ECMlink Scaring the crap out of myself(knock)

[SasaniFab]

So my customer came by today to turn up the boost as we had the car dialed in... so we thought. Took the car out for a pull and it hesitated at wot almost like ignition issues, very choppy , in and out. Took the car home and took the plug out and the ground electrode was melted back a bit which obviously scared the shit out of me. This didnt make any sense to me as the car had no knock and the afrs were solid. Come to find out the previous owner turned the knock sensor off until 7500 .... my mistake for not noticing. I compression tested the car 180 dead on all 4 with 0 smoke and 190 temps all day.... so relieved. I installed new plugs and took the car out with the knock sensor activated.... car was registering knock up the ass at part throttle and wot. Timing and fuel made no difference. Come to find out the previous owner blew up their engine under similar circumstances but instead of fixing the issue they turned of the knock sensor and turned the boost up. Same injectors were used on the same cylinders from that engine on this one. The injectors were flow tested and everything looked normal. The injectors in question are pte 1200 that are over 10 yeats old. Based on the above symptoms im leaning towards a bad injector in number 3. The other cylinders looked great. What do you guys think?

 

[motomattx]

What condition is the knock sensor in? it could be bad and oversensitive and its reading too much knock at part throttle but you have real knock at high load, this would explain the fuel and timing not having any effect on knock, what engine management is in the car?

 

[stillrunning]

Try to get higher octane fuel in there and see if the knock goes down, at least this would tell you you may be octane limited and the knock sensor is probably ok.
You could also pull the timing until you get no knock and work it from there, this would also tell you the knock sensor is ok if you can get the knock to stop with reduced timing.
I've never had allot of luck reducing knock by just afr alone at WOT.
To me it's safer to just reduce the timing and accept what the engine is happy with rather than try to ride the absolute edge, that is unless it's a track car.

 

[ThunderChild]

To weigh in for a similar scenario: my car has had knock all over the place since I finished building it. Originally knock would register a solid -12* retard constantly, anywhere but idle really. Eventually I tried rewiring the sensor a couple times to no avail, then tried tieing both wires together as I'd seen in another thread (can't find it atm, and it sounded like it wouldn't work but I was at my wit's end).
Lo-and-behold, I lost most of my tip in knock was gone and was only getting counts in the mid/upper load/RPM ranges, fluctuating numbers properly, grading etc. like it seemed natural compare to other ppls logs.
Then I tried adjusting timing, fuel, running some 110 octane in it...knock never changed from most recent style. Less timing, more fuel, more octane, knock the same.

Currently I have the safest tune I can figure on it and have my knock turned off, and as far as I can tell it runs great as is up to 17psi on the 14b. Plugs and pistons look great, exhaust is slightly rich looking (my preference and how it's tuned currently), so I'm attributing it to the stock system not able to use the factory sensor in the ranges a modified motor needs.

I am aware this is not a good idea, and am currently looking into a J&S aftermarket knock sensing system like @turboglenn is/was using (where is he anyway?).

I've emailed with John @ J&S and he has a couple systems he recommended. Granted, they're not what I'd consider "cheap", but if it can correctly detect knock and adjust timing like John says, it'd be well worth it.

Sorry to thread jack @amsrn13 , just figured I'd weigh in since the subject was out there again.

 

[motomattx]

The 2g sensor is passive, just unplug it if you dont want to use it. If your running gasoline even on a stock tune, you want knock control, on alcohol you dont really need it so much since the tuning strategies are different between gasoline and alcohol, as you tune for mbt on alcohol rather than looking for maximum power with minimum knock on gasoline.

 

[motomattx]

To weigh in for a similar scenario: my car has had knock all over the place since I finished building it. Originally knock would register a solid -12* retard constantly, anywhere but idle really. Eventually I tried rewiring the sensor a couple times to no avail, then tried tieing both wires together as I'd seen in another thread (can't find it atm, and it sounded like it wouldn't work but I was at my wit's end).
Lo-and-behold, I lost most of my tip in knock was gone and was only getting counts in the mid/upper load/RPM ranges, fluctuating numbers properly, grading etc. like it seemed natural compare to other ppls logs.
Then I tried adjusting timing, fuel, running some 110 octane in it...knock never changed from most recent style. Less timing, more fuel, more octane, knock the same.

Currently I have the safest tune I can figure on it and have my knock turned off, and as far as I can tell it runs great as is up to 17psi on the 14b. Plugs and pistons look great, exhaust is slightly rich looking (my preference and how it's tuned currently), so I'm attributing it to the stock system not able to use the factory sensor in the ranges a modified motor needs.

I am aware this is not a good idea, and am currently looking into a J&S aftermarket knock sensing system like @turboglenn is/was using (where is he anyway?).

