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 Post subject: RobTune: knock light flickering
PostPosted: Tue Nov 25, 2014 5:59 pm 
Fourth Gear
Joined: Tue Jul 31, 2012 10:32 pm
Posts: 1229
Location: Portland, Oregon.
I figured I would make a thread because I'm unable to find any substantial information about the knock light feature of the RobTune.

While driving if I really get on it in some gears, around 3800 RPMs the knock light will flicker or flash, and sometimes it will also flash if I'm in 4/5th gear and gas it a little bit.

Is this cause for concern? Is my engine actually "knocking" and on it's last legs? Or is a bit of knocking normal? I'm just curious on this because I'm not really sure exactly what is happening or what the knock sensor is reading.

My AFRs are in the 11's at WOT

Mods:
RobTune
550's
16G TD05
Large FMIC
3" turbo back
Manual boost controller at 15ish

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 Post subject: Re: RobTune: knock light flickering
PostPosted: Tue Nov 25, 2014 6:34 pm 
Fourth Gear
Joined: Sun Jun 10, 2007 4:35 am
Posts: 1746
Location: Arkansas
Mine flicked on long 3/4 pulls too. My engine seemed to be in good shape, and had a fresh tune-up when I did my swap. Even compression on thehigh end of the spec and everything.

I'm wondering if its just normal, and our concern is the reason no such light has ever been offered by an OEM.

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 Post subject: Re: RobTune: knock light flickering
PostPosted: Tue Nov 25, 2014 10:24 pm 
Fourth Gear
Joined: Tue Jul 31, 2012 10:32 pm
Posts: 1229
Location: Portland, Oregon.
Yeah, I'm hoping rob can chime in or someone who knows more. I'm hoping that it's a normal thing, but I have read people saying the knock light never comes on, besides maybe lugging it up a hill in 5th

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 Post subject: Re: RobTune: knock light flickering
PostPosted: Wed Nov 26, 2014 11:42 pm 
Fourth Gear
Joined: Tue Jul 31, 2012 10:32 pm
Posts: 1229
Location: Portland, Oregon.
Does the light indicate detonation or like an engine knock? Like a rod?

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 Post subject: Re: RobTune: knock light flickering
PostPosted: Thu Nov 27, 2014 2:04 am 
Fourth Gear
Joined: Sun Jun 10, 2007 4:35 am
Posts: 1746
Location: Arkansas
It indicates detonation knock, its just a visual representation of the stock knock sensor working. You'd hear rod knock.

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 Post subject: Re: RobTune: knock light flickering
PostPosted: Thu Nov 27, 2014 4:18 am 
Fourth Gear
Joined: Tue Jul 31, 2012 10:32 pm
Posts: 1229
Location: Portland, Oregon.
So it flickering is normal?

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 Post subject: Re: RobTune: knock light flickering
PostPosted: Tue Dec 02, 2014 5:23 am 
Fourth Gear
Joined: Tue Jul 31, 2012 10:32 pm
Posts: 1229
Location: Portland, Oregon.
Now my clutch is in and I have been able to feel the car better, sometimes when I hit the gas real hard for the first time during the drive (car is hot) the car starts stuttering and popping and the cel is flickering. I just did a 3rd gear pull and the light was flickering and cut out, almost identical to fuel cut. Boost gauge shows I peaked at 18psi so idk what's going on. Am I detonating?

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 Post subject: Re: RobTune: knock light flickering
PostPosted: Wed Dec 03, 2014 5:46 am 
Fifth Gear
Joined: Mon Nov 06, 2006 3:41 am
Posts: 8352
Location: Tenino, WA
Can you get a video? Mine flickers when there's codes. I'd like to see if yours looks like this or looks like when I actually have knock or the sensor at least thinks there's knock (could be something else clunking).

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 Post subject: Re: RobTune: knock light flickering
PostPosted: Wed Dec 03, 2014 7:39 am 
Fourth Gear
Joined: Tue Jul 31, 2012 10:32 pm
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Location: Portland, Oregon.
Yeah I'll take one on my drive home tonight.

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 Post subject: Re: RobTune: knock light flickering
PostPosted: Wed Dec 03, 2014 8:36 am 
Fourth Gear
Joined: Tue Jul 31, 2012 10:32 pm
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Location: Portland, Oregon.
Here's a vid, 4th gear.


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 Post subject: RobTune: knock light flickering
PostPosted: Wed Dec 03, 2014 8:37 am 
Fourth Gear
Joined: Tue Jul 31, 2012 10:32 pm
Posts: 1229
Location: Portland, Oregon.
I just watched my AFR and I was high 12 and 13's..... So I may be running lean. I'm not really sure where to check for things that make me run lean...

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 Post subject: Re: RobTune: knock light flickering
PostPosted: Wed Dec 03, 2014 10:47 am 
quasi-mod-o
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Any fuel leaks at the injectors, boost leaks

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 Post subject: Re: RobTune: knock light flickering
PostPosted: Wed Dec 03, 2014 10:49 am 
quasi-mod-o
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Injectors clogged, bad 02 sensor?

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90 LS Spec rio red sold
91 SS rio red R.I.P
90 Mazda Miata
2005 GT SWP

92ss satinsvoice wrote:
LOL! that block was like F*** THIS! IM OUT!

mike-tracy wrote:
Word. I'd love to get my hands on one of those trannies, but I just can't stomach the cost


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 Post subject: Re: RobTune: knock light flickering
PostPosted: Wed Dec 03, 2014 10:51 am 
quasi-mod-o
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oh, also spark plugs good.

