[Diy_efi] Re: Problem with cam mounted optical trigger sensor andRFI
mark krawczuk
krawczuk
Thu Apr 6 10:35:42 UTC 2006
hi, what about a ceramic or greenncap across the signal ?
mark k
----- Original Message -----
From: "Damian Long" <bigcow_610 at yahoo.com.au>
To: <diy_efi at diy-efi.org>
Sent: Thursday, April 06, 2006 7:06 PM
Subject: [Diy_efi] Re: Problem with cam mounted optical trigger sensor
andRFI
> Thank you to those who have sent some advice.
>
> First I ran better sheilded cable, replaced the condensor and ran a new
> engine earth cable. This seemed to tone down the noise but it was still
> there.
>
> I then replaced the solid core spark leads I was using for some stock
> suppression cable. This made a huge difference and problem seemed to be
> gone. I replaced the standard coil with the CDI ignition. The car started
> for the first time on the CDI ignion but there was intermitted noise on
> the signal causing problems once again.
>
> I reverted back to the coil and thought I'd do some tuning. After a while
> of running everything seemed fine. I was stopping and starting the engine
> as I was mapping. At one stage I went to start the car again and the
> problem was back worse than ever! Now it won't even start as the noise is
> messing the signal badly.
>
> This is a very frustrating problem. Obviously something is amiss and I am
> starting to suspect the grounding system. Perhaps a ground loop? very
> annoying, very random
>
> Damian
>
>
> diy_efi-request at diy-efi.org wrote:
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> Today's Topics:
>
> 1. RE: Swaping 1225550 crossfire with 1227747 (correction)
> (Chuck Kahler)
> 2. Problem with cam mounted optical trigger sensor and RFI
> (Damian Long)
> 3. Re: Problem with cam mounted optical trigger sensor and RFI
> (Torbj?rn Forsman)
> 4. Re: Problem with cam mounted optical trigger sensor and RFI
> (Charles Slack)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Sat, 01 Apr 2006 17:40:07 -0800
> From: "Chuck Kahler"
> Subject: [Diy_efi] RE: Swaping 1225550 crossfire with 1227747
> (correction)
> To:
> Message-ID:
> Content-Type: text/plain; charset="iso-8859-1"
>
>
> Just wanted to let the forum know I finished the ECM swap out and it
> worked
> great, started right up and ran fine.
>
> Thanks for all the help various folks gave me along the way.
>
> Only one question remains; initially when the engine first started up the
> idle was high about 1800 rpm and as the engine warmed up the idle stepped
> down to about 700, which was great. Now the idle stays high at about 1800
> rpm even after the car is driven around. .
>
> Any suggestions as to what could be going on here.
>
> Thanks,
> Chuck
>
>
>
>
> ------------------------------
>
> Message: 2
> Date: Sun, 2 Apr 2006 20:16:33 +1000 (EST)
> From: Damian Long
> Subject: [Diy_efi] Problem with cam mounted optical trigger sensor and
> RFI
> To: diy_efi at diy-efi.org
> Message-ID: <20060402101633.3010.qmail at web50312.mail.yahoo.com>
> Content-Type: text/plain; charset=iso-8859-1
>
> Hello,
>
> I am installing a Walbro TDD ecu. It uses a motronic style 60-2 wheel. I
> have cam mounted this wheel. Basically what I have done is removed the
> standard cam mounted trigger disk (found inside the distributor) and
> replaced it with a custom disk.
> The sensor used to read the disk is a common standard Mitsubishi optical
> sensor that is found in the likes of Hyundai Excels, Nissans and Mazdas. I
> am using a sensor from an Nissan SR20 engine.
> What is happening is that everything works fine from a cold engine. The
> ecu reads the signal perfectly and the engine runs great. As soon as the
> engine gets warm it seems like the sensor (or wires) gets some RF
> interferance from the high tension leads. The rpm reading goes nuts like
> 54000rpm and ecu obviously complains. At first I thought maybe a broken
> sensor as I have seen these have problems before when they get hot but the
> problem seems very dependant on how and where I run the wires to the
> sensor. Also if I connect a high power CDI ignition the problem is 10
> fold. It does it from cold or hot. This leads me to believe it is not a
> broken sensor and the temperature has something to do with letting the RFI
> in.
> Looking at the signal going into the ecu on an oscilliscope there is a
> nice square wave even when the strange RPM begin to happen. I don't
> totally understand why this is. It could be the RFI is causing the circuit
> inside the optical sensor to send false triggers (there is a small
> conditioning circuit inside the optical sensor).
> All help appreciated.
>
> Oh and Matt, if you are reading this. I live right near you. I am in
> Wollongong. I have seen your AFR gauges in a friends car. I like them and
> may buy one.
>
> cheers
> Damian
>
>
> ---------------------------------
> On Yahoo!7
> Messenger: Make free PC-to-PC calls to your friends overseas.
>
> ------------------------------
>
> Message: 3
> Date: Sun, 02 Apr 2006 12:37:21 +0200
> From: Torbj?rn Forsman
> Subject: Re: [Diy_efi] Problem with cam mounted optical trigger sensor
> and RFI
> To: diy_efi at diy-efi.org
> Message-ID: <442FA961.6030708 at gengas.nu>
> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>
> Try using screened wiring between the ECU and the sensor. Ground the
> screen at some suitable ground pin of the ECU (some general signal
> ground, ground for the screened cable to the O2 sensor or something) and
> let the screen be unconnected at the sensor.
