ECM tach output for 93's
Thread Starter
Le Mans Master
Joined: Feb 1999
Posts: 9,959
Likes: 40
From: South Carolina
St. Jude Donor '03 & '05
ECM tach output for 93's
I am looking in the GM service manual and cant seem to find the tach output. Does anyone know where it is? There has to be one. I am trying to hook up my shift light, which is in another thread, but any assistance would be appreciated.
Ia m useing a DELTEQ, and have emailed Pete and MSD wanting to know where to hook up, as it doesnt work on the tach output of the DELTEQ which could be a square wave to sine wave issue for all I know.
Ia m useing a DELTEQ, and have emailed Pete and MSD wanting to know where to hook up, as it doesnt work on the tach output of the DELTEQ which could be a square wave to sine wave issue for all I know.
Safety Car
Joined: Dec 2002
Posts: 3,655
Likes: 24
From: Charleston SC
Steve,
I found the F-body 93 ECM pin out and just don't see it
http://www.chevythunder.com/myweb/19...tic_page_1.htm
I found the F-body 93 ECM pin out and just don't see it
http://www.chevythunder.com/myweb/19...tic_page_1.htm
Race Director
Joined: Aug 2003
Posts: 13,421
Likes: 8
From: Lake Mary Florida
Originally Posted by steve40th
Thanks
Look at pages 8A-44-6 and 8A-20-4. I'm not certain where to find the output, but there's an input to the ETBCM listed there. The tach itself receives it's info directly from the tach filter. One of it's white wires is split where one side goes to the tach itself and the other side goes to the ETBCM (wire is like 6' long). Black wire with ground connector on it goes to the engine right side (passenger) head. There is a second white wire coming out of the tach filter and goes on to the gray connector half of the coil connector (its black and gray two halves).
I have a couple pictures but don't think they will with what your looking for.
If you can get Tom Piper's attention, he is the real electronic brain. He doesn't have PM enabled and lives in the Tallahassee area.
Thread Starter
Le Mans Master
Joined: Feb 1999
Posts: 9,959
Likes: 40
From: South Carolina
St. Jude Donor '03 & '05
Originally Posted by 93JetJocky
Look at pages 8A-44-6 and 8A-20-4. I'm not certain where to find the output, but there's an input to the ETBCM listed there. The tach itself receives it's info directly from the tach filter. One of it's white wires is split where one side goes to the tach itself and the other side goes to the ETBCM (wire is like 6' long). Black wire with ground connector on it goes to the engine right side (passenger) head. There is a second white wire coming out of the tach filter and goes on to the gray connector half of the coil connector (its black and gray two halves).
I have a couple pictures but don't think they will with what your looking for.
If you can get Tom Piper's attention, he is the real electronic brain. He doesn't have PM enabled and lives in the Tallahassee area.
I have a couple pictures but don't think they will with what your looking for.
If you can get Tom Piper's attention, he is the real electronic brain. He doesn't have PM enabled and lives in the Tallahassee area.
Race Director
Joined: Aug 2003
Posts: 13,421
Likes: 8
From: Lake Mary Florida
There are two white wires on the filter. One is about 6' long, it pigtails at the end as I mentioned one to the tach and other to the ETBCM.
Here's a picture, ignore the comments I was asking some questions about where to chop it up when I spliced in a new one.
The white pigtail with pin goes to the ETBCM and the spade connector goes to the tach.
As you can see the filter comes with the gray half of the coil connector. So the other white wire is already installed from the filter to the coil. THen the pink goes to the B+.
Here's a picture, ignore the comments I was asking some questions about where to chop it up when I spliced in a new one.
The white pigtail with pin goes to the ETBCM and the spade connector goes to the tach.
As you can see the filter comes with the gray half of the coil connector. So the other white wire is already installed from the filter to the coil. THen the pink goes to the B+.
Last edited by 93JetJocky; Nov 20, 2005 at 09:59 PM.
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Thread Starter
Le Mans Master
Joined: Feb 1999
Posts: 9,959
Likes: 40
From: South Carolina
St. Jude Donor '03 & '05
Originally Posted by 93JetJocky
There are two white wires on the filter. One is about 6' long, it pigtails at the end as I mentioned one to the tach and other to the ETBCM.
Here's a picture, ignore the comments I was asking some questions about where to chop it up when I spliced in a new one.
Here's a picture, ignore the comments I was asking some questions about where to chop it up when I spliced in a new one.
Race Director
Joined: Aug 2003
Posts: 13,421
Likes: 8
From: Lake Mary Florida
I'd verify with Tom, but I would think so looking at the schematic and having had it in my hand. The way I understand it the signal is cleaned up coming out of the filter heading to the tach/ETBCM. The ETBCM needs it for retarting the timing as part of ASR.
LOL if you catch up with Tom ask him to enable his PM, we all could use that once in a while.
LOL if you catch up with Tom ask him to enable his PM, we all could use that once in a while.
Thread Starter
Le Mans Master
Joined: Feb 1999
Posts: 9,959
Likes: 40
From: South Carolina
St. Jude Donor '03 & '05
Originally Posted by 93JetJocky
I'd verify with Tom, but I would think so looking at the schematic and having had it in my hand. The way I understand it the signal is cleaned up coming out of the filter heading to the tach/ETBCM. The ETBCM needs it for retarting the timing as part of ASR.
LOL if you catch up with Tom ask him to enable his PM, we all could use that once in a while.
LOL if you catch up with Tom ask him to enable his PM, we all could use that once in a while.
Race Director
Joined: Aug 2003
Posts: 13,421
Likes: 8
From: Lake Mary Florida
I guess this is a dumb question but if it's bypassed how are you getting tach info to the tach? Doesn't that throw a code from the ETBCM?
Would the signal be on the white wire coming out of the grey coil connector that goes to the filter?
Would the signal be on the white wire coming out of the grey coil connector that goes to the filter?
Safety Car
Joined: Dec 2002
Posts: 3,655
Likes: 24
From: Charleston SC
JetJockyYou just stick a jumper wire from the input white wire to the tach filter to the output wire to bypass it. For some reason the Delteq doesn't like the tach filter inline. I removed the filter all togeather by just cutting it out then reconnecting the white wires.
Thread Starter
Le Mans Master
Joined: Feb 1999
Posts: 9,959
Likes: 40
From: South Carolina
St. Jude Donor '03 & '05
Originally Posted by FD2BLK
JetJockyYou just stick a jumper wire from the input white wire to the tach filter to the output wire to bypass it. For some reason the Delteq doesn't like the tach filter inline. I removed the filter all togeather by just cutting it out then reconnecting the white wires.
Race Director
Joined: Aug 2003
Posts: 13,421
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From: Lake Mary Florida
Ok that makes sense. Sorry I've not seen or installed one of those ignitions before.
But the output signal is still coming out of the coil connector correct? It seems like a rather simple circuit in which the signal comes out of the grey Coil connector to the filter out the filter and on to the tach and EBTCM. Course how many times has that phrase bit me, 'seems rather simple.'
Either way as I questioned above, then even if it's bypassed the coil's tach output would still be there, certainly not a cleaned signal once bypassed, but present to access correct?
But the output signal is still coming out of the coil connector correct? It seems like a rather simple circuit in which the signal comes out of the grey Coil connector to the filter out the filter and on to the tach and EBTCM. Course how many times has that phrase bit me, 'seems rather simple.'
Either way as I questioned above, then even if it's bypassed the coil's tach output would still be there, certainly not a cleaned signal once bypassed, but present to access correct?