Wrong speed indicated in Tunepro.

[jon]

After spending quite a bit of time understanding tunepro and making adjustments to the tune I am happy to say my modified 5 L is purring like a kitten as long as it idling
I moved onto the next stage and took the car for a drive to log some data and apart from stopping a couple of times to richen up the VE table everything went well.
When I got back home and re played the log file I noticed the speed indicated in the log was way off the mark. I got up to about 70km/h at one stage and the log in tunepro only said I got to 8km/h??
The car is a series 1 VN calais but used to be a V6. I dropped a 5L V8 from a series 2 VN in it and apart from a couple of plugs different near the computer everything dropped straight in.
The car is fitted with a Jaycar kit to correct the speedo as it has 3.7LSD in it. The speedo itself works perfectly and is very accurate.
I am guessing that if the log from tunepro is wrong then the ecu is getting the wrong speed input?
This normally wouldnt be a problem as it is not logging any fault codes that I know of but if the ecu is not reading the right speed then the torque converter will never lock??
This is a feature I would really love as the stall converter is 3500 and torque converter lockup will drop the rpm's a little on the highway.
Could the jaycar kit be causing problems to the ecu or could I be missing something else?
Thanks, Jon

[Dazza92VP]

by the sounds of it your pulses per kilometer are out the standard pulses per k are 1250.05 for a 3.08 ratio diff but seeing as you have a 3.7 it should be 1501.00 pulses per kilometer id start by checking that

[The1]

is the speed input hooked upto the ecu? diff should not affect the reading that much

[Holden202T]

if its ose $12P code it might have the VR numbers in the PPK 6000 or something ...

[jon]

The jaycar kit breaks into the signal wire not far from the sensor and before the dash. I havent got a wiring diagram in front of me but I thought the ecu gets its signal from the dash? The dash is showing the correct speed (checked with GPS).
The only thing I could think of is the output waveform from the jaycar kit the ecu is not happy with? But then I thought the dash itself has a divider circuit to reduce the pulse rate?
Its been a while since I have played with that part of it. Was wondering if someone else has had a similar issue
Jon

[jon]

It is ose $12P code.
Jon

[Dazza92VP]

yea i had the same problem when i converted my stato over to 12p had the vr pulses in it. i missed the jaycar kit in it though so standard pulses 1250.05 should be right

[jon]

Thanks so much for the help. Will give that a try and see how that goes

[jon]

Just a quick update on this topic. I changed the pulses to 1250 and the speed displayed in TP is perfect. Thanks so much for the help!