Installed 90mm tb. Wont Run!! Help please.
03-09-2006, 08:38 AM
#41
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Originally Posted by JimS
If I change the TAC which one should I go to? Will this change make for a problem between the TAC and the pcm? Will the pcm have to be reprogramed to recognize an 03 TAC.
I guess if I order the same part number TAC but stipulate it's for an 03 truck that should maybe get a TAC that the tb will recognize?
Wait. The pcm is recognizing the TAC. How can the TAC be the problem? Doesn't the problem have to be either the harness or the tb?
I guess if I order the same part number TAC but stipulate it's for an 03 truck that should maybe get a TAC that the tb will recognize?
Wait. The pcm is recognizing the TAC. How can the TAC be the problem? Doesn't the problem have to be either the harness or the tb?
If it makes you feel better Jim, i'm drinking a beer for you right now.
03-09-2006, 09:23 AM
#43
Got busy last night working on my J-tube. Just looked at all the wiring diagrams. Jim I don't see any difference between your truck and my 04. Your TAC module should be OK. It better be because the one I got shows that it is for an 02 and is the same part # as yours and what has been listed here.
I looked at my OEM connector as well as the Speartech harness. On my STH it looks like the high and low reference wires are switched around. Looking at the STH connector as shown in the pic below the wire colors are:
Grey/Yellow/Brown
Purple/Black/Green
Looks like they should be:
Black/Yellow/Brown
Purple/Grey/Green
What does yours look like?
One each of the OEM high and low ref wires are deleted going into the STH because the LS2 TB only uses one of each.
I looked at my OEM connector as well as the Speartech harness. On my STH it looks like the high and low reference wires are switched around. Looking at the STH connector as shown in the pic below the wire colors are:
Grey/Yellow/Brown
Purple/Black/Green
Looks like they should be:
Black/Yellow/Brown
Purple/Grey/Green
What does yours look like?
One each of the OEM high and low ref wires are deleted going into the STH because the LS2 TB only uses one of each.
03-09-2006, 09:27 AM
#44
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Spoke with John Spears this morning and he can't figure out why the truck would run just fine after the codes are reset and then when shut off and the key turned back on the codes come back. The SES light does NOT come on while it's running but are it's lit up after the key is turned back on.
When I try to start it without resetting the codes one of three things happens. Sometimes it won't start. Sometimes it tries to start and just sputters. Other times it starts, runs at idle of about 1k and then the idle increases to about 2k and the accelator won't function... press down on the accelerator and nothing happens... then the Reduced Engine Power light comes on with the SES light. Codes are always the same.
Nothing makes sense.
If it was the wiring then it would be there all the time and the truck wouldn't start and run just fine right after the codes are cleared.
If it was the TAC it would have been there with the old tb. The TAC is the right one for this application as only the 01 and 02 TAC's will work with the tb because the Corvette uses the 01/02 TAC module. Speartech set up this conversion using this tb and this TAC and my part numbers check out. I checked my invoice with the part number given in the conversion thread and it's right. I wonder if the tb I actually got is the one shown on the invoice? I could try to check that out..... it looks the same.
It almost has to be a problem with the tb so I'm sending it to Spears to check it out. He has engines he can bolt it up to and see if the tb works in his set up.
When I try to start it without resetting the codes one of three things happens. Sometimes it won't start. Sometimes it tries to start and just sputters. Other times it starts, runs at idle of about 1k and then the idle increases to about 2k and the accelator won't function... press down on the accelerator and nothing happens... then the Reduced Engine Power light comes on with the SES light. Codes are always the same.
Nothing makes sense.
If it was the wiring then it would be there all the time and the truck wouldn't start and run just fine right after the codes are cleared.
If it was the TAC it would have been there with the old tb. The TAC is the right one for this application as only the 01 and 02 TAC's will work with the tb because the Corvette uses the 01/02 TAC module. Speartech set up this conversion using this tb and this TAC and my part numbers check out. I checked my invoice with the part number given in the conversion thread and it's right. I wonder if the tb I actually got is the one shown on the invoice? I could try to check that out..... it looks the same.
It almost has to be a problem with the tb so I'm sending it to Spears to check it out. He has engines he can bolt it up to and see if the tb works in his set up.
03-09-2006, 09:31 AM
#45
Oops.
It also depends how they have the other end of the harness wired on yours.
Looking at the STH 8 pin connector the same way I have:
yellow/empty/brown/black
grey/purple/green/empty
BTW. I believe that having the high/low refs switched would cause both sensors to be out of range as the voltages would be moving in the opposite directions of what the PCM expects. One starts off high and decreases as the throttle opens while the other starts low and increases with throttle opening. TP Sensor 1 would be doing what was expected of TP Sensor 2 and vive versa.
