SR20 CAS question

[doridoridori]

So recently was diagnosing a headache of an issue I got solved. In the process i originally assumed it was my CAS that was bad, turned out to be bad wires that went to the connector.

The question I had was if anyone else had this "issue" if you can call it that. so after fixing the cas connector wires car fired up and when installing a new cas I lined up the dots, stabbed the cas, even took the valve cover off and saw the dot lined up with the mark on the CAS. I remember in the past people saying usually when it's spot on the bolts will sit in the middle which should be right. When I used a timing light to get it set to 15deg. it doesn't sit still (the mark on the crank pulley) until it's almost all the way retarded or advanced (me turning the cas clockwise). Does that sound correct?? it idles smooth, doesn't breakup and drives normal but just wanted to double check.

[TheRealSy90]

If you aren't in "timing mode" the ignition timing will walk around even at idle. It's a pain but you need to try and get the ecu to go into timing mode. There's a bunch of ways to do it and none ever seem to work consistently lol. There used to be a old website with sr20 set up tricks for getting any stock sr to run great but it seems to be down now. Or the link isn't working for me: https://www.plmsdevelopments.com/ind...r20-setup-tips

[S14rebuild]

Easy, start car, disconnect tps sensor, then rev the motor a few times past 3000rpm....this will lock the ecu in timming mode, and allow u to adjust timing at idle. Once done. Plug tps back in. N good togo. Ive always done this once the car is at operating temperature.

[brndck]

Originally Posted by TheRealSy90

There used to be a old website with sr20 set up tricks for getting any stock sr to run great but it seems to be down now. Or the link isn't working for me: https://www.plmsdevelopments.com/ind...r20-setup-tips

the site is still up, but you get that "this site is not secure" error message, then you have to click "proceed anyways"

[TheRealSy90]

Originally Posted by S14rebuild

Easy, start car, disconnect tps sensor, then rev the motor a few times past 3000rpm....this will lock the ecu in timming mode, and allow u to adjust timing at idle. Once done. Plug tps back in. N good togo. Ive always done this once the car is at operating temperature.

That’s what’s supposed to work but I’ve had it not work a few times in the past. Basically just turned the car off and on to reset and try again.

Originally Posted by brndck

the site is still up, but you get that "this site is not secure" error message, then you have to click "proceed anyways"

That’s what I was getting but there was no proceed option. Probably due to my work firewall idk.


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[doridoridori]

Originally Posted by TheRealSy90

If you aren't in "timing mode" the ignition timing will walk around even at idle. It's a pain but you need to try and get the ecu to go into timing mode. There's a bunch of ways to do it and none ever seem to work consistently lol. There used to be a old website with sr20 set up tricks for getting any stock sr to run great but it seems to be down now. Or the link isn't working for me: https://www.plmsdevelopments.com/ind...r20-setup-tips

damn had no idea, all i did was let it warm up to about 160*F then unplugged the tps and hit it with a gun, using the loop on the back of the coil pack harness. Ive even heard some ppl say the loop doesn't work accurately so some ppl grab a spark plug wire, put it inbetween the coil pack and plug and use that to set timing haha. The engine felt a little hotter than it should to the touch which is where my concern came from. as it is right now it idles smooth and revs fine but i want it to be 100%

i can't get that link to come up.

[doridoridori]

Originally Posted by S14rebuild

Easy, start car, disconnect tps sensor, then rev the motor a few times past 3000rpm....this will lock the ecu in timming mode, and allow u to adjust timing at idle. Once done. Plug tps back in. N good togo. Ive always done this once the car is at operating temperature.

cool i'll give that a shot, appreciate the help once again!

[doridoridori]

Originally Posted by S14rebuild

Easy, start car, disconnect tps sensor, then rev the motor a few times past 3000rpm....this will lock the ecu in timming mode, and allow u to adjust timing at idle. Once done. Plug tps back in. N good togo. Ive always done this once the car is at operating temperature.

man this made all the difference lol every SR guy i know close in my area never mentioned locking the ecu in timing mode but once it was warmed up, I unplugged the tps, revved it about 3-4 times on the 4th time it sounded like it was holding to the rpms i revved it at, then I hit it with the light and the marks on the crank pulley were all the way to the left. I had a feeling with how hot to the touch the engine felt I knew it was something up with the timing.