I've emailed with John @ J&S and he has a couple systems he recommended. Granted, they're not what I'd consider "cheap", but if it can correctly detect knock and adjust timing like John says, it'd be well worth it.

Sorry to thread jack @amsrn13 , just figured I'd weigh in since the subject was out there again.

One of the better ones is the Knock Block from Link Ecu.

 

[SasaniFab]

Its ecm link, i never experienced this much knock on any setup. Like i said the same issue occured on the same car with a diff motor on number 3, the car runs great otherwise. This isnt phantom knock, its real.... based on how bad the plug looked. That cylinder isnt getting fueled properly......Im having him buy new injectors and well go from there. 20 psi on a fp red shouldnt be knocking. Esp with no timing and 10.8 afrs.... this is where an egt or wide band in each runner would be awesome.

 

[ThunderChild]

One of the better ones is the Knock Block from Link Ecu.

Seems pretty good, but (I could be wrong or under-educated on this particular unit) it doesn't seem to have quite the feature list that the j&s does, unless you're also running a link ecu. The price is also considerably higher, but it may be much better than my limited research revealed.

For the cost it's almost tempting to go with a different EMS that has better knock control, but ecmlink is soooo good for everything else.

 

[SasaniFab]

Seems pretty good, but (I could be wrong or under-educated on this particular unit) it doesn't seem to have quite the feature list that the j&s does, unless you're also running a link ecu. The price is also considerably higher, but it may be much better than my limited research revealed.

For the cost it's almost tempting to go with a different EMS that has better knock control, but ecmlink is soooo good for everything else.

something tells me your issues are wiring related. What shape is your harness in?

 

[ThunderChild]

I wondered the same thing, and aside from a couple clips (TPS and CPS) with cracked corners, it's in very good shape for it's age. I tested and traced the knock circuit all the way into the car, and neither found nor tested any issues. Even after running all new shielded wire, extra grounds etc. I couldn't get the stock setup to work.
I also tracked down any loose stuff I could and eliminated any wierd resonance stuff I could think of (heat shields, exhaust clearance, interior panels...).
Trust me, I spent a solid couple weeks trying to sort it out, researching, and having my buddy who's more familiar with ecmlink than myself come look at things, and he couldn't understand why it was registering knock either.

We took timing all the way down to negative, as well as added fuel till it was running stupid rich, swung the other way just to see if it was rich knock... Nothing changed, still registered and climbed the same any time we put throttle into it under load, no matter how I had it wired.

It also doesn't make sense, since my IATs are only 15-25* over ambient after several highway pulls (large w2a intercooler setup) and ~5-10* steady cruise or before any pulls.

I finally just tuned it conservative on timing and 11:1 under load, and it runs very good like so, but I don't like not knowing IF it's knocking. I don't drive it a ton right now and until I can get a solid knock sense system that makes sense I don't plan to put alot of miles on it.

 

[1990TSIAWDTALON]

@amsrn13, I had a similar issue and the same dam setting in my link computer that I bought on here a while back. I was showing NO knock and was quite happy, but something made me look at the sensor settings and low and behold, whoever had the ECU before me had set it to come on at 7500 and go off at 9400
I reset the sensor to come on at 3000 and started logging the knock that was now showing. This was in my 1gb auto car. I just couldn't believe that the motor didn't even like 4* so I bumped the setting back up and WHAT A STUPID MOVE. I burned the ground strap, porcelain and melted a small portion of #4 piston, right where the valve relief is on the piston. TERRIBLE. That is why I am rebuilding her now. I was even seeing knock at 0*. Couldn't find anything loose, new sensor.....I will always put trust in my sensor now, to pull that timing so it doesn't kill the motor.
Just saying that I had timing issues also, but they were real, so be careful.

 

[ThunderChild]

@1990TSIAWDTALON that strange, what turbo setup was that Marty? I have a hard time believing I can't get timing up anymore than I have mine rn, and I'm just barely over stock stuff. In fact most of my setup should allow for a more aggressive tune, if anything.

I went -8* and still didn't see any knock change, and the car ran like poo. I checked plugs and chambers/pistons drive before last and everything looks great, so I'm pretty sure my tune is ok for the moment. I just wish there was more adjustment to account for changes in link for the knock function, like using a wideband donut sensor and having a calibration setting. Idk enough about knock sensors to get into detail, but I assume it's possible to set up and add in. Just depends on how much it costs really, I know I'd pay for a knock detection upgrade through link as long as it worked properly.

