Cam sensor troubleshooting

Give input on tuning as well as any tips and tricks you may have. Also feel free to share base mapping files for various engine types.
FrankCorrado
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Re: Cam sensor troubleshooting

Post by FrankCorrado »

The SDS ECU relay, the one that was required to use for my other ECU wiring. It's a standard 30A relay. I will bypass it first. I will play with coil ms as well. Those 2 things are super easy to test. Then I will change my ht leads for RFI suppresion ones. Then I will get an OEM harness. But like I said Kev, nothing in my engine is plug and play. Even the OEM stuff are not, cuz I had to customize too many things for my old SDS system so I ended up destroying the OEM stuff in a way that fitting OEM stuff back is no more plug and play and requires a lot of time, efforts and customization. So I'll go one step at a time, easiest to most complex.
Frank
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FrankCorrado
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Re: Cam sensor troubleshooting

Post by FrankCorrado »

86sixsix wrote:can you rotate your engine by hand with a bar on the crank or something and 'rock it' back and forward to check the cam pulse / errors without the motor running?
Sure I can, I thought about it. But I decided not to do it cuz I think this is already tested anyway. Up to 4500rpm under vacuum (did not try above) I get no errors at all, so I figured at 10rpm under no load I would get no errors as well. :D Otherwise it would not makes sense.
Frank
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Re: Cam sensor troubleshooting

Post by VR6Turbo »

Have you got any noisy circuits connected to the S80 sensor ground? have you tried it with and without the cam signal mask? Have you taken the cam sensor out to look for signs of contact with the trigger wheel?

You seem hung up spark plug RFI etc but it's not that. It can't be. Same engine, same leads remember. Forget the bitty stuff it won't be and focus on the bigger stuff it will be.
FrankCorrado
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Re: Cam sensor troubleshooting

Post by FrankCorrado »

Noisy circuits like what? I only have what's in the S80 diagram connected to the ECU grounds.

Yes without the mask it was detecting triggers way off the 56th, but that was before I moved away the wire from the coils, so I'd have to retest without mask. Though that still would not explain the relation with load and no load. It's rpm+load related, not just rpm.

Yes I checked the cam sensor for contacts and also tried another one they both came out in the shape they were when I fitted them in. I will try using a spacer on the sensor to extend the distance between the wheel and sensor, who knows. That's another easy thing to test, but I doubt it is that cuz the parts are all OEM.
Frank
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86sixsix
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Re: Cam sensor troubleshooting

Post by 86sixsix »

FrankCorrado wrote:Sure I can, I thought about it. But I decided not to do it cuz I think this is already tested anyway. Up to 4500rpm under vacuum (did not try above) I get no errors at all, so I figured at 10rpm under no load I would get no errors as well. :D Otherwise it would not makes sense.
you know...that's a damn good point :D - but if you get a bit of time spare - i'd do it and interfere-with-by-hand all the assorted sensors whilst it's going on...jiggle and wiggle everything, rotate the throttles, put a foot pump on the map sensor and so on and so on. and have a big tick-list you can work down and go 'yep, that's perfect'. make sure like when you go past a certain throttle angle or engine stroke the ecu voltage doesn't start going all silly etc etc.

you're not blowing any goop over any of these triggers at high rpm? they all shiny and clean still?
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FrankCorrado
Posts: 120
Joined: Tue Jul 26, 2011 7:45 am
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Re: Cam sensor troubleshooting

Post by FrankCorrado »

You're right, we never know. And I'm the first to say that. :)

Actually not so far, I did check for unwanted substances around, especially under the cam cover and around the sensor/trigger. Only oil and only one type of oil. No leaks, no fuel, no grease, no loctite, no cocking, or anything else. Same for engine itself, pistons and intake manifold, etc. I did clean my ISV months ago when it was full of soot, but I checked it again and it looks pretty clean!!! I'd say only 10% sooted.

Plugs look fine too, a bit off on fuel of course, but no oil deposits or any other weird explosion situations (detonation, coolant, etc.).

It starts to get very cold here so I am in my last weeks of testing until March, hopefully I can try all I want. Good news is no snow yet. Stupid snow... loll
Frank
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FrankCorrado
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Re: Cam sensor troubleshooting

Post by FrankCorrado »

Ha! Well I'll be damned.

