Cam raw not changing

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Posts: 16
Joined: Thu May 29, 2014 5:58 am

Cam raw not changing

Post by sicup2 »


I have a problem with 720 sync on an Evo 5 with a Mivec Engine. Car has an 18-1 crank trigger, the standard cam triggers and had been running ok on its first event after upgrade (albeit with low boost).

Exhaust cam (phase) utilises Analogue input 06, and Mivec Cam utilises Analogue input 03.

I noticed we had lost 720 sync and noticed the cam raw was not changing as it previously had.

Sync log shows good cam phase signal, but cam raw remains steady when viewed on guage and on datalog. Can this be anything other than an ECU problem??

I have tried swapping inputs and both cams give good signal when connected to input 06, but no signal to input 03 suggesting wiring or ECU issue with input 03.

I have also tried disabling the Mivec function (taking Input 03 out of use) and still Cam raw on Input 06 does not change.

Anyone have any ideas??

Steve C
06 input to mivec cam.txt
(291.06 KiB) Downloaded 178 times
03 to exhaust cam.txt
(283.84 KiB) Downloaded 186 times
06 to exhaust cam with mivec disabled.txt
(238.89 KiB) Downloaded 194 times

Posts: 867
Joined: Sun Dec 07, 2008 2:04 pm

Re: Cam raw not changing

Post by stevieturbo »

Open up a gauge showing raw values for AN3 and AN6 the two inputs you refer to.

Apply 5v to each pin and see if the gauge shows this change. That will test both the input and wiring.

Assuming you already have a 5v supply to each of those sensors, it'd just be a case of bridging a wire from 5v to the signal input ( dont short across to ground though lol )

And has this ever worked correctly ? Is it a new build ? other ?

And is phase definitely configured off the exhaust cam ?

For a cranking test, you could disable the injectors for safety, and switch ecu inputs 3/6 about and do a sync scope to see if you're getting a waveform. Do not try that without disabling the injectors so the engine cannot attempt to start.

Zen Performance
Posts: 406
Joined: Mon Aug 04, 2008 9:18 am

Re: Cam raw not changing

Post by pavlo »

Cam phase comes from the exhaust cam and will be static on single MIVEC evo head.

You want to look at VVT1inRaw which is what you should use for fine tuning latch angles for the VVT.

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