 

[rEclipserGST]

So my customer came by today to turn up the boost as we had the car dialed in... so we thought. Took the car out for a pull and it hesitated at wot almost like ignition issues, very choppy , in and out. Took the car home and took the plug out and the ground electrode was melted back a bit which obviously scared the sh** out of me. This didnt make any sense to me as the car had no knock and the afrs were solid. Come to find out the previous owner turned the knock sensor off until 7500 .... my mistake for not noticing. I compression tested the car 180 dead on all 4 with 0 smoke and 190 temps all day.... so relieved. I installed new plugs and took the car out with the knock sensor activated.... car was registering knock up the ass at part throttle and wot. Timing and fuel made no difference. Come to find out the previous owner blew up their engine under similar circumstances but instead of fixing the issue they turned of the knock sensor and turned the boost up. Same injectors were used on the same cylinders from that engine on this one. The injectors were flow tested and everything looked normal. The injectors in question are pte 1200 that are over 10 yeats old. Based on the above symptoms im leaning towards a bad injector in number 3. The other cylinders looked great. What do you guys think?

Why not just swap the injector into another cylinder? Why buy new injectors before swapping it? That would've been my first move.

 

[1990TSIAWDTALON]

@ThunderChild, it was my 92 6/4 auto. 180k, 16g, SMIC, SD with FIC 1120s. Stock auto cams at 23lbs boost. Going to a FMIC, Kelford 264s and my other HX40 and A NEW KNOCK SENSOR

 

[SasaniFab]

@amsrn13, I had a similar issue and the same dam setting in my link computer that I bought on here a while back. I was showing NO knock and was quite happy, but something made me look at the sensor settings and low and behold, whoever had the ECU before me had set it to come on at 7500 and go off at 9400
I reset the sensor to come on at 3000 and started logging the knock that was now showing. This was in my 1gb auto car. I just couldn't believe that the motor didn't even like 4* so I bumped the setting back up and WHAT A STUPID MOVE. I burned the ground strap, porcelain and melted a small portion of #4 piston, right where the valve relief is on the piston. TERRIBLE. That is why I am rebuilding her now. I was even seeing knock at 0*. Couldn't find anything loose, new sensor.....I will always put trust in my sensor now, to pull that timing so it doesn't kill the motor.
Just saying that I had timing issues also, but they were real, so be careful.

What was the cause of the knock? I'm hoping the forged Pistons weren't damaged to much in his motor. The compression looks great so I think we escaped unharmed. Those injections were used In the engine that went last time. I want them out.

 

[We're on Boost]

@amsrn13 whoever had the ECU before me had set it to come on at 7500 and go off at 9400

Where was yours set to turn off at 9400? I don't see a place for that. I only see the turn on. I'd like to check this on mine if I could find it.

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[SasaniFab]

Why not just swap the injector into another cylinder? Why buy new injectors before swapping it? That would've been my first move.

I want anything and everything from that previous motor off the engine

 

[SasaniFab]

Where was yours set to turn off at 9400? I don't see a place for that. I only see the turn on. I'd like to check this on mine if I could find it.

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He just saying that when set at 7500 it's basically off

 

[We're on Boost]

He just saying that when set at 7500 it's basically off

The way the post reads, it sounds like it was set to be:
Off from 0 to 7,500 RPM
On from 7,500 RPM to 9,400 RPM
Off at anything above 9,400 RPM

If this is for real that there is a 2nd setting where you can set another RPM value, I want to know about it so I can check it.

 

[ThunderChild]

I want anything and everything from that previous motor off the engine

That's understandable, it's also a quicker turnover typically than sending injectors to be cleaned/tested if it's something that you want or need to drive in the mean time. Being that's already been done, have you checked to make sure the engine and chassis have good grounding points? The situation makes me think that, maybe in conjunction with a lean mixture, the grounds aren't great.

Was the injectors flow test good? And was it only that one plug that was jacked up?

I'd be interested to see what the old injectors do in a test for confirmation of suspicion.

@1990TSIAWDTALON yea that seems to be a pretty normal setup, maybe what I'd call "hotter" than mine. I believe my profile is current, but the cliff notes are: refreshed stock 6 bolt, Hyundai "small chamber/big port" head, cyclone intake w/ T25 actuator, stock 92 5speed cams, n/a TB, 11x13x4.5 w2a I/C, 3" gm MAF, ported 2g exh. Mani, ported 8cm eBay turbine housing with rebuilt 14b, ported compressor outlet, ported PR o2, 3" turbo back, cleaned/tested pte 880cc inj.

The w2a has all -16an lines, jabsco pump, 24x8x2 dual pass h/e, 4.5 gallon reservoir, dual 10" puller fans.

 

[SasaniFab]

That's understandable, it's also a quicker turnover typically than sending injectors to be cleaned/tested if it's something that you want or need to drive in the mean time. Being that's already been done, have you checked to make sure the engine and chassis have good grounding points? The situation makes me think that, maybe in conjunction with a lean mixture, the grounds aren't great.

