Locking Timing
 

We adjusted my Idle yesterday to a sweet 1000 rpm. We took lots of fuel out at Idle (remember, I'm running a Walbro 255). I'll settle for that considering I've got a BIG streetport and I'm breaking In the Motor. But here Is the thing.

No matter how well we stabbed the CAS, We could not adjust timing to 5 ATDC, or even lock It In at 0 degrees, as suggested from others. I'd line up the Yellow mark to the pin on the Main Crank, start the car up, go to lock timing press Mode - than go for It. Right now, I am 8 degrees off the Yellow pin (If we are to Include the 5 ATDC as prescribed by Microtech). Even offsetting It one tooth off, to counteract the difference, did nil. Could anyone enlighten me as to what may or may not be doing right? Am I still In the Idle map at 1k rpm which would allow me to set timing correctly?

Here you go Bud :D
ready?

remove black cap off CAS
remove 10mm bolt holding cas and pull it (till it's free NOT all the way out)

Move the main pully till the yellow marker is DEAD on with the pointer.
.http://mediaservice.photoisland.com/...9558821315.jpg

Now align the 2 pointers inside the cas with the 2 cap screw holes
http://mediaservice.photoisland.com/...1773949028.jpg

Hold the Pointer steady while you reinsert the cas
it will move a little but thats ok

put 10mm bolt hand tight (enough still where you can move the cas)

Hook up the timing light
go inside car:
Scroll up to the "set up" screen (screen 31) and across to the "timing check" screen

*Switch the handset to program mode & then use the ADJ up/down buttons to set the screen to "timing locked on".This locks the timing(all timing correction values are ignored) so there is no timing advance.

*Check the timing with a timing light & adjust to 5deg ATDC for rotaries.

-Once it lines up

Switch the Timing Check function off again (display reads"timing check OFF",rev the engine & check the timing again with the timing light.Make sure the timing advances as the revs increase

hmm now that I re-read your thread

I don't know if my post helps out
since I posted on how I zero my timing

and your having the problems getting it to lock at 5 degrees? is that correct?

Within your detailed "How To Lock Your Timing Using A Microtech", you forgot to state the crucial element - start your car!;)

Your first post, I found It Interesting how you suggest to stab the CAS with the 2 Gear pointers facing the screw holes. I always thought you line them up to the dimple and marker as per FSM...

With Microtechs directions to lock It In at 5 ATDC, I am off an additional 3 degrees. I'd settle for their prescribed 5 ATDC, right now. After that, I want to zero It In so both my Crank and LT8 read - zero.

The cars fine though. Am I out of tolerance of adjusting Idle at a 1000 rpm Idle?

Just to add:

-The CAS has been stabbed and restabbed. It is fine, and set to factory specs. Trust me when I say that it is right. :)

The issue is that we cannot get less then about 8 degrees advance, no matter how we position the CAS. This one has me stumped, because there is no way the CAS is off...It is dead on. As silverrotor mentioned, we went so far as to purposfully install it one tooth off in both directions just to make sure. The result was that the timing was wildly off (as expected). Rotating the CAS does change the timing, but even with it as far as it can to towards the front of the engine, we are still seeing around 8 degrees. Car runs great, but the timing is still technically slightly advanced.

silverrotor: Yes, you are still at the idle map at 1000 RPM if the TPS reads 0%.

Could it be the issue of a front pulley itself? Dale Clark as told me a few times that Japspec pullies and the stock US pullies are different. I haven't ever looked at this personally but it is a possibility.

Daniel

I was going to suggest that Daniel but deemed It far fetched.:) I figured they are essentially the same Motors and how can the Main Pulley or/and marks vary with the s5 13 BT J-Spec?

One probable cause that we came up with Is perhaps the Crane Cams HI-6 Ignition Box may have disturbed the signal? I posed the question of running an Ignition Box with a LT8 before and I was told that their would be no problem. https://www.rx7club.com/showthread.p...hreadid=187080 I'm just trying to come up with Ideas.

Dale has had about 10 JSPEC engines go through his garage, and he says they are different. I'll get with him to confirm.

Daniel

I do know, for a fact, that the timing marks are different from the '86-88 to the '89-91 pullies. From what I've seen, the hub itself is the same for all, just the inside pulley itself is different.

Generally, with the stock ECU, the rule is run the pulley that matches the ECU. If you have an '86-88 car, run the '86-88 pulley, even with an '89-91 motor.

I really can't remember if the Jspecs are different, and if so how much. I think the real root of the issue is the difference between the early and late cars.

Dale

Thanks for your response. As I mentioned, I have a s5 TII J- Spec Motor rebuilt and streetported with about 500km's on It. The problem from the beginning was setting the timing and It has been since...

I have removed the accessory Pullies ie. Power Steering, A/C and Air Pump than used shorter ss Bolts for a clean appearance. I doubt that this maybe an Issue, so It's not worth mentioning.

Dale, you suggest to match the Pulley to the ECU. But how could the use of my J-Spec not be suited for the LT8, In terms of timing control? Am I missing something?

Silver

My motor is a s4 J-spec, i have no problems with getting it in the right spot,

when you put the timing lock on and move the CAS does the timing mark move??

i dont think the crane would be causing any issues unless it is set to change the timing figures,

does it have a boost retard or anything like that on it??

have you tryed to bypass the crane and see if that works

Dale

I haven't gotten around It today. Too bad...It'll probably be around the weekend when I do. When I turn the CAS, when the Timing Is set on Lock On, It does show a response. The Yellow Mark draws Itself closer to the pin when I bring the CAS closer to the front of the car. Eitherwise, It stays hidden underneath the Water Pump pulley.

I am sure that the Crane Cams HI-6 Is wired In correctly. I notice no erratic Ign or Idle. Besides, the LED Indicator pulses In sync to the rpms. The dials are set on zero Indicating rev limiter Is off.

I may have to bypass the Ign Box to see If this corrects It. Nobody Is running an Ign Box along with a Microtech?

I sure hope the IGN BOX does not affect the microtech, cause that is my plan instead of upgrading the current coils with the bosch ones should i ever require the extra umph!

Well, If anyone vouchs for the use of a Microtech and the use of an Ign Box, I may come to terms with wtf Is going on.:) Eitherwise, I'll assume It's the wiring to It or/and the Pulley.

ok so you oull the CAS to the front of the car and it moves from under the pulley to the yellow mark?? pull the cas out and move it one tooth around and see if you can get it back past the yellow mark, you should be able to, i have done this before and it has always worked

on my car i just use a booster on the leading coils, it changes the voltage to the coils to 16v gives it a heap more spark, i know of people using MSD's and stuff with no problems at all, im guessing it is just 1 tooth out still,

Dale

There's no way the ignition box advances the timing. :D Think about it. :)

are you using the trailing or leading when checking the timing?

This topic is 4 years old. The problem was long ago solved by just grinding out the adjustment slot in the CAS.

Exactly. :D