Long tooth gap after COP

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Matty
Posts: 2
Joined: Wed Sep 10, 2014 2:20 pm

Long tooth gap after COP

Post by Matty »

Hello folks,

Looking for some advice. I've got an Evo VII in with me running an S8 with the recommended Syvecs crank pick up plate and was running perfect before, however it's now had an M&W 14 CDI kit fitted, wiring has checked out fine - there was a few small issues but now rectified, I didn't wire the car however it was 90% right.

I've done everything correctly, thanks to Ryan - ignition set to normal and dwell at 0.30ms - and it does offer to start and if I disable manual cam check list it will start and run in 360 sync - albeit not great obviously. I've pulsed the coils though the M&W and the S8 and they spark perfectly.

I'm constantly getting a long tooth gap sync fault - I've checked the wiring to the crank sensor and it checks out fine, so before I diagnose the cranks sensor as being faulty I have a gut feeling it's something I have or haven't done right - I'm sure pull down resistors have been mentioned before, but again I can't remember.

Thanks,
Matty
stevieturbo
Posts: 1321
Joined: Sun Dec 07, 2008 2:04 pm

Re: Long tooth gap after COP

Post by stevieturbo »

magnetic or hall sensors ?

scope trace ?

Has it ever run with the config you are using ? Or an engine like it ?
Matty
Posts: 2
Joined: Wed Sep 10, 2014 2:20 pm

Re: Long tooth gap after COP

Post by Matty »

Hello, thanks for the response.

Hall sensors.

Scope trace is on my laptop, which I've left at work - I'll post up tomorrow.

Other than changing to the M&W set up, the car ran perfect with this calibration.
stevieturbo
Posts: 1321
Joined: Sun Dec 07, 2008 2:04 pm

Re: Long tooth gap after COP

Post by stevieturbo »

If it ran correct before and sync'd, then something relating to crank/cam triggers must have changed

If both are hall, trigger levels and cranking speed shouldnt be a issue. Nor even interference if the CDI was doing something strange. Unless there are HT leads routed very close past one of those sensors ?

Could you not just fit some decent coils instead of bothering with the CDI ? Can you bypass ( or just disable ) the CDI to see if it will sync up ? At least that would rule out the CDI unit itself as part of the problem if it still fails to sync.

Although if it was running manual cam checklist, perhaps trigger/angle settings were borderline and they've shifted a little somehow which would stop it syncing.
Is the cam sensor movable, or was it moved ? cam wheel or cam if read from that ?
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