Speedo readout delay????
Speedo readout delay???? The guys at Williams Performance have fiinished up the Goat recently. In my 2005 GTO, they installed a 4l80e with a TCI controller. The thing that is confusing us is that under moderate to heavy acceleration the speedo stops reading until I let off the gas. At that point it jumps right up to where it is supposed to be and reads correctly. Along with the 4l80e I have a Precision 2800 stall. Any thoughts?
FormerVendor
Joined: Oct 2006
Posts: 3,123
Likes: 3
From: D-F/W
I asked T-Bones to post this in a dedicated thread as I recently experienced the same thing on a GTO we installed a 3,200 rpm stall converter into. I experienced it one time during several hard passes in the car. I did not have my scanner on it and I had to leave as soon as we got back to the shop. So, I did not have the time to try and diagnose it properly.
I spoke to my customer tonight and he told me that he saw it once prior to the converter install but did not think much of it. I will have the car back here at the shop in a couple of weeks to swap some 3.73's into it and I'll play with it then doing some data logging. We'll see how it reacts to the gear swap.
I wanted to throw this info out there while I do some research on this issue. If anyone has come across this issue please chime in.
Thanks in advance.
g
I spoke to my customer tonight and he told me that he saw it once prior to the converter install but did not think much of it. I will have the car back here at the shop in a couple of weeks to swap some 3.73's into it and I'll play with it then doing some data logging. We'll see how it reacts to the gear swap.
I wanted to throw this info out there while I do some research on this issue. If anyone has come across this issue please chime in.
Thanks in advance.
g
Actually I have spoken with several GTO owners with this issue over the past year or similar the speedo dosent work after a burnout , Then starts suddenly but while it dosent work the car will not upshift. Unfortunatley I have not heard of any fixes, Though this might not be exactly the same problem I thought it was interesting because this is also a GTO
__________________
I got a PM from another member here who is experiencing this in a TB SS. Here is what he said. "I read somewhere that it was something do to the converter (the input shaft speed sensor reading alot faster then the output speed sensor) Basicly i was told that it was read to far out of range for the pcm. I have not found any fix to this problem. If find anything out please let me know."
FormerVendor
Joined: Oct 2006
Posts: 3,123
Likes: 3
From: D-F/W
I have some folks I am talking to about it. Yes, I believe it is a Input SPeed sensor issue related to the converter swap. Basically, it is an algorythm issue. But, I would bet someone has a work around or a patch.
Stay tuned.
g
Stay tuned.
g
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From: Az
The TCI controller and 4l80e use only the output speed sensor for vehicle speed. How do you have it wired from the TCI controller to you Cluster? Or are you sending the TCI controller Speed to you PCM?
I don't have a delay, but I've been fighting issues of my cluster not reading the correct speed. I swapped from a six speed to a TH400. I'm using a 40 tooth reluctor that normal automatic GTO's use. You can change the settings in HP Tuners to get what the computer is sensing for speed to change, but the cluster doesn't change at all. It reads 105 for an actual 75mph. I've been pulling my hair out trying to figure this thing out.
I've had this happend also. The speedo will quit working after I do my burnout or launch. It will not start to work again untill I shift the car back into D. I was told to check the speed sensors in the rear and make sure they are clean. I haven't ever got around to doing it but thats my lil input on it.
I've had this happend also. The speedo will quit working after I do my burnout or launch. It will not start to work again untill I shift the car back into D. I was told to check the speed sensors in the rear and make sure they are clean. I haven't ever got around to doing it but thats my lil input on it.
The fix for mine is to run a Jet Accu-Speed part no. 50108. That allows you to manipulate the signal coming from the trans. Here is a write up someone PM'd me.
"It was easy to wire all you need is a 12volt source and ground. I put mine in the center console. I ran the green and purple wire through the firewall by the clutch. You have to tap into the purple and white wire on the top pcu tap. You have to be careful there are like 3 purple wires with white tracer. I think it was the one that went to pin 19. can't remember it was easy for me to find because I had already tapped that same one when I installed my nitrous controller last year. Green wire on jet goes to pcu side after you cut wire. Purple wire goes to side that goes to speedo. All you do is wire it in series green on cpu side of cut with Purple wire going to dash simple. If I get a chance I will try to check what pin its on. LOL don't really want to rip all that wire harness shielding off again. Friend of mine looked it up online for the wire diagram to find out exactly what pin because there were three.
It works great so far the only issue I have had is the speedo will get a quick spike on startup and show speed for a second. Other than that it works great."
"It was easy to wire all you need is a 12volt source and ground. I put mine in the center console. I ran the green and purple wire through the firewall by the clutch. You have to tap into the purple and white wire on the top pcu tap. You have to be careful there are like 3 purple wires with white tracer. I think it was the one that went to pin 19. can't remember it was easy for me to find because I had already tapped that same one when I installed my nitrous controller last year. Green wire on jet goes to pcu side after you cut wire. Purple wire goes to side that goes to speedo. All you do is wire it in series green on cpu side of cut with Purple wire going to dash simple. If I get a chance I will try to check what pin its on. LOL don't really want to rip all that wire harness shielding off again. Friend of mine looked it up online for the wire diagram to find out exactly what pin because there were three.
It works great so far the only issue I have had is the speedo will get a quick spike on startup and show speed for a second. Other than that it works great."
I also have a delay on the tach sometimes too. its usually if im WOT then let off and the trans shifts gears it will hang in the high RPMs coming down slowly, then drop to 2k or where ever it should be
