LS1 comuputer on LT1
Registered User
Joined: Nov 2001
Posts: 3,515
From: Kansas
Originally posted by Injuneer
Once you have that signal, all you need is a chip that produces the low res pulse pattern each time the chip is triggered by the crank sensor. Then you need to correct the timing of the pulse pattern based on comparing the pulse signal to a crank trigger signal, to keep them in synch.
The E'motive chip synthesizes the low res pulse pattern from a crank trigger, so it would seem that something similar could be done along the lines of what I outlined.
Just throwing some thoughts out... not a lot of in-depth thinking behind them, just random thoughts.
Once you have that signal, all you need is a chip that produces the low res pulse pattern each time the chip is triggered by the crank sensor. Then you need to correct the timing of the pulse pattern based on comparing the pulse signal to a crank trigger signal, to keep them in synch.
The E'motive chip synthesizes the low res pulse pattern from a crank trigger, so it would seem that something similar could be done along the lines of what I outlined.
Just throwing some thoughts out... not a lot of in-depth thinking behind them, just random thoughts.
Registered User
Joined: Apr 2000
Posts: 300
From: Hudson,MA currently Worcester, MA
I'm using the coil pack setup but I have a F.A.S.T system.
You can see pics here http://www.96z28ss.cz28.com/photo.html
It has a cam sync and a crank trigger.
I know its expensive to do a system like this but this is the way to go. the opti is nothing but problems.
rob
You can see pics here http://www.96z28ss.cz28.com/photo.html
It has a cam sync and a crank trigger.
I know its expensive to do a system like this but this is the way to go. the opti is nothing but problems.
rob
Registered User
Joined: Apr 1999
Posts: 120
From: Eastern Seaboard
The problem with the E'motive setup is that it uses a crank trigger which can fire the injectors 180° out of phase (which isn't a problem with the batch-fire LT1's from 92 and 93).
I've tried contacting E'motive about using a cam sensor, and they never respond. They are definately not customer oriented (at least in my experience), and forget about ANY help with an older system from them. They are quick to respond when you tell them you're interested in buying a new system though
I've tried contacting E'motive about using a cam sensor, and they never respond. They are definately not customer oriented (at least in my experience), and forget about ANY help with an older system from them. They are quick to respond when you tell them you're interested in buying a new system though
Registered User
Joined: Jun 2002
Posts: 243
From: TN
quote:
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Correcting the LS1 computer firing order to the LT1 engine firing order should be as simple as hooking up the injector wires in the correct order, and hooking the individual coils to the correct plug. Where you might get into problems would be in the misfire detection, where the PCM is looking for a specific pattern in the irregularities of the crank.
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Would the tooth learn error mode take care of this and do the obd2 lt1 computers have this mode?
Any idea if the crank position sensor from a '96-'97 is compatable with what the ls1 computer uses?
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Correcting the LS1 computer firing order to the LT1 engine firing order should be as simple as hooking up the injector wires in the correct order, and hooking the individual coils to the correct plug. Where you might get into problems would be in the misfire detection, where the PCM is looking for a specific pattern in the irregularities of the crank.
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Would the tooth learn error mode take care of this and do the obd2 lt1 computers have this mode?
Any idea if the crank position sensor from a '96-'97 is compatable with what the ls1 computer uses?
Last edited by 96ltz; Mar 7, 2003 at 08:00 PM.
Registered User
Joined: Mar 2002
Posts: 3,082
From: San Juan PR
Has anyone ever addressed this???
I thought that the LS1 PCM you could change the firing order of the engine as well as how many cylinders it has, the V6 pcms are the same than the ls1 pcms... so...
Why so much trouble with a cam sensor? i guess it SHOULDN't be that difficult if you have a cam sensor the LS1 PCM can understand. forget about the lt1 pcm as its the one being ditched...
Im interested in this...
THnanks
I can post all diagrams if needed in the next couple of days as I have them in the PC.
let me know if any of that helps or if it would be a good project. I like the idea of using the true LS1 pcm on my LT1... I wouldn't thing its IMPOSSIBLE...
I thought that the LS1 PCM you could change the firing order of the engine as well as how many cylinders it has, the V6 pcms are the same than the ls1 pcms... so...