>
> Another thing that might be worth trying is to low pass filter the
> signal from the sensor, in case there is some high frequency content
> from the ignition impulses overlaid on it. Probably, there is already
> some sort of filtering in the ECU but you might need a lower cut-off
> frequency.
>
> Best regards
>
> Torbj?rn Forsman
>
> Damian Long wrote:
>> Hello,
>>
>> I am installing a Walbro TDD ecu. It uses a motronic style 60-2 wheel. I
>> have cam mounted this wheel. Basically what I have done is removed the
>> standard cam mounted trigger disk (found inside the distributor) and
>> replaced it with a custom disk.
>> The sensor used to read the disk is a common standard Mitsubishi optical
>> sensor that is found in the likes of Hyundai Excels, Nissans and Mazdas.
>> I am using a sensor from an Nissan SR20 engine.
>> What is happening is that everything works fine from a cold engine. The
>> ecu reads the signal perfectly and the engine runs great. As soon as the
>> engine gets warm it seems like the sensor (or wires) gets some RF
>> interferance from the high tension leads. The rpm reading goes nuts like
>> 54000rpm and ecu obviously complains. At first I thought maybe a broken
>> sensor as I have seen these have problems before when they get hot but
>> the problem seems very dependant on how and where I run the wires to the
>> sensor. Also if I connect a high power CDI ignition the problem is 10
>> fold. It does it from cold or hot. This leads me to believe it is not a
>> broken sensor and the temperature has something to do with letting the
>> RFI in.
>> Looking at the signal going into the ecu on an oscilliscope there is a
>> nice square wave even when the strange RPM begin to happen. I don't
>> totally understand why this is. It could be the RFI is causing the
>> circuit inside the optical sensor to send false triggers (there is a
>> small conditioning circuit inside the optical sensor).
>> All help appreciated.
>>
>> Oh and Matt, if you are reading this. I live right near you. I am in
>> Wollongong. I have seen your AFR gauges in a friends car. I like them and
>> may buy one.
>>
>> cheers
>> Damian
>>
>>
>> ---------------------------------
>> On Yahoo!7
>> Messenger: Make free PC-to-PC calls to your friends overseas.
>> _______________________________________________
>> Diy_efi mailing list
>> Diy_efi at diy-efi.org
>> http://lists.diy-efi.org/mailman/listinfo/diy_efi
>>
>
>
>
> ------------------------------
>
> Message: 4
> Date: Sun, 02 Apr 2006 11:35:16 -0500
> From: Charles Slack
> Subject: Re: [Diy_efi] Problem with cam mounted optical trigger sensor
> and RFI
> To: diy_efi at diy-efi.org
> Message-ID: <442FFD44.2080808 at arlut.utexas.edu>
> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>
> Damian, Looks like you may be having RFI running back through the DC
> supply lines.
> Put a large capacitor say 500 Uf @25 VDC and a small cap ( 0.01 uf @ 25
> VDC) across
> the dc power leads to the CDI ignition module. You can try a 0.01 uf
> @100Vdc as
> a HF bypass across the pick up leads, and across the incoming air temp
> sensor.
> My 2 cents.
> Charlie Slack
> Austin, TX
>
>
>
> Damian Long wrote:
>
>>Hello,
>>
>> I am installing a Walbro TDD ecu. It uses a motronic style 60-2 wheel. I
>> have cam mounted this wheel. Basically what I have done is removed the
>> standard cam mounted trigger disk (found inside the distributor) and
>> replaced it with a custom disk.
>> The sensor used to read the disk is a common standard Mitsubishi optical
>> sensor that is found in the likes of Hyundai Excels, Nissans and Mazdas.
>> I am using a sensor from an Nissan SR20 engine.
>> What is happening is that everything works fine from a cold engine. The
>> ecu reads the signal perfectly and the engine runs great. As soon as the
>> engine gets warm it seems like the sensor (or wires) gets some RF
>> interferance from the high tension leads. The rpm reading goes nuts like
>> 54000rpm and ecu obviously complains. At first I thought maybe a broken
>> sensor as I have seen these have problems before when they get hot but
>> the problem seems very dependant on how and where I run the wires to the
>> sensor. Also if I connect a high power CDI ignition the problem is 10
>> fold. It does it from cold or hot. This leads me to believe it is not a
>> broken sensor and the temperature has something to do with letting the
>> RFI in.
>> Looking at the signal going into the ecu on an oscilliscope there is a
>> nice square wave even when the strange RPM begin to happen. I don't
>> totally understand why this is. It could be the RFI is causing the
>> circuit inside the optical sensor to send false triggers (there is a
>> small conditioning circuit inside the optical sensor).
>> All help appreciated.
>>
>> Oh and Matt, if you are reading this. I live right near you. I am in
>> Wollongong. I have seen your AFR gauges in a friends car. I like them and
>> may buy one.
>>
>> cheers
>> Damian
>>
>>
>>---------------------------------
>>On Yahoo!7
>> Messenger: Make free PC-to-PC calls to your friends overseas.
>>_______________________________________________
>>Diy_efi mailing list
>>Diy_efi at diy-efi.org
>>http://lists.diy-efi.org/mailman/listinfo/diy_efi
>>
>>
>>
>
>
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