The problem is now less important than before, but it's intermittent! I hate intermittent problems.

I increased coil ms to 3.4, from 3.
I use EXTERNAL coil amps, BTW, so the OEM VW coil pack builds up the current, like you Kev.

I tried a 60TPS in 3rd at water of 68 to 3600rpm and no prob.
I did 2 others like that, and 1 in 6th, no prob. Then later on in 6th around 3000rpm I went to 60TPS, 1sec later and at 3225rpm I got 1 cam error. A tenth of a sec later I got 3, another tenth later I got 2, so 6 errors within 2 tenths of a sec. At 3250rpm, water 71.

Now later at water 76 I did a 2-3-4-5-6 from 50TPS to WOT in the last 3 gears for 19sec up to 5700rpm. No errors at all. I smoked a stupid Mazda 3 with a rice muffler.

So then I decided to drop the coil ms down to 2.8.
I went off for a ride. Tried a few times (4-5-6 from 50TPS to 80 and that stuff up to 4600rpm) and only once I had 2 errors in 6th at 3300rpm, 200kpa and 69TPS at 72 water. But right after I tried another one up to 3800rpm, 211kpa and 75TPS, no errors. The timing was 20.x-deg, though on the last one, but it was higher on all the others with errors.

Kev, is 22.6-deg at 3300rpm and 200kpa too much??
My other cam error happened at 186kpa, 3200rpm and 25.7 deg.
Others happened at 193, 3250, 24.3, and 197, 3100 and 26.3-deg!
I think there is a pattern here. I checked the other times I 50TPS+ under boost and timing was never that high above 180kpa, it was under 22-deg.

So water is no the culprit. Coil dwell is also not what causes my cam errors. Since it now works fine at 2.8ms I will keep that one and maybe try to lower it.

I also put back my resistor plugs, so the type of plugs is not what causes my cam errors. The wire is also much farther away from the coil, maybe that helped, but now it's intermittent, so it's harder to pin point.

Maybe I have too much timing at a certain MAP+RPM?
I will anyway adjust that, cuz those numbers are too high for what I used to have on the engine, I am not comfortable what that. I'll try something drastic, like 20-deg for anything over 150kpa.
Frank
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FrankCorrado
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Re: Cam sensor troubleshooting

Post by FrankCorrado »

Nope, not timing related. :) I'll move on to the next steps.
Frank
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Re: Cam sensor troubleshooting

Post by VR6Turbo »

22deg @ 200KPA is a touch high, but it depends what fuel you're using. 20 would be safer and the power drop (if any) would be barely noticable. I always found my VRT was smoother with less timing as we discussed!

You know, I was getting a bunch of crank errors on 50 mile test ride yesterday, which caused 5 resyncs (not nice at over 5000rpm, scares the sheet out of you). Prior to this it had done 100 miles without a single error, so I know it can't be wiring, which it isn't.

So I pulled out the crank sensor and it had a load of swarf stuck to it. Drove it this morning and not a single crank error.

So what I'm trying to say is don't overlook the obvious. Have you tried a new sensor? A new one from VW that is, not one that's been lying around your garage for 10 years! :D

I also get the impression the DTA is a touch fussy with signal quality. My sensor didn't exactly have a Mussel beard of swarf hanging off, just a very small amount, but it was clearly enough to corrupt the signal!
FrankCorrado
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Joined: Tue Jul 26, 2011 7:45 am
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Re: Cam sensor troubleshooting

Post by FrankCorrado »

Yes I noticed yesterday that it seemed to be more powerful with 20-deg and 22 instead of 28 at some other places (150kpa). Weird, cuz it doesn't detonate at the higher timing but hey who cares, if it likes that (low timing) I like it too.

You lucky! You solved your issue so quickly. loll I tried 2 sensors, both are as clean as brand new ones. One was new from last year and ran fine the whole summer. The other one has been used for 5mins in a test VR, that's all I know. Not sure I should get a 3rd one directly from VW. Maybe. But my 2 sensors act the same, so can 2 sensors fail the same way at the same time?

I think I should check better the trigger wheel. It looked fine, but maybe the angle to look at it was bad enough so I couldn't see deposits on it. I'll have to get that side cover removed, maybe the wheel is loose!! That I did not check.

Anyway, my guess is I have something corrupting the signal. Need to find what.
Frank
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