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Please Help, Cas Problem.


calais25t
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Okay I recently finished a build up of my car and have finally come to the turn key stage.

When I crank the engine I get all sorts of farts and blurps-Backfires etc but it wont run.

I had the crank/cam angle sensor off and I believe this is the problem as I have fuel and spark.

Now the problem is my CAS is not keyed so I have no idea where it should be?

Whats the easiest way to get it to the correct point before installation?

Do I just need to turn it a tooth and try again, and again etc.

Engine is an rb25det (I believe series 2) with standard internals.

Oh and when I pull the cas out and turn it the injectors pulse so Im sure its fine.

Im at my whits end I just want it running. I have searched and searched to no avail. :worship:

Thanks in advance.

Edited by calais25t
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Do I just need to turn it a tooth and try again, and again etc.
Basically, yes. Although it must be close.

However you should be able to see the surface where the half-moon key broke from in the end of the exhaust shaft. Just use visualisation to determine which is the correct alignment.

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Okay, so stupid question here,

Does one rotation of the CAS equal six injector pulses or does it need to rotate 6 times?

Is it possible Its injecting fuel into say cyl 3 and cyl 6 is the one that needs it? If you know what I mean..

What Im saying is could I be 3 or 4 rotations out or does it just work on one rotation. :)

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Okay, so stupid question here,

Does one rotation of the CAS equal six injector pulses or does it need to rotate 6 times?

Is it possible Its injecting fuel into say cyl 3 and cyl 6 is the one that needs it? If you know what I mean..

What Im saying is could I be 3 or 4 rotations out or does it just work on one rotation. :wave:

yes one rotation is one cycle of the camshaft. and one rotation of the cas is two rotations of the crank.

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remember because you've been cranking it but without spark it'll be full of fuel, take the plugs out n dry them, let it air abit then put em back in and re try...5 bucks its now floded with petty.

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There has to be an easy way to set the CAS. :(

i'm not sure if it will work out? but if you have access to a friends rb25det (R33) you could try it. set both the engines to TDC. on the other engine/car pop the lid on the cas so you can see the rotor plate. then pop your lid, match it up, then put it back on.

might be a bit of a stuff around but it sounds like your fed up with it. also what DEAD32 said, if your continually cranking your car and not sparking, you plugs with fowl up and worst case your sump starts filling with fuel. not nice.

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The teeth that mesh between the CAS and the cam are quite coarse. You have to turn the CAS shaft a fair bit to get it to align in the next set of teeth.

As I said previously, use a bit of visualisation to work out where the key in the CAS has to be to align with the "key" in the exhaust cam.

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Okay, Im sure the CAS is in the right position and the F&*%ER will not start...

Ive pulled the plugs and checked and they are sparking well.

Its getting fuel and the injectors are working.

My computor runs a map sensor so basically it cant be anything such as AFM or the TPS caus eit dosent have one.

Is there anything else here it could be its got me baffled?

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what ecu? what diagnostics does it have?

have you checked the basic sensors

- afm or map

- water temp

- cas

do you have spark? use a screwdriver tapped onto the engine block & try to crank it

do you have fuel? undo the fuel line and see if you have fuel coming out

do you have air? check the air inlet / afm or map sensor

lastly with whatever ecu you are check some of the basic sensors

even the std ecu has built in diagnostics to debug why it wont start

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yes, what ecu are you running? i just looked back to your first post and you say that you have fuel and spark, if the cas was faulty you would have these. how did you check for fuel and spark?

on some aftermarket ecu's you have to tell the ecu your firing order for it to work. also whats you battery voltage like? if its low your coils may not be charging properly giving you a weak spark.

Edited by QWK32
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yes, what ecu are you running? i just looked back to your first post and you say that you have fuel and spark, if the cas was faulty you would have these. how did you check for fuel and spark?

on some aftermarket ecu's you have to tell the ecu your firing order for it to work. also whats you battery voltage like? if its low your coils may not be charging properly giving you a weak spark.

Its an EMS stinger ECU.

It was perfectly tuned about 2 years ago when I took the car off the road, and as far as I know none of the settings should have changed.

To test spark I rotated the CAS and watched the spark plugs fire.

I can also hear the Injectors ticking and my fuel pressure gauge is reading 30psi of fuel pressure.

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On the last atempt I got a 6 inch flame out the throttle body.

that tells me that the cas isn't lined up properly. or you cams are out. have you checked that your timing marks on the cam pulleys all line up.

i know its probably unlikely, but is there anyway the ecu has been reset?

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that tells me that the cas isn't lined up properly. or you cams are out. have you checked that your timing marks on the cam pulleys all line up.

i know its probably unlikely, but is there anyway the ecu has been reset?

I havent touched the cams or the timing belt since it last ran.

The compuor still has the maps when I plug it into the laptop.

Im ready to set it on fire.....

Is the series 1 and series 2 CAS the same????

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Is the series 1 and series 2 CAS the same????

from what i understand the are, except the very late model 33's have one the same as a 34.

still running stock coilpacks?

what you could try is: (just to check everything)

unplug the injector harness from the main plug at the front so as not to inject fuel. pull the coilpacks out and place them where you can see them spark. manually rotate the cas and check that the firing order goes in the sequence of 1 5 3 6 2 4. you may not get that a first depending on your current cas position, it may start from 3, etc.

if thats all good, then set the engine to cyl 1 at TDC. with the cas held the right way up, rotate the cas till coil 1 fires, then turn it around a very tiny bit more. that'll be where the right cas tooth alignment to the cam is, then put that onto cam and set the cas bolts so they are about halfway in the slotted holes. this will be a good spot to start till it gets running and you can get a light on it.

then plug the injector harness back in. make sure they are plugged in the right way, and getting a signal. and your fuel lines are the right way around.

if thats all good the only things left are your MAP sensor, and ecu settings.

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from what i understand the are, except the very late model 33's have one the same as a 34.

still running stock coilpacks?

what you could try is: (just to check everything)

unplug the injector harness from the main plug at the front so as not to inject fuel. pull the coilpacks out and place them where you can see them spark. manually rotate the cas and check that the firing order goes in the sequence of 1 5 3 6 2 4. you may not get that a first depending on your current cas position, it may start from 3, etc.

if thats all good, then set the engine to cyl 1 at TDC. with the cas held the right way up, rotate the cas till coil 1 fires, then turn it around a very tiny bit more. that'll be where the right cas tooth alignment to the cam is, then put that onto cam and set the cas bolts so they are about halfway in the slotted holes. this will be a good spot to start till it gets running and you can get a light on it.

then plug the injector harness back in. make sure they are plugged in the right way, and getting a signal. and your fuel lines are the right way around.

if thats all good the only things left are your MAP sensor, and ecu settings.

I did try that but the problem is Im getting multiple sparks at the same time. Im sure the computor uses a wasted spark setup which makes it hard.

The other thing is it seems like the sparking is random depending on how fast I spin the CAS.

How do I know which stroke the number one piston is on ie intake or exhaust?

I tried unplugging the fuel line both into the rail and the return from the regulator and they both flowed a cup fuel in a couple of seconds but the pressure didnt seem massive, how much should there be?

Everytime I try and start it now, I pretty much get nothing followed by massive backfires I mean BIG.

One thing is I dont have the intake pipe on so its sucking straight into the throttle body although I cant see that making a difference.

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Here how I set my CAS up.

Removed #1 coilpack and put dummy spark plug in it to check spark.

Line TDC up on the crank with the marker (the red stripe on the pulley)

Remove CAS and turn the shaft with the ignition on, until the dummy spark plug fires. Make sure the plug is grounded.

Now without turning the CAS put it back in the motor. If it still doesnt start and backfires, then the #1 piston is 360 out.

Get the motor to TDC again on the crank pulley. Turn the engine over EXACTLY 360 degrees (1 turn). Refit CAS there and try again.

This will get the CAS close enough to start the engine and fine tune it from there.

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