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stony

RB CAS drive gear replacement info.

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I took the car back to the shop this afternoon to get them to show me how they were getting the timing signal. They were using the same gun as mine but they were pulling the signal from the looped wire at the back of the coil pack harness which I have been avoiding because everyone says not to and to use the wire extension method from coil pack to plug. I do believe that the FSM says to use the looped wire at the back of the coil pack but on mine the light flash really fast which means it is picking up signal from all 6 coils not just cylinder 1. We did however notice that there is a big difference in results between the looped wire method and the extension wire. The tech hooked up to the looped wire and it read 3 degrees and mine hooked to the extension read -4 degrees. The tech also thought that the 3rd mark on the crank was 15 degrees but I have corrected him and told him that it is the 4th mark.

 

I will see what I can do about adding another ground wire tomorrow.

 

The issue that I am having is not that the ECU is pulling timing at any certain RPM but that I am getting negative timing numbers from the light at idle while setting base timing.

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I replaced the cas drive pin with the one that Stoney got from JWT as mine was broken and I had just started looking back at threads I posted on earlier in the year to figure out if this problem started before or after I replaced the drive pin. I don't think I ever really messed with the timing until I got the idling problem sorted out which I believe was after I replaced the drive pin. I used the instructions from JWT and installed it back wards as Stoney had mentioned in his thread. When I installed it I remember looking at it and thinking it might not be exactly aligned in the center of alignment dow but I figured the adjustment in the CAS slot will make up for that. I pulled out a spare cam that I have last night that also has a broken drive pin and I noticed that it is not aligned exactly center on the cam dow either but it is out the other direction which now leads me to believe that the total difference could be 10-15 degrees. 

 

If anyone has an extra cam laying around or if they have their cam gear off for some reason it would really help me to confirm this theory if I could see the drive pin alignment of another stock cam. 

Edited by Vandergriff84

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OK, so after having come to the conclusion that it is possible that the CAS drive pin could be aligned incorrectly I went ahead and removed the three bolts that hold the CAS on, so that I could move it further than the slots would allow and I was able to advance the timing to 15 degrees. I was able to plug the tps back in and the timing still held at around 15 degrees. The question is can the drive pin be out this much? Keep in mind that the exhaust cam is currently advanced one tooth so this should already be compensating(by compensating I mean helping the CAS to read a more advanced position) some for the drive pin if it is in fact incorrect. When I put the three bolts back in and advance the CAS all the way it only shows 10 degrees.

 

It would be super awesome if some one could post a picture of a stock cam drive pin alignment. =) 

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Thanks flatrate, I think this confirms my suspicion. JWT directions say to align the half moon with the center of the cam gear alignment dowel but in the spare that I have it looks like it is a little more to the right side of the dowel as it also looks in your picture and another that I have found online. It appears that I installed the new one a little to the left of center on the dowel. I never would have thought such a minute difference would make such a mess when the CAS has adjustment in it. I guess stony didn't have this problem because he has the magic box. For now I am going to open the slots a little on my CAS to see if I can get it to 15 before I go through the process of replacing the drive pin.

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Ok, So to confirm my suspicion from my last post, the cam alignment key was out just enough to keep me from getting the sensor advanced past zero. For now I have just opened the adjustment slots on the CAS so that I can advance it further to 15 degrees. I apologize for the rabbit trail that this thread has gone through and I appreciate everybody's help with figuring this out. I will make a comment on the pinned thread that Stony started about the correct position for the drive pin so that the next guy going through that process with a stock ECU will know what to watch out for. For those who have standalone ECU's this isn't a big deal because you have the ability to change your phasing I believe.

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Ok, So I had done the JWT drive pin several months ago while I was still trying to get my idling down to stock specifications so that I could correctly set the base timing and I wanted to let everyone know that plans on doing this with a stock ECU to be careful of the placement of the drive pin. I believe that the instructions from JWT are a little off and the reason for this is because after inspecting other stock cam drive pin alignments it appears that the correct alignment is just to the right of center on the dowel pin and not dead center on the dowel pin as the instructions say from JWT. I came across this as I've been trying to figure out why I couldn't get my base timing advanced above zero and after pulling out all my hair for the last six months thinking that the ECU was retarding the timing even in base mode. I started to question the installation of the drive pin and when I had checked to see if mine was installed correctly I had seen that it was just a hair to the left of center on the alignment dowel but I figured that it wouldn't matter since the CAS should have 30 degrees of adjustment. Well the CAS does have plenty of adjustment but the small amount of inaccurate placement on my part combined with the slight inaccuracy from the instructions from JWT kept me from being able to advance past 0 degrees in base mode which left the car running rich and making very little power. I did this installation with the cam still in the motor which led to the slight misplacement on my part and I would recommend that any one looking to do this plan on taking the cam out as the instructions say and visually make marks for the correct placement of the drive pin based on the stock pin that's broken before you remove it. This way you are sure to put the new one in the correct alignment.

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stony    11

Agreed. especially when using a stock ecu where you cant set the timing. I'm using the aem... in fact when we were on the dyno with my timing set at where i thought it was supposed to be, i had to advance the timing just to got it to go past 5000rpm. SO it was way WAY  more retarded then we thought. 

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stony    11

You have also confirmed that when people say just line the teeth up and put the cas sensor on are wrong. without the half moon in there the cas gear chatters on the drive gear causing pretty big variations in timing. This would explain why my timing while on the dyno would just drop off on the dyno. also would explain why my torque and power curve were never really smooth. at any rate glad you got it figured out.... I never though about notching the cas sensor like that to get the timing back to where it needs to be. Way to think out of the box ;>

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HowlerMonkey    12

Are we satisfying the ecu in question concerning setting base timing and have some way to see that timing on the front pulley?

 

Some ecu of that family have a 5 degree timing change at idle depending on ground to a certain terminal.....usually from the park/neutral safety switch that retards timing 5 degrees.

 

This is on ecus that came from automatic sourced cars.

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Sounds good Stony, I hope this helps someone else out. I had read about three other threads on different sites that describe the exact same problems I was having but no one ever posted a solution so I post on all of them hoping to get a response but none the less I was on my own. I have also read that if the half moon pin is broken that the wondering signal will result in a massive retard in timing from the ECU.

 

Just as a side note to all that are planning to do this swap. Take the time to find a reliable and honest source for the motor before ordering. I bought mine from Canada and when it arrived, everything on the exterior was broken. I know that most of the importers don't warrant against exterior parts being broken but I have spent over a $1000 replacing what was broken on mine and as of now a whole lot of time because the cam drive pin (which is technically attached to an internal part by the way) was part of what was broken. I would also recommend asking for pictures of the motor before ordering so that you know what you should be getting.

Edited by Vandergriff84

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stony    11

Agreed, Best way to go is get it out of a running clip. 9 times out of ten when you get it from japan it has come out of a wrecked car. if it was a front hit there is a good chance the water pump tab on the black will be broken off. 

 

Howlermonkey the conversation about timing was a legit conversation... i weeded most of it out because even though it was accurate it wasn't related to the problem as a whole in this thread. The issues I had and the stuff that V went thru are pretty much everything that could go wrong with the cas drive gear replacement and hopefully will prevent any excessive downtime for anybody in the future.  

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