It also depends how they have the other end of the harness wired on yours.
Looking at the STH 8 pin connector the same way I have:
yellow/empty/brown/black
grey/purple/green/empty
BTW. I believe that having the high/low refs switched would cause both sensors to be out of range as the voltages would be moving in the opposite directions of what the PCM expects. One starts off high and decreases as the throttle opens while the other starts low and increases with throttle opening. TP Sensor 1 would be doing what was expected of TP Sensor 2 and vive versa.
Last edited by DrX; 03-09-2006 at 09:47 AM.
03-09-2006, 01:03 PM
#46
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Originally Posted by DrX
Got busy last night working on my J-tube. Just looked at all the wiring diagrams. Jim I don't see any difference between your truck and my 04. Your TAC module should be OK. It better be because the one I got shows that it is for an 02 and is the same part # as yours and what has been listed here.
I looked at my OEM connector as well as the Speartech harness. On my STH it looks like the high and low reference wires are switched around. Looking at the STH connector as shown in the pic below the wire colors are:
Grey/Yellow/Brown
Purple/Black/Green
Looks like they should be:
Black/Yellow/Brown
Purple/Grey/Green
What does yours look like?
One each of the OEM high and low ref wires are deleted going into the STH because the LS2 TB only uses one of each.
I looked at my OEM connector as well as the Speartech harness. On my STH it looks like the high and low reference wires are switched around. Looking at the STH connector as shown in the pic below the wire colors are:
Grey/Yellow/Brown
Purple/Black/Green
Looks like they should be:
Black/Yellow/Brown
Purple/Grey/Green
What does yours look like?
One each of the OEM high and low ref wires are deleted going into the STH because the LS2 TB only uses one of each.
My sth plug colors, where it plugs into the tb and with the plug oriented as shown in DrX's photo, are green/yellow/brown across the top and on the bottom pink, purple and blue
As I said my stock set up has a 6 prong plug and a seperate 2 prong plug. The colors on the STH dont match up with the colors on the 6 prong plug but I told Spear about it and he says it's ok. He designed the whole conversion so ought to be good.
Looking down on the 6 pin plug and with the clip up and the clip down on the stock harness the wires colors are as follows: Sth green to stock wht, sth purple to stock black, sth blue go stock green, two blank sth with stock blue and blk & white and last, sth pink to stock purple.
I hooked up the stock tg and tried it without bolting it on and it functions with the accelerator. I then tried to start the truck with the 90mm and it wouldn't start and after a few tries I got the strong odor of gasoline. I disconnected the 90mm and sent it to Speartech for him to test. Maybe (I Hope!!) the 90mm tb is ng.
So now it'll be a few days again.
Last edited by JimS; 03-09-2006 at 01:11 PM.
03-09-2006, 01:43 PM
#47
Looks like your wiring and wire colors are the same as the newer trucks its just that you have 2 connectors (6+2) instead of 1 (8 Pin) because the TB is different. The colors on the STH are irrelevant as long as the correct OEM wires are linked to the correct pins on the LS2 connector. Speartech will figure it out.
03-09-2006, 02:29 PM
#48
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Originally Posted by DrX
Oops.
It also depends how they have the other end of the harness wired on yours.
Looking at the STH 8 pin connector the same way I have:
yellow/empty/brown/black
grey/purple/green/empty
BTW. I believe that having the high/low refs switched would cause both sensors to be out of range as the voltages would be moving in the opposite directions of what the PCM expects. One starts off high and decreases as the throttle opens while the other starts low and increases with throttle opening. TP Sensor 1 would be doing what was expected of TP Sensor 2 and vive versa.
It also depends how they have the other end of the harness wired on yours.
Looking at the STH 8 pin connector the same way I have:
yellow/empty/brown/black
grey/purple/green/empty
BTW. I believe that having the high/low refs switched would cause both sensors to be out of range as the voltages would be moving in the opposite directions of what the PCM expects. One starts off high and decreases as the throttle opens while the other starts low and increases with throttle opening. TP Sensor 1 would be doing what was expected of TP Sensor 2 and vive versa.
03-09-2006, 03:27 PM
#49
Originally Posted by JimS
"both sensors out of range" Does that mean they would throw a code such as I've been getting? Why would it run great after the codes are removed but not start after being shut off? Nothing seems to explain that.
Here are the OEM wire colours as they match up to the LS2 connector oriented as shown previously. You can trace the wires in the STH to see if they mate the proper pins up with these wires in the OEM harness.
black/yellow/brown
purple/blue/green
the black/w and grey OEM wires are not used for the LS2
Last edited by DrX; 03-09-2006 at 03:38 PM.
