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-   -   weird ignition timing (https://www.rx7club.com/2nd-generation-specific-1986-1992-17/weird-ignition-timing-1129990/)

wongfei 09-15-18 11:41 AM

weird ignition timing
 
The problem is when I use strobe light connected to L1 the notch on pulley doesn't align with pin. But the CAS is perfectly adjusted to right notch. So I'm not getting something OR the notches are wrong? (idle around 700-800, TPS adjusted to 1kOmh, probes almost perfect 1V)

https://cimg7.ibsrv.net/gimg/www.rx7...97bb51a99c.jpg
https://cimg0.ibsrv.net/gimg/www.rx7...453ec60f45.jpg
https://cimg9.ibsrv.net/gimg/www.rx7...f083b0a7ab.jpg

L1 strobe:
https://cimg8.ibsrv.net/gimg/www.rx7...491c4e38c9.jpg

T1 strobe:
https://cimg6.ibsrv.net/gimg/www.rx7...8234fda174.jpg

I tried to adjust CAS when engine running and when right notch matches the pin it works VERY bad and sometimes dies.

NCross 09-17-18 05:44 PM

Has someone rebuilt the engine and used the wrong pulley? It happens on 1st gens all the time.

Templeton 09-20-18 08:09 PM

Agreed with NCross, I just ran into this issue myself with my fc. I read that this is because the pulley and hub are paired and then drilled randomly, so if a pulley and hub are mismatched the timing marks are no longer accurate. The cheapest way to remedies this is to buy a known matched pair. I believe rotaryevolution used to sell them. The other choice would be to buy racingbeat aluminum main pulley, though it is an underdrive so that's also a consideration.

professionalpyroman 09-20-18 10:25 PM

Hey, just curious, does this sequence sound familiar?


When you adjust the timing, you slowly approach the timing mark, the engine seems to get better and better, and then goes full stupid, and the timing mark disappears?
When you adjust the throttle position sensors, they seem to lose their place after a while?
If you get it adjusted close, does it have a completely different timing when you remove the test jumper?

NCross 09-21-18 06:38 AM

If it were me, I would remove the left side flywheel inspection plate and set the engine at TDC then make my own timing mark.

wongfei 09-22-18 11:17 AM

found new TDC using oil in rotor method (+ rear rotor method):
https://cimg8.ibsrv.net/gimg/www.rx7...d6ea1a53c9.jpg

https://cimg7.ibsrv.net/gimg/www.rx7...2d22c67b84.jpg

marked new 5 ATDC and aligned CAS:
https://cimg9.ibsrv.net/gimg/www.rx7...e9f93e076d.jpg

rewired CAS with quality 4 core shielded wire away from coils
and same shit on L1, resulting timing is about 15 BTDC:
https://cimg4.ibsrv.net/gimg/www.rx7...fb2955ac3d.jpg

the question is: when i have a perfect 5 ATDC mark and perfectly aligned CAS to that mark, should the timing light on 750 match the pin without any hacking? or i don't get something?

Hot_Dog 09-23-18 12:50 PM

Hey, I got a quick question on this too. I tried to do a quick timing check on my S5 over the weekend and wasn't able to see any paint marks on the pulley. There used to be paint marks on my pulley. Are there "V" notches in the pulley where the paint marks are supposed to be?

NCross 09-23-18 02:23 PM

Yes. There are little indentations on the pulley where the paint used to be. I usually put a dab of yellow and red paint on them.

Hot_Dog 09-23-18 05:06 PM


Originally Posted by NCross (Post 12302947)
Yes. There are little indentations on the pulley where the paint used to be. I usually put a dab of yellow and red paint on them.

Thanks, appreciate it!


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