VSS and a 3 speed

[87bigcut]

If I have a 3 speed transmission (th350) that is going behind a GN motor in my cutlass do I need a working VSS sensor? The reason I ask is the 442 gauge cluster I swapped in doesnt have a provision for one. It is a non lockup th350. Also do I need a special chip or something to run a 3 speed transmission with a GN ECU? I searched for info on this but couldnt find anything.

Thanks,
Joe

 

[GNut]

Regardless of what transmission you use, the stock ECM needs to see a speed input. Since you've swapped out the stock speedo cluster with one from another vehicle, the VSS input which is generated by the stock GN cluster will no longer provide that signal. The answer is an external VSS wired into the old VSS output wires (green/black/red w/ the little black plug that attached to your old stock cluster). I have them available for $115

Tom Houser
Performance Instruments
www.gnxdash.com

 

[turbotwister]

Hi,
If you are running a th-350 you do not need a speed input into the computer.a chip burner like eric marshall from TURBOTWEAK can program your chip so that your car doesnt need the input.not to mention his ability to make an excellent chip .e-mail him .he can give you the details.

Nick,

 

[87bigcut]

Thats the info I was looking for. Also, someone told me it would be a pain to wire the Olds Gauges I have to work with the GN motor. Anyone have any details on this? I'm going to pick up the motor next weekend so I will email TURBOTWEAK after I have it in my hands.

Thanks,
Joe

 

[GNut]

The engine harness and dash harness are completely separate harnesses but if you go through both wiring diagrams for both cars, you should be able to match up most of the dash functions. Something to remember is that the Buick does NOT have senders for actual analog type gauges (Oil press, Water temp, etc.) You'd probably have to use the Olds senders to get those functions to work if they are in the Olds dash. Keep in mind that most gauges function through a single sender input wire as long as they are wired for power. It might be a pain...but it can be done. As far as using a chip to eliminate the VSS...why? