WTF is my CAS doing???

[boiseDSM]

CAR: 90 tsi awd

PROBLEM: The car will only run with the CAS rotated almost all the way forward (advanced). I've tried timing it with a light but can't find any timing marks to line up. Having grounded the wire to the ECU, I swept the whole range on the CAS adjustment to see where the timing marks might show on the pulley. Found none. Since I can't time the car the correct way, I went with the redneck way of going my "feel." That means starting retarded and advancing the CAS to where the car feels best. In the center position close to where it should be, the car pulls massive timing and hardly moves. Moving it forward will feel better to a point. There seems to be no linearity of the adjustment. A small tap on the adjustment will show a day and night difference on how it drives.

I had posted before about this problem and it was suggested that the CAS needs to be "flipped" where it goes onto the cam. I checked and this was on the right way. The original CAS had been replaced because the wires had gotten brittle. Could I have an incorrect type of CAS on the car? The plug fits just like the original so I would figure that it would be fine.
I don't know if it is related or not but my O2 voltage never goes above 0.67v even when cycling at idle or cruise. At full boost it reads a constant 0.67v. I don't know if this issue is related or not but I do remember it cycling from 0.99 to 0 before. Seem strange.

OK, sorry to be so vague. I am trying to borrow a logger to help me out and steer me in the right direction to fix this annoying problem. Any input would be welcomed...


Thanks!

 

[oddrob]

Silly question, but have you checked the physical alignment of the timing belt?

 

[SBR Joe]

^^^^^ x2


Joe
Slowboy Racing

 

[steve]

I've tried timing it with a light but can't find any timing marks to line up. Having grounded the wire to the ECU, I swept the whole range on the CAS adjustment to see where the timing marks might show on the pulley. Found none.

As you already know this isn't correct.
First locate the timing mark on your crank pulley and turn the engine over my hand to line it up with the mark on the front cover. Pull the #1 spark plug and upper timing belt cover. Check that the crank pulley mark matches TDC on cylinder 1. Make sure that the timing marks on the cams also match up with teh dowel pins pointing up. If the cams are off then the CAS will never be correct. If the crank pulley is off then you won't be able to set the CAS.

If it all matches up so far, pull the CAS and make sure it's two timing marks line up.

From what you describe I don't expect you to get this far without finding your problem.
Also make sure your using a timing light that doesn't have a dial for timing advance on the back. That will throw things off.

Steve

 

[exile]

I've gotta bring back this post, I'm having the same problem.

I just got finished installing HKS cams and swapping over to a 1g CAS and I'm at the point in time where I'm trying to tune it. I have checked all of the timing marks and they look OK. I grounded out the timing with DSMLink and on the crank it's set perfectly on the "T" (0 degrees). On Link when I un-ground the timing and begin to adjust the CAS the numbers on DSMLink are CRAZY they just bounce constantly between 5-11degrees and there's absolutely no way I can get a straight number off of link. Just listening to the engine, if I turn the CAS all the way toward me (front of the car) it sounds great but as I turn it toward the windshield it just gets worst and worst to the point of dying.

When I ground timing and check it on link the number stays at 5.2 degrees and does not change.

 

[steve]

I grounded out the timing with DSMLink and on the crank it's set perfectly on the "T" (0 degrees). On Link when I un-ground the timing and begin to adjust the CAS the numbers on DSMLink are CRAZY they just bounce constantly between 5-11degrees and there's absolutely no way I can get a straight number off of link.

When I ground timing and check it on link the number stays at 5.2 degrees and does not change.

It's when you "ground" out the timing with DSMLink that your to set the timing to 5* BTDC not 0.

Once you "unground" it the timing is free to change and will bounce around 8-11* BTDC at normal idle.

 

[exile]

Thanks for the quick response.

So what exactly is my problem? Maybe I'm not understanding the objective here. I am suppose to match the timing on dsmlink with the actual timing at the crank? 0 degrees? I sorta can't because it bounces around so much.

I guess what you're saying is the GND Timing feature in DSMLink isn't exactly what I need to do? I did it that way because I cannot find the GNDing clip near the firewall.

 

[steve]

What your going with DSMLink is forcing the ECU into timing adjust mode where it locks the ignition timing to 5* BTDC so that you can synchronize the crank position sensor (CAS) with the ECU. On a 1G or a 2G with the ajdust timing connector you would ground this pin to put the ECU into that mode. With DSMLink you check the box to set the timing.

