suppose to spin very freely without any tension on it, by hand?

it is quiet enough for me to hear as i turn it but only one injector or coil clicks/buzzez if i spin the CAS at a steady speed. if i do it slow, it just clicks over. but not only the coil/injector, but a solenoid by the battery which i remember was part of the AIV system. should that be activating?

the plug on the cas looks clean, actually almost new. it is actually spliced on there with wire nuts but the connections are solid. ill replace them with butt connectors when i buy more. i haven't check the ptu for corrosion yet either. ill post later when i find more out.

btw, what is the order on the engine for firing when looking at it from the front? i tried the front 4 coils for a spark (ones not under bal tube) and so far none. i went and bought the kit, it also works for recessed plugs like ours. the guy i got the car from gave me 6 more coil packs as well. he said he had them tested 2 times and the 2nd time they were working better than the first. but he said the coils already in there were tested as well and they are good.

ok well, its pretty much narrowed down to the CAS now. I just ran a diagnostics on the ecu and that was the only code coming up. i watched it flash 1 long pause and 1 quick pause back and forth for ove 10 times so its an 11 code for sure. i just hope another problems isnt there, just without showing the code #. i knew i should have done this yesterday heh, but it gave me something to do.

i dunno if i mentioned in my other post, but i got 3.7k for my last Z. well, its on its way. check was processed yesterday but sent out today. i only paid 2.3k for it, but put alot of work and time into it. more than 1.5k of parts. so i came out alright i guess. this Z cost 1k so theres still 2.7 to play with

Yup, code 11 is CAS circuit. If you have the new style CAS, it's because someone installed it. As you mention it's spliced in, and the new style connector is pretty weather-proof, so it likely won't corrode but many others can and will. I would check that is was wired correctly from the start, and that all connections are good. Butt splices are crap on something like that. It should be soldered and heat shrunk to maintain the integrity of the connection. Highly important on electronics.The CAS should spin pretty easily by hand. When rotated slowly you should hear each injector fire (and each coil pack if you do the spark plug test).

Firing order is 1-2-3-4-5-6

That loop on the PTU wiring is for timing with an inductive timing light. If the PTU fails, it won't run so it doesn't really matter. The new style PTU requires the sub harness to directly plug it in, unless you rewire it. I did a wiring diagram to take the confusion out of it


Modified by Zwicked at 6:55 AM 1/14/2010

thanks Zwicked. Ill go out today and redo the connection on it to make sure its the CAS and not its wires. It looks like an old style CAS, not a newer one. Thanks for the diagram as well, ill make sure those are all in order too. im still not sure which order it fire tho. i understand the 123456 but im not sure where each is located. is 1 the closest to to the front on the left or right? or is it the only one thats clicking for me, which is on the back under balance tube on driver side? thank again

1 is the front passenger side, 2 is front driver side and so forth, alternating side to side. Turning the CAS slowly with the ign on should give you 6 clicks, one for each injector, every revolution of the CAS shaft.

*** Make sure your battery is fully charged

uh oh, more of a problem than i thought. well i guess i should have looked yesterday at the plug. it wasnt plugged into the cas.... i just ran a diag. again and im getting a code 55. so i just unplugged the battery to reset it so i can try again, ill post the results.

update: well im still getting a 55 code when everything isn't 'ok'.
Modified by redincali at 2:55 PM 1/14/2010

Did you pull a spark plug and test it by turning the CAS as I mentioned? This will confirm if it's working or not. I would not rule out a dead PTU. Have you tested it as per the manual?

ok. well the fuel pump fuse was pulled the last time i had tested the cas. didn't know it would actually mess it up. so with it plugged in, i can hear each injector spray and i tested all 6 coils, they have spark. one time it actually kicked a lil and the fan turned as i spun the cas. would that mean its the ptu, timing, or something else? thanks for the help so far by the way. very very much appreciated

If you have spark and fuel the only other elements needed are air and timing. Is you battery fully charged? Question: Was there some work done by the previous owner and then it wouldn't start...such as plenum pull or timing belt?

im not sure what they did exactly. he went into the navy so i had to get it by last sunday, thats why i got it for so cheap. he said he changed the motor but didn't say if he did any actual work on its internals. i know someone messed with the timing before, but not sure if it was him or from where he got the motor. i think they changed the cam gears because the metal backside of the timing cover is bent like it was pried on. my next thought was to tear it down and get those covers off tomorrow. i already have the radiator and ran out of the way. just need the belts and intake piping out of the way.

I would:

1. do a compression test, and if that's ok2. take off the timing belt covers and see if it's timed right. There are lines on the belt. One of each of the lines need to line up with the dot on each cam and crank sprocket to be timed right.3. pressurize the intake ( max 5 psi) and see if there are any massive vacuum leaks

I'd bet it's something like that. If there is air, spark and fuel and the timing is right, it has to run, providing there is compression in each cylinder.

ok thanks. ill definately check the timing tomorrow. i just did it on my last Z, rebuilt the pulleys with expensive bearings. too bad i couldn't keep them. ill let u know what i find out. if i can, make a small video of it

well i didn't have much time to check out the Z today but i did get the front out and the timing covers off. after turning it by hand, they all line up but one so tomorrow ill get the timing set and let u know the results.

If one line is off, it can keep it from starting. Hopefully it wasn't off enough with there was valve/piston interference. All that matters is each line lines up exactly with the dimple on each cam/crank gear. The dimples on the backing plates don't matter. I'd probably get it back to where they mostly line up and take the belt off and start over as well as check the idler and tensioners to make sure the bearings are ok. The tensioner will have to be removed so it can be retracted and the 10mm stopper bolt put back in. If you haven't done this before. Compress it slowly or it will break. I use a C clamp and just take your time.

I would still do a compression test.

ya i have changed it before. i got this one all apart today and set the timing. it was 3 off and 1 was 1 off. took the cas apart and cleaned it, cleaned all the plug contacts and pushed ones back into clip that were coming out. did all that stuff and got her goin. sounds great.

im going to solder and heatshrink the cut wires. still going to do a compression test and change all the spark plugs. the starter sounds strong, starts quick. all the belts are new, theres a new water pump, alt, and fan. radiator is new and a/c works but heater core is out, so thats next. thanks for all the help. much appreciated.

I saw in your post that you said that the Fan turned on while you were turning the CAS.

Mine did that today too. It rand for about 3 or 4 seconds and then turned off, multiple times as I was turning the CAS.

Is this normal?

Thank You Zwicked for the PTU wiring Diagram im gonna put that picture in my post that I had asked if any one had one an no one answered... THNX

Great, glad to hear you got to the root cause of the problem. It almost always boils down to fuel, spark, or timing.

You are welcome, glad it helped you out.

I saw in your post that you said that the Fan turned on while you were turning the CAS.Mine did that today too. It rand for about 3 or 4 seconds and then turned off, multiple times as I was turning the CAS.

Is this normal?

im not sure if thats normal but i dont see why not. if there is fuel, spark and compression, it should try to turn over when your turning it by had. im assuming because the CAS makes the coil spark and if theres fuel in there... well, its goin to ignite i think one of my main problems was the ptu connections. because sometimes the cas was working and sometimes not. but we noticed when it was running again, i followed the wires and got to a clip on the PTU that would kill the car if i wiggled it.

check the ptu connections for a green layer and use a pick tool or small screwdriver to bend the clips back tighter in the female side plugs. i dont think all were making a good solid connection before.

if your engine is turning over and your fan is turning, check all for spark and listen for the injectors. you can hear them spray as u turn the CAS, as well as hear each coil click