VSS

[Speedo]

I have searched and found conflicting information, it seems that the Gen III engines will run without a vss but some say that there are some problems in not using a vss. For general information I have a 2000 5.3l in front of a TH-400 that will be going in a buggy. I have read that there can be problems when going to idle position while still moving and that full performance requires vss.

Since I have a non-computer controlled tranny and I have no speedometer what function does the vss have as far as the engine is concerned?

Thanks,
Gus

[RedHeartbeat]

It tells the PCM when to fatten up the fuel mixture. WOT with no transmission load takes less fuel than WOT with the tires spinning 90 MPH.

[Speedo]

<div class='quotetop'>QUOTE(RedHeartbeat &#064; Jul 12 2007, 12&#58;40 PM) [snapback]99266[/snapback]</div>

It tells the PCM when to fatten up the fuel mixture. WOT with no transmission load takes less fuel than WOT with the tires spinning 90 MPH.
[/b]

Doesn&#39;t the MAP sensor give the PCM load info? Is the vss in addition? I don&#39;t understand what part of the mapping the vss controls. Sorry, I would just like to learn as much as I can about the functions of the sensors and what I can do without.

Gus

[airdeano]

vss is for shifting, TCC, emissions...
there are no speed maps in the programming for air/fuel/timing.
only time speed is needed is for highway mode.

airdeano