scanmaster mph reading

[AlaskaGN]

my scanmaster mph reading about half of what my speedo is. What is causing this? Is it hurting my performance or driveability any?

 

[Just a Six??]

I would go directly to full throttle speed forums page & ask Bob since he invented the thing. Lots of other great info there as well.

 

[whitehot1]

+1 FullThrottleSpeed tech forums will most likely be the best place for help on this problem with the scanmaster.

Here is a link to their tech forums.

Full Throttle Speed Tech Support - Powered by vBulletin


John :smile:

 

[Jerryl]

Does/Did the car have a 145mph speedometer?
The MPH indicator accuracy is pretty important as it is used to calculate load variable/fueling.

 

[AlaskaGN]

no it came with an 85 mph gauge and I put a 145 mph plate on it years ago. never did anything with sensors or anything. thanks for your help everyone. Ill check out the full throttle link.

 

[Mike Licht]

did you put a speedo reducer on th trans to make that plate work? that is your problem

 

[SNOWBIRD]

JERRYL....Are you saying that if you disconnect the speedo cable it will affect fueling..??????????....VSS

 

[aminga]

JERRYL....Are you saying that if you disconnect the speedo cable it will affect fueling..??????????....VSS

Yes.

 

[SNOWBIRD]

OK ,then i have another question ,I purchased a GN made in the usa 7 years ago and put in a used speedo cluster that was in kilometers ,I am in canada..it had a hole for a vss and i bolted it in..how would i know if vss is working or not????

 

[SNOWBIRD]

The Cluster Was From A Standard Regal Not A Gn

 

[AlaskaGN]

Mike, no I didnt put a speed reducer on the trans. If that is the problem where could I find one and how much $ ?. WOuld the speed reducer make the SM read higher or the speedo slow down? the speedo seems real close to the actual speed the car is going, and the sm a lot less.

 

[turbojd]

The reducer slows down the speedometer to match the 145 speedometer overlay, the scanmaster/ecm reads the actual slower speed thats being reported to the VSS. If you run a lockup converter it will delay the converter lock up until the VSS sees 45 mph or whatever your chip is programmed to lock up at.

 

[Jerryl]

JERRYL....Are you saying that if you disconnect the speedo cable it will affect fueling..??????????....VSS

I think you got the answer in the other reply.

AlaskaGN,
If you don't have a TT chip, get one burned to ignore the speedo input, or, "just fix it".

 

[PaintedIron]

I would go directly to full throttle speed forums page & ask Bob since he invented the thing. Lots of other great info there as well.

I find myself browsing through there constantly as well.