Gonna let it cool down a bit, test drive it ini a few and see how it feels. However instead of the bolts being all the way one way, it's a lot close the exact opposite but maybe that's how it's supposed to be idk.

[Kingtal0n]

The way I always do it works fine

1. unplug tps and start engine (or unplug on running engine idt it matters)

2. hook the timing light to the coil pack wire like this

https://zilvia.net/f/showpost.php?p=6191153&postcount=4

Let me know if you cant get the picture to show clearly I can find it on my old drive and re-upload

3. Finally, recognize that timing lights are often directional. In other words, if you flip the pickup -the clamp- it can read a completely different number.

the way to tell which way is 'right' is that the CAS will be nearly center -not quite but almost- with the timing reading 15* btdc. If you pickup is "reversed" the cas will not be center when you see 15 at the crank

rev the engine lightly, no more than 3k, and make sure the timing goes right back where it was each time, pretty rock steady. If its jumping around you have the tps plugged in, or something is up with the TPS signal.

[doridoridori]

Originally Posted by Kingtal0n

The way I always do it works fine

1. unplug tps and start engine (or unplug on running engine idt it matters)

2. hook the timing light to the coil pack wire like this

https://zilvia.net/f/showpost.php?p=6191153&postcount=4

Let me know if you cant get the picture to show clearly I can find it on my old drive and re-upload

3. Finally, recognize that timing lights are often directional. In other words, if you flip the pickup -the clamp- it can read a completely different number.

the way to tell which way is 'right' is that the CAS will be nearly center -not quite but almost- with the timing reading 15* btdc. If you pickup is "reversed" the cas will not be center when you see 15 at the crank

rev the engine lightly, no more than 3k, and make sure the timing goes right back where it was each time, pretty rock steady. If its jumping around you have the tps plugged in, or something is up with the TPS signal.

I clicked the link but it is blurred via photobucket, also thought you're supposed to put the clamp on the loop by the back of the coilpack harness, no??

[S14rebuild]

Best ive used is an old spark plug wire, on end clips on the plug, other end i cut uff and expose the electrode wire, stick that in the coil. That way i have a solid spot to connect the pick up too n have no interference or issuses.

[doridoridori]

Originally Posted by S14rebuild

Best ive used is an old spark plug wire, on end clips on the plug, other end i cut uff and expose the electrode wire, stick that in the coil. That way i have a solid spot to connect the pick up too n have no interference or issuses.

yea i've done that before, I was trying to find one but didn't have any luck don't usually have spares but i've heard some people swear up and down by the wire on the back of the coil pack harness but i've heard some ppl say it isn't as accurate. Going to try to find a wire to use for that

[cotbu]

Sorry for just jumping into this, but the proper way to remedy this issue, would be to set the engine to TDC and reinstall the CAS per FSM. And since you learned timing mode and are able to determine which method of shooting time works best for you, I say do it.

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[Kingtal0n]

Originally Posted by doridoridori

I clicked the link but it is blurred via photobucket, also thought you're supposed to put the clamp on the loop by the back of the coilpack harness, no??

a. click the picture to goto the full photo I just did it works fine

b. the timing loop at the back never worked for me, probably because i use a cheap 20 year old timing light.

c. Ive seen newer, expensive higih quality timing lights that were amazing, some that you can just touch the pickup to the top of the coilpack and it works

[doridoridori]

Originally Posted by cotbu

Sorry for just jumping into this, but the proper way to remedy this issue, would be to set the engine to TDC and reinstall the CAS per FSM. And since you learned timing mode and are able to determine which method of shooting time works best for you, I say do it.

