led knock light [Merged 2-8]

[97EclipseGSX]

Has anyone done this? I've got everything ready to hook up just am a little scared about messing my ecu up. Anyone have any problems or suggestions?

Thanks
Pat

 

[eric62810]

i was just wondering if there is a way to wire a knock light in my car its a n/a with turbo 2.0 and it doesnt have one if there is could someone post the link for a wireing diagram fo me it would b much appreciated thanks eric

 

[syrushcw]

I would just hook up a light then find the sensor wire on the sensor and splice into that or find it at the ECU connector level to trip the light when ever it knocks.

 

[eric62810]

so run a wire from the lead wire of the sensor to a light in the car and ground it to chasis???

 

[mitch26753]

i'm not quite sure if what he is saying is right. Only options i know for this are knock light kits and things like dsmlink turn your check engine light into a knock light. I wouldn't want to just splice into that and risk gettting wrong readings.

 

[eric62810]

thats what im worried about but the wireng is akredy spliced into was riped of when pulling motor outa old car b4 i got i just wanna monitor knock i dont think i can get dsmlink my car isnt obd2 i dont think its a 93 and i was under the impression that 95 and later was obd2 cars had a flash at speed shop to boost up to 16 and to get rid of the conservitive mixture the car had most time i just run stock levels with boost also i dont wanna use the check engine light id rather know when somthin throws a code so as i can fix the problem so i was wantin to use a led put in dash cluster

 

[absolute_DSM]

"LED knock lights" are as useless as a narrowband O2 gauge.

 

[eric62810]

so what do you suggest i don't wanna buy one when if can make it

 

[talon187]

get dsm link for a 1g

 

[BoostedTalonTS]

i'm not quite sure if what he is saying is right. Only options i know for this are knock light kits and things like dsmlink turn your check engine light into a knock light. I wouldn't want to just splice into that and risk gettting wrong readings.

TECHNICALLY, that is right for any OEM Turbo 1g... The LED / Knock mod has been around for a while now. -It's basically an LED that indicates whenever the OEM ECU it attempting to limit boost as a result of knock. In order to implement the LED, it needs to be integrated into the OEM BCS (boost control solenoid). This method isn't very accurate as it's only an indication that the ECU is in panic mode and is attempting to pull boost... It CANNOT be interpreted as raw knock though.

Being that (according to your profile) that you added a turbo to a naturally aspirated 1G, the BCS is not there from the factory thus making it impossible to add the LED / Knock mod as your ECU doesn't even know and/or care about knock as it doesn't even have any way of monitoring it (no knock sensor either).

Just for reference, the OEM Turbo LED / Knock mod can be seen here:

http://www.vfaq.com/mods/wayback/ledmod_files/howto.htm

BTW, DSMLink is available for OBD1 DSMs, although you would need to find an OEM Turbo EPROM ECU, buy the DSMLink, AND rewire your non-existing knock sensor wires in order to fully utilize the DSMLink's CEL knock indicator... It might be more cost effective to look into a stand-alone knock box.

Good Luck

 

[absolute_DSM]

You dont need one.

 

[cbrfrenzie]

The knock sensor outputs different amplitudes depending on the severity of knock, and engine noise. You will need a biased comparator circuit with the biasing being a linear range of voltages based on RPM. This is because typically the amplitude of the knock sensor increases with RPM as well. The output of your comparator circuit will then feed a transistor that will switch the voltage to an LED.

Like absolute_DSM said previously: " "LED knock lights" are as useless as a narrowband O2 gauge".

Without the proper biasing transfer function and some sort of RPM decoder, unless you're an electronics guru, chances are 99.9% of people still won't get the circuit right for a LED output that actually means something.

To make a long story short, get a socketed EProm and buy a chip that turns the stock boost gauge into a knock indicator, or the check engine light, as mentioned above. That way, the stock ECU does all the signal conditioning for you and you can be sure what you're seeing is actually knock.

 

[eric62810]

no no didnt put a turbo on a na motor its a turbo motor in a na car wireing and ecu also so it should know when theres knock also the wires are there for the knock sensor they were just ripped outa the plug when the ppl took out the motor took a plug of a turbo car and wired it into the harness sorry if my profile is misleading i will fix soon as possible so i should b able to wire from the bcs

 

[BoostedTalonTS]

hmm... figured that'd be the case with the "High Compression Pistons"


Do you know if you got an EPROM ECU in with the whole swap?

 

[cbrfrenzie]

If you wire an LED from the BCS you'll more then likely get an LED that "appears" to be on all the time, as the BCS oscillates at about 10Hz - 30 Hz, depending on the ECU. The ECU merely varies the duty cycle of that pulse to regulate boost.
I'm not sure thats what you're looking for.

If you really wanted to do it, you could find where the conditioned output of the knock chip on ECU is, and solder a voltage follower op-amp circuit on it so that it draws almost zero current (so that you don't skew the signal for the ECU to interpret) then you're transistor, resistor and a wire leading out of the ECU to your LED.

But still, that takes some work and some good ol' fashioned "know how".

 

[eric62810]

i have no clue is there a way to check??

 

[BoostedTalonTS]

i have no clue is there a way to check??

Remove the radio and look at the ECU part number tag... If it has an "E" on it then you SHOULD have an EPROM ECU. -That's a good thing if you are leaning towards getting a DSMLink down the road... It will need to be socketed in order for the DSMLink to be installed though.

If I were you, I'd pull the ECU anyways and inspect it for leaking caps... That way you will know for sure if it has an EPROM board in it. A good write-up on replacing the caps is here:

http://www.vfaq.com/mods/wayback/caps.htm

 

[eric62810]

ill check that out in a few and let you know so there is dsmlink for a 1st gen ive never even tried to tune on a car so i ask how user friendly is it i can build motors all day long and fab parts up that look good as store bought parts (very mechanical) but want some way to get full potential of what i put on the car witch is why i was curious (i built my own exhaust and intake along with i/c pipes also working on o2 housing with 3 in d/p and a cat delete pipe) also if there is a knock light output on the ecm cant i just run from it no factory boost gauge on the car but is a mechanical one along with a/f ratio egt and oil pressure