Speed doesnt go above 30ish
Thread Starter
Teching In
Joined: Mar 2011
Posts: 40
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From: Las Vegas
Speed doesnt go above 30ish I've got a ls1 swap 95. The issue in having is my speed is about half of what I'm actually doing. I had the comp Mail order tuned and after having a second local tuner check out the tune the tires and gearing was wrong. On top of that they couldn't let him change it. So we put on a new operating system and tried again. This time we could change it but the reading from the obd2 port and speedo stayed about half. It's a 99 computer and the harnesses have been swapped also from ls fbodies. The gauge cluster im not sure the exact year but its 98+.
The weird thing I that the comp matches the speedo even after all the changes to tires and gears with hp tuners.
Please help.
The weird thing I that the comp matches the speedo even after all the changes to tires and gears with hp tuners.
Please help.
What transmission? The vss should be on the transmission. Did you tap the vss signal from the transmission to get the gauge to work or did you use the vss output from the ecm? You need to know what the vss sensor output signal is and make sure the pcm is calibrated for it . The pcm vss output can be changed to match the gauge you use.
Thread Starter
Teching In
Joined: Mar 2011
Posts: 40
Likes: 0
From: Las Vegas
its a t56. i did not tap any wires. the signal is coming from the vss through the cpm. The cpm is a 99 the tranny I'm not sure the gauges I'm not sure either. The weird thing is that no matter what gear ratio the tuner plugged into the comp it didn't change.
side note
i had to get a few different gauges due to the lcd readout being messed up and needles stuck. what do i need to do to calibrate it?
side note
i had to get a few different gauges due to the lcd readout being messed up and needles stuck. what do i need to do to calibrate it?
What are you using to tune it? The transmission vss output needs to match in the tune.
Is the pcm seeing the correct speed? If it is then you can change the pcm vss signal output to match the gauge in the tune.
Is the pcm seeing the correct speed? If it is then you can change the pcm vss signal output to match the gauge in the tune.
Thread Starter
Teching In
Joined: Mar 2011
Posts: 40
Likes: 0
From: Las Vegas
the guy is using hptuner. the comp matches the gauge but it is not the actual speed.
are the vss different from year to year? if so would i just be able to buy a 99 vss then that would avoid the issues?
are the vss different from year to year? if so would i just be able to buy a 99 vss then that would avoid the issues?
I dont know if they change from year to year. sounds like the output is correct . Its the input that needs to be tweaked. There should be a table that changes the signal input variable . 1k,2k,4k, 8k,10k, etc. You might have a bad vss to begin with . Or the sensor could be too far from the reluctor. On second thought ... the vss sensor should just be a pickup. The reluctor is what would change i would think . . Im just trying to throw ya ideas as im no expert in tuning.
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Its the reluctor that is different. Change the vss input to 11ppr and see if it changes the speedo/ecm output. on the third gen board i found this topic . up to 93 the trans used a 11ppr vss signal . 94+ uses a 17ppr signal. And after more reading ... If it is a 93 transmission , It can have the 11 tooth reluctor and a different vss. If the reading is still incorrect go with the 99 vss .
Last edited by Emdmechanic; Jul 12, 2012 at 11:20 AM.
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Verdad Gallardo Thread Starter
Teching In
Joined: Mar 2011
Posts: 40
Likes: 0
From: Las Vegas
i need somewhere to start I'm glad you gave me some info. ill research some more. From what i noticed the sensor is the same. ill call the tuner later and see.
Keep the info coming i need to fit this cuz the gauge reads about 1/3 the cars actual speed.
Keep the info coming i need to fit this cuz the gauge reads about 1/3 the cars actual speed.