Where did you get the idea that it should be TDC (0*)? That's only for the timing marks for the belt.

Steve

 

[exile]

Oh, I got that idea because that's what you suggested for the original poster. You wanted to make sure his cams were set correctly before you continued with the diagnosis.

 

[steve]

Actually I was trying to verify several things. I wanted to make sure the timing belt was correct. That the CAS was installed correctly and that the harmonic dampener was good and hadn't separated throwing off the ignition timing marks. All of these things are indexed to TDC.

As you noticed, when you select the option in DSMLink to "ground" the timing connector it locks the ignition timing to 5* BTDC and if you look at the marks on the harmonic dampener and front cover they should be steady (and also 5* BTDC). Turning the CAS will let you set the CAS (The ECU engine timing reference) to match the engine.

So right now if you set your CAS to set the timing to TDC your ignition is 5* retarded.

I hope that helps.

 

[exile]

I think I may have the idea but something's not right here.

If the timing is set to 5degrees BTDC and I check it with the timing light it was showing it was exactly on the "T" mark on the crank pulley. You're saying it should be on the 5 degree mark (the first tick mark). Would that explain why the CAS only sounds good if it's turned all the way toward the front of the car? It's almost like if I could turn it just a little further, possibly taking the bolts out of it.. it would keep sounding better and better. Also, it sounds REALLY good when it's revved passed 1k, sounds perfect.

Also, how in gods name am I suppose to be able to tell where the CAS is set with DSMLink if it keeps flipping out between 8-15 degrees? Would it work correctly If I used the physical grounding method?

P.S.: Reading more into the dsmlink forums, if I am in GND Timing mode with Link, and I turn the CAS will that change the timing I see from my timing light at the crank pulley?

 

[steve]

If I am in GND Timing mode with Link, and I turn the CAS will that change the timing I see from my timing light at the crank pulley?

Yes, turn it until the timing mark lines up with the 5* BTDC mark.

Steve

 

[exile]

Steve, I want to thank you for your help. I really appreciate it.

I figured it out, well I got as close as I can. The stock is around 5.2 degrees according to DSMLink and my mark is just under the 5 probably like 4.5degrees. Turns out I had the CAS installed 180 backwards, I didn't see the little notch mark I was looking at the picture incorrectly and I was lining it up with something else. Once I flipped it, it ran REALLY well...

However.. I noticed something that intrigued me. Bringing it all the way forward did bring the timing mark on the crank pulley closer and closer to the 5 degree mark, but as far forward as I could get it, it only stopped at 4.5degrees. I noticed on the CAS itself the oblong holes that the bolts mount through (and if you're reading this guy, touche') were rounded out where the bolt would touch if it were pulled all the way forward. I'm thinking the guy that sold this to me knew about this problem and that's probably why he sold it. I'm assuming it's a slightly bad CAS that needs to be turned further than it should to get it to hit 5 degrees.

Just to recap, I didn't realize that when you turn the CAS it actually changes where the timing mark is on the crank pulley. I guess this was my timing tutorial. (Is that right Steve?)

Anyway, Thanks Steve for your help. Hopefully this helps some other people, and I'm sure I have a boat load of more CAS related issues that I'll have to replace this CAS to fix.

 

[Auto RS T]

Exile, I have been following this thread and just wanted to throw in my 2 cents.

Did you verify that the timing marks on the cam gears line up using a ruler while the crank is at TDC?

If the intake cam is retarded 1 tooth, the CAS/Ignition Timing Mark will act like what you have described- Only advancing near 5* while nearly maxing out the CAS range, when setting ignition timing. The car may still have good vacuum and runs well, but the cam may be off. Just something to check out...

 

[exile]

Auto RS T, thanks for your help.

I have verified a few times that the timing marks lines up correctly on the cam gears. The project of replacing my CAS was began by me installing my new 264/272 combo. I also have been reading about being 180 out, and I'm pretty sure I'm not because I've missed being TDC a few times and had to go through 2-3 times in a row to make sure it's set and they always land in the right spot every time.

I will take a picture of what I'm seeing, to confirm with you that I am lined up correctly. If you're saying that what I'm experiencing is a byproduct of a messed up cam gear then I'll gladly assist you in confirming that.

Also, if it is off by a tooth, it's an easy fix correct? Just move it to the correct alignment?