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Tony
90 LS Spec rio red sold
91 SS rio red R.I.P
90 Mazda Miata
2005 GT SWP

92ss satinsvoice wrote:
LOL! that block was like F*** THIS! IM OUT!

mike-tracy wrote:
Word. I'd love to get my hands on one of those trannies, but I just can't stomach the cost


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 Post subject: Re: RobTune: knock light flickering
PostPosted: Wed Dec 03, 2014 8:43 pm 
Fourth Gear
Joined: Tue Jul 31, 2012 10:32 pm
Posts: 1229
Location: Portland, Oregon.
No fuel leaks that I can see, o2 sensor seems fine I think, injectors haven't been flow tested, and spark plugs are brand new.

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 Post subject: Re: RobTune: knock light flickering
PostPosted: Thu Dec 04, 2014 8:35 am 
Fourth Gear
Joined: Tue Jul 31, 2012 10:32 pm
Posts: 1229
Location: Portland, Oregon.
Fuel pressure regulator wasn't hooked up, the vac line on the intake manifold was disconnected. Since plugging that line back in, it has been good in the AFR's. But still the light is flickering.

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 Post subject: Re: RobTune: knock light flickering
PostPosted: Sun Dec 07, 2014 9:14 pm 
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I would want Rob to confirm, but I suspect the light is like others have mentioned a visual representation of what the knock sensor is reading. There is "general" engine noise at different frequencies as the engine goes through the rpm range. The knock sensor may be picking up noise that is showing up with the light, but it may not be actual knock.

My Link ECU does this very same thing. It will detect engine noise, but it's really not detonation. If the ECU isn't pulling timing I wouldn't be concerned.

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 Post subject: Re: RobTune: knock light flickering
PostPosted: Mon Dec 08, 2014 8:45 am 
Fourth Gear
Joined: Tue Jul 31, 2012 10:32 pm
Posts: 1229
Location: Portland, Oregon.
My AFRs are in the 10's under WOT, definitely what I like to see.

The light still flashes here and there with the regular AFR's, so I'm just going off that it's a visual representation of the knock sensor. The car pulls so good, I love it.

What had me wondering is that people said they never see the knock light with their RobTune, so I was hoping that it didn't mean my motor was making extra noise. Maybe Rob will chime in.

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 Post subject: Re: RobTune: knock light flickering
PostPosted: Mon Dec 08, 2014 9:10 am 
Fourth Gear
Joined: Sun Jun 10, 2007 4:35 am
Posts: 1746
Location: Arkansas
Have you e-mailed Rob about it? I'm curious too, but don't want to go bombarding him with the same question.

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 Post subject: Re: RobTune: knock light flickering
PostPosted: Fri Dec 12, 2014 8:02 am 
Second Gear
Joined: Mon Oct 25, 2010 6:28 pm
Posts: 367
Location: Vancouver, B.C. Canada.
Rarely on here anymore since my shit hasn't blown up lately lol.

But my setup basically sounds exactly the same except 440 injectors. Brand new Knock Sensor.

Leak down test was solid on the motor . When I'm WOT, it does flicker a bit, AFR's are are 10.9. Brand new innovative LC-1 & Bosch O2 sensor . Checked my FPR line, all good. Brand new Silicone line.

11's still pretty rich, I wouldn't think there would be a problem ! So the flickering went away with the line re-connected and it running at 10 ?

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 Post subject: Re: RobTune: knock light flickering
PostPosted: Fri Dec 12, 2014 6:27 pm 
Fourth Gear
Joined: Tue Jul 31, 2012 10:32 pm
Posts: 1229
Location: Portland, Oregon.
I'm running like 10.5 ish and yeah my knock light flickers quite a bit in throttle actually. Even after I fixed the lean issue. But the motor sounds healthy!

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 Post subject: Re: RobTune: knock light flickering
PostPosted: Mon Dec 15, 2014 12:35 am 
Fourth Gear
Joined: Tue Jul 31, 2012 10:32 pm
Posts: 1229
Location: Portland, Oregon.
Hope this is normal? And rob might chime in. New plugs. V power gapped to .028

Peak boost was 18 on this pull.


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 Post subject: Re: RobTune: knock light flickering
PostPosted: Mon Dec 15, 2014 5:21 am 
Fifth Gear
Joined: Mon Nov 06, 2006 3:41 am
Posts: 8352
Location: Tenino, WA
Hmm pretty difficult to see it in that video. There's a lot of glare from the sun. Difficult to say if that looks like knock light or CEL.

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 Post subject: Re: RobTune: knock light flickering
PostPosted: Mon Dec 15, 2014 10:38 am 
Fourth Gear
Joined: Tue Jul 31, 2012 10:32 pm
Posts: 1229
Location: Portland, Oregon.
I'll try to take one at night. Didn't realize the glare was right over it -_-

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 Post subject: RobTune: knock light flickering
PostPosted: Fri Dec 19, 2014 10:24 am 
Fourth Gear
Joined: Tue Jul 31, 2012 10:32 pm
Posts: 1229
Location: Portland, Oregon.
What would pulling timing feel like?

Randomly the car will hesitate and buck when I get on the gas.. It went away for awhile but did it a few days ago, and then today I was pinned in 4th gear and it hit a wall like fuel cut. Exactly like fuel cut, the car just cut out. I peaked at 19psi. I'm wondering if that was like a timing cut? I noticed the light flickering a little.

I'm gonna replace the knock sensor, maybe it's bad and picking up more frequency than it should? The motor seems healthy. Plus are brand new v power gapped to .028 and the car usually runs great. Just every now and then has a bucking problem. Seems like it happens when it's raining.. Might be a coincidence.

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