Sent from my moto e5 plus using Tapatalk

it's all good and no disrespect but i wouldn't be checking with a timing light if it wasn't stabbed at tdc lol that was the first thing i did. Took the valve cover off and the dot on the gear is lined up with the mark on the cas so i know it's spot on at this point, just a matter of getting it 100%

[doridoridori]

Originally Posted by Kingtal0n

a. click the picture to goto the full photo I just did it works fine

b. the timing loop at the back never worked for me, probably because i use a cheap 20 year old timing light.

c. Ive seen newer, expensive higih quality timing lights that were amazing, some that you can just touch the pickup to the top of the coilpack and it works

ok just did it, so you put the clamp around the white wire only? from how it looks. Never seen anyone do it that way but if it works it works. Gonna try to get my hands on a more expensive timing light as well, on the 3rd try I got it a bit better but a little sluggish. I imagine might even have to mess with the idle adjust a bit too, to get it spot on.

[S14rebuild]

Ive done the loop too and never had an issuse..just used the single white wire.

[doridoridori]

Originally Posted by S14rebuild

Ive done the loop too and never had an issuse..just used the single white wire.

why is it just the single white wire? i always seen ppl put the clamp around all the wires that go to the coil pack connector but im glad i posted this because Im learning a lot and it also tells me everyone i've spoken to locally maybe their cars are all out of time haha

[S14rebuild]

That was years ago i did it that way.

Bout few months ago i was checking/setting tining on my sr after cam swap and i used a cheap-o timing light. Couldnt get it to work off the white "hoop" wire or the entire harness going to cyl1 coil. Had to use a spark plug wire to get it to work properly.

At this point id just say all 3 ways work but would depend on the quality of the timing light used.

[doridoridori]

Originally Posted by S14rebuild

That was years ago i did it that way.

Bout few months ago i was checking/setting tining on my sr after cam swap and i used a cheap-o timing light. Couldnt get it to work off the white "hoop" wire or the entire harness going to cyl1 coil. Had to use a spark plug wire to get it to work properly.

At this point id just say all 3 ways work but would depend on the quality of the timing light used.

ah gotcha well i'll try all the methods above to get it right, obviously you never want the timing to be off but if it's a little off is it that detrimental to the well being of the engine? i'd imagine so but i'll get my hands on a spark plug wire and get it right

[S14rebuild]

Timing is EVERYTHING

[Kingtal0n]

Originally Posted by doridoridori

obviously you never want the timing to be off but if it's a little off is it that detrimental to the well being of the engine?

make sure the timing accurate within 1* or so. It is very important... yes.


If I tell the computer 9* and it does 10* instead this can be a huge problem

same thing if I command 9* and get 8*.

In the first place, if the torque is high enough it may hammer the rod bearings or take flakes of aluminum from the piston surface
In the latter it could raise egt and throw 18% or more torque away, also potentially melting the manifold, ruining the coating, or starting a fire.

Those are extreme examples -say 28 to 32psi of boost on a methanol/gasoline- but it illustrates the importance of knowing 'where you are'

[doridoridori]

Originally Posted by Kingtal0n

make sure the timing accurate within 1* or so. It is very important... yes.


If I tell the computer 9* and it does 10* instead this can be a huge problem

same thing if I command 9* and get 8*.

In the first place, if the torque is high enough it may hammer the rod bearings or take flakes of aluminum from the piston surface
In the latter it could raise egt and throw 18% or more torque away, also potentially melting the manifold, ruining the coating, or starting a fire.

Those are extreme examples -say 28 to 32psi of boost on a methanol/gasoline- but it illustrates the importance of knowing 'where you are'

Yea good point, i figured it was important just wanted to make sure it was spot on. I did get it sorted out, I used a spark plug wire betten the plug and coilpack and it seemed to be more accurate that way. Strange that SR's has to be the only engine I timed that had multiple ways to try and time it and it doesn't always work the same from one person to the next. Some say the hoop in the back of the coil pack harness works and for others it's inaccurate. Either way I did both methods and got it spot on, appreciate all the info