I using the 8D bin for my 454 / TH400 MPFI engine. I was wondering how I should program the Highway Mode Spark. I am using TunerPro and a Moate.net Burn2 Prom Burner.

The TH400 does not have a 4th gear or a Torque Converter Clutch. Is there a Constant(s) / Scalar(s) or Flag(s) / Switch(s) I should set / unset?

I've attached a screen shot of some of the Highway Mode Spark Constant / Scalars.

Thanks,
dave w

 

do you have a vss hooked up?


if so, it would be used like normal. there's not a 4th gear flag that i know of. just set the mph you want it to go into highway at and the min coolant temp.

if not, then i think i saw a thread somewhere of a guy that run it with no vss, but i don;t know if it worked. something like mph set to 0 and used the timer to delay it a while before it kicked in.

 

Thanks for the reply. No VSS yet. I'll do a search for posts 8D not using VSS. I'm sure someone has an 8D without VSS? Then I'll see what I can figure out from that information. Any suggestions on an aftermarket VSS, I might go that direction at a later date.

 

i don't know what the easiest way to add a vss is, but i do know there's a very long thread about adding vss to a th400, or something like that.


here's 2 quick links i found

https://www.thirdgen.org/forums/diy-...e-without.html

https://www.thirdgen.org/forums/diy-...-settings.html


from what i've read. the vss is a pretty big deal. lots of drivablitly things are based on it. so it may be worth your while to have one.

 

you defiantly want to get the VSS working, otherwise you'll be banging your head on the wall trying to get it tuned right.
without a good VSS signal, the ECM will be stuck in idle cell 4.
before playing with hiway mode, you need to have your fuel and spark tables pretty close which you can't really do with it in cell 4.
there are also some other things the ECM needs the VSS signal for.

 

I think I'll order this VSS http://howellefi.com/customer/produc...1&cat=0&page=1

Any other options for a VSS?

dave w

 

i like that looks simple and to the point.

double check the ppm output. your ecm is looking for 4000 ppm. it can be adjusted in the ecm but it may make life easier if its 4k already, or is adjustable would be even better. that is if you plan on using the speedo output from your ecm to a stock speedo.