Timing Issues - Help

Welcome to my ignition timing nightmare.

Ever since I have installed the PONcams I have been unable to get my CAS to 15 Degrees Ignition timing. The Item is fully retarded to one side and the lowest number I can reach is 20 degrees.
I have had my front timing covers off so many times I can do it in my sleep. Everything lines up the crank is at TDC,I even checked this with a marked rod in piston number 1 and slowly cycling the motor to make sure the marks line up.

The cam pulleys are Identical for exhaust and inlet so they can’t cause any misalignment, all the marks line up on the motor so I have no idea what’s wrong,I have dropped a E-mail to Tomei to see what they say but it does look like the “half-moon’ “Cas spline is advanced when compared to a stock Exhaust cam using the Pin as a reference point.

Guys any Ideas are welcome, I don’t know what to check anymore

Why dont you just break the locating pin off your brand new set of Tomei cams and move it back a tooth? 😛 😛

Are you reading the 20degrees on the laptop or on the crank pulley?? I have a good few sx's come in and the keyway in the pulley is worn and this give false readings. Rather check on the ECU than on the pulley to be safe.

The Tomie cams could look advanced in comparison to stock cams because they may have changed the cam timing in factory so you dont have to use vernier pulleys.

Are you reading the 20degrees on the laptop or on the crank pulley?? I have a good few sx's come in and the keyway in the pulley is worn and this give false readings. Rather check on the ECU than on the pulley to be safe.

Both, I get the same reading

The Tomie cams could look advanced in comparison to stock cams because they may have changed the cam timing in factory so you dont have to use vernier pulleys.

Pon cams are degreed but the Spline and half moon for the Cas should be cut correctly so the CAS sits in the middle and not at 20 Degrees at full retard. I can’t see tomei making a F-up like that

I highly doubt a company like Tomie has make a screw up like that, if they did many people would has said something so a quick google would find something.

Are you 110% sure the cam timing is correct??

Are you 110% sure the cam timing is correct??

Shit Dude, I have double, triple checked it but let me post pics maybe you can see something I am missing

But I dont think its out becuase the car starts smoother and pulls damn hard

But I dont think its out becuase the car starts smoother and pulls damn hard

Yeah but maybe because they are degreed you dont notice it as much as if it were stock cams...

I found that if you mark the back of the tooth it really makes it easier to get the timing spot on...

Yeah but maybe because they are degreed you dont notice it as much as if it were stock cams...

I found that if you mark the back of the tooth it really makes it easier to get the timing spot on...

You’re seeing things the same way I did, I have checked the timing so many times it’s scary but let me post the pics and you can check as well.

I mean I even checked my Crank TDC

something similar happened to me when changing to DE cams, and it turned out to be a PEBCAC error!

there was a scratch on the cover that goes against the head. the one you use to reference TDC on teh top of the motor. this scratch was on the exhaust side, where the cas goes in.

the scratch was one tooth ahead of the normal timing mark, and it screwed me around numerous times!

so... are you absolutely positive "POSITIVE" that you have set the crank and cams at TDC???

After VC told me to check my cam timing when i put my head back last time, i went and counted the teeth and set the timing that way ,a bit of a slep but its right then.

yup - its actually so easy to cock up the timing on the cams with the ca18.

check the FSM - you'll get the tooth count, that really helps, usually only if you have the at least one of the reference points correct. but im sure you already knew this! 😉

Howzit Guys

As promised here are the pictures sorry about the bad crank picture.
I have counted the teeth all match the FSM

Your not on tdc buddy. Take the crank pully of and coun't from the mark on the timing belt pully itself.

Those timing marks look spot on, either it is out on the crank or that is how the cams are made...

Your not on tdc buddy. Take the crank pully of and coun't from the mark on the timing belt pully itself

? Thats TDC Honestly 😂

Those timing marks look spot on, either it is out on the crank or that is how the cams are made...

Counted teeth like I said and the crank sprocket matches up, But I did kind of resolve the issue, I am now on 15 degrees and it must just stay there.

Like I said the spline and half moon for the CAS on the tomie cams is not in thte same location as the stock exhaust cam it slightly advanced and I don’t know why. I have picture of that as well that I will post

you sure that bottom cover plate is not bent somehow? i've also had that issue before!

if it were me, i would only be 100% if i could see the bottom sprocket, but thats a big mission!

veecee wrote:

you sure that bottom cover plate is not bent somehow? i've also had that issue before!

if it were me, i would only be 100% if i could see the bottom sprocket, but thats a big mission!

A mission ,but the rite way.

if it were me, i would only be 100% if i could see the bottom sprocket, but thats a big mission!

I get what your saying and I do agree but I know the timing mark on the Crank pulley and sprocket are correct, I have manual checked them and checked the reference with the pulley on and the sprocket lined up.

I really think its something with the cams, I mean I have done timing on the CA18 about 30 times and I have never had this shit.

But unrelated I am looking over the logged data and there is some interesting stuff here

Pinkfluffybunnys wrote:

But unrelated I am looking over the logged data and there is some interesting stuff here

Please do share.

So the CAS spline is advanced in the exhaust cam, could this possibly be to allow you to retard the exhaust cam with a vernier pulley and still have some adjustment on the CAS? But it doesn't make sense that the CAS is outside of its normal range with the cam set to standard.

To me it sounds like a manufacturing issue with the cam, it may not have been indexed correctly when the CAS spline was formed.

Perhaps a custom CAS mount is required? One that does away with the front cover. 😉