Why so much trouble with a cam sensor? i guess it SHOULDN't be that difficult if you have a cam sensor the LS1 PCM can understand. forget about the lt1 pcm as its the one being ditched...
Im interested in this...
THnanks
I can post all diagrams if needed in the next couple of days as I have them in the PC.
let me know if any of that helps or if it would be a good project. I like the idea of using the true LS1 pcm on my LT1... I wouldn't thing its IMPOSSIBLE...
Registered User
Joined: Mar 2002
Posts: 3,082
From: San Juan PR
after checking alldata...
THE CMP is just a "reference signal" to know where the valvtrain is related to the CKP. So the one that really pulses the injectors is the crankshaft position sensor. The CMP is an on off switch once per revolution.
The CKP is 24 pulse... and it will identify which 2 is in TDC.
Maybe this helps
THE CMP is just a "reference signal" to know where the valvtrain is related to the CKP. So the one that really pulses the injectors is the crankshaft position sensor. The CMP is an on off switch once per revolution.
The CKP is 24 pulse... and it will identify which 2 is in TDC.
Maybe this helps
Registered User
Joined: Mar 2002
Posts: 3,082
From: San Juan PR
After doing a bit of research.. this is what it can be done:
it would make an interesting project none the less.. i might try it if i get my hands on a wiring harness...
This WILL eliminate the opti...
It would require that the reluctor wheel from the ls1 be "retrofitted" to the lt1 96 timing cover... the reluctor wheel for the ls1 is 24x and the lt1 is 4x... changing the reluctor wheel (if its possible) and changing the CKP sensor maybe a simple bolt on operation or minor modifications...
YOu do NOT need the camshaft position sensors.. the l31 engine on some trucks do not use a cam position sensor, yet it starts up and no problems and i believe the PCM is an ls1 derived pcm.. or something in the likes...
the cam sensor is just a "synch" it will set a code that can be edited with ls1edit...
I think that this would make a nice playgruond... i have an ls1pcm laying around that i might try and use
it would make an interesting project none the less.. i might try it if i get my hands on a wiring harness...
This WILL eliminate the opti...
It would require that the reluctor wheel from the ls1 be "retrofitted" to the lt1 96 timing cover... the reluctor wheel for the ls1 is 24x and the lt1 is 4x... changing the reluctor wheel (if its possible) and changing the CKP sensor maybe a simple bolt on operation or minor modifications...
YOu do NOT need the camshaft position sensors.. the l31 engine on some trucks do not use a cam position sensor, yet it starts up and no problems and i believe the PCM is an ls1 derived pcm.. or something in the likes...
the cam sensor is just a "synch" it will set a code that can be edited with ls1edit...
I think that this would make a nice playgruond... i have an ls1pcm laying around that i might try and use
Registered User
Joined: Mar 2002
Posts: 3,082
From: San Juan PR
Can you please elaborate on that nitrous control???
did you guys used the unused A/D pins and added code to the pcm to do this???
It would be an aweosme idea if you can retrofit the ls1 pcm into the lt1 w/o hitches, remove the opti, have the 8 coils.. have ALDL.. tranny, tach, speedo, and still be able to see boost correctly using a 2 bar map sensor from starrperformance...
did you guys used the unused A/D pins and added code to the pcm to do this???
It would be an aweosme idea if you can retrofit the ls1 pcm into the lt1 w/o hitches, remove the opti, have the 8 coils.. have ALDL.. tranny, tach, speedo, and still be able to see boost correctly using a 2 bar map sensor from starrperformance...
Registered User
Joined: Jan 2000
Posts: 377
From: San Diego, CA
Wouldn't an easier and cheaper solution be adapting a 91-92 SD TPI computer/harness and mounting a distributor in the back of the intake? As long as you don't have a 4L60E you should be fine.
I've never really had a problem with opti-sparks though.. I think If I do I'd rather ditch the LT1 and just go straight to an LS1/SBC rather than tinkering with opti elimination that may or may not work.
As long as you don't have a 4L60E you should be fine. I've never really had a problem with opti-sparks though.. I think If I do I'd rather ditch the LT1 and just go straight to an LS1/SBC rather than tinkering with opti elimination that may or may not work.