Was the injectors flow test good? And was it only that one plug that was jacked up?

I'd be interested to see what the old injectors do in a test for confirmation of suspicion.

@1990TSIAWDTALON yea that seems to be a pretty normal setup, maybe what I'd call "hotter" than mine. I believe my profile is current, but the cliff notes are: refreshed stock 6 bolt, Hyundai "small chamber/big port" head, cyclone intake w/ T25 actuator, stock 92 5speed cams, n/a TB, 11x13x4.5 w2a I/C, 3" gm MAF, ported 2g exh. Mani, ported 8cm eBay turbine housing with rebuilt 14b, ported compressor outlet, ported PR o2, 3" turbo back, cleaned/tested pte 880cc inj.

The w2a has all -16an lines, jabsco pump, 24x8x2 dual pass h/e, 4.5 gallon reservoir, dual 10" puller fans.

This is my rational. Let’s take the cars past history out of the equation, that being number 3 cylinder running lean on the previous engine. Setting up a car on ecmlink is basically fool proof. Get yourself some injectors, wideband and go to town. All you need to do is get your global set Within reason and modify your timing. The software even calculates the numbers for you. This will get somewhat close to a good air/fuel mixture at wot. Then it’s just a matter of dialing it in. Every car I’ve tuned with a fp turbo on 93 had no issues with knock on 93 up and around 25 psi. This car should not be knocking at 20psi on 93 with a 10.8 afr with basically no timing. The plugs tell the entire picture, they all look great except for 3.... even after changing the plug and taking a ride , it looked white after a light rip. Im thinking ecu or injectors..... what else could it be? Resistor pack? Having a good afr can be misleading ...... it doesnt give you a clear picture cylinder to cylinder

 

[ThunderChild]

This is my rational. Let’s take the cars past history out of the equation, that being number 3 cylinder running lean on the previous engine. Setting up a car on ecmlink is basically fool proof. Get yourself some injectors, wideband and go to town. All you need to do is get your global set Within reason and modify your timing. The software even calculates the numbers for you. This will get somewhat close to a good air/fuel mixture at wot. Then it’s just a matter of dialing it in. Every car I’ve tuned with a fp turbo on 93 had no issues with knock on 93 up and around 25 psi. This car should not be knocking at 20psi on 93 with a 10.8 afr with basically no timing. The plugs tell the entire picture, they all look great except for 3.... even after changing the plug and taking a ride , it looked white after a light rip. Im thinking ecu or injectors..... what else could it be? Resistor pack? Having a good afr can be misleading ...... it doesnt give you a clear picture cylinder to cylinder

True, something individual is happening there, and being that cylinder 2 isn't also giving the same plug reading, but your afr is good means: injector, wire or plug. I assume the coil can't be it, since they waste fire together. I also don't think it's the ECU since they pair fire as well (don't recall if there's individual injector driver's or 1 per pair), but it could be the individual wire for that injector?

Switch the injector around and see if it follows it, might just be clogged up partially making it run lean, and the other 3 are compensating giving the stable AFR. If it stays, test wire continuity and look for the usual.

 

[SasaniFab]

True, something individual is happening there, and being that cylinder 2 isn't also giving the same plug reading, but your afr is good means: injector, wire or plug. I assume the coil can't be it, since they waste fire together. I also don't think it's the ECU since they pair fire as well (don't recall if there's individual injector driver's or 1 per pair), but it could be the individual wire for that injector?

Switch the injector around and see if it follows it, might just be clogged up partially making it run lean, and the other 3 are compensating giving the stable AFR. If it stays, test wire continuity and look for the usual.

My customer is buying new pte 1200 injectors as the 1650s arent in the budget. He is installing a new knock sensor that he had already. Im going to check the wiring at the ecu to make sure the wires arent loose. Should be ready to try again early next week.

 

[SasaniFab]

True, something individual is happening there, and being that cylinder 2 isn't also giving the same plug reading, but your afr is good means: injector, wire or plug. I assume the coil can't be it, since they waste fire together. I also don't think it's the ECU since they pair fire as well (don't recall if there's individual injector driver's or 1 per pair), but it could be the individual wire for that injector?

Switch the injector around and see if it follows it, might just be clogged up partially making it run lean, and the other 3 are compensating giving the stable AFR. If it stays, test wire continuity and look for the usual.

My intuition was correct. After replacing the injectors, the car no longer produces knock and pulls hard without hesitation. Im extremely happy this all worked out. The car is still on 93 but I’ve convinced my customer to run a mix with some race gas for extra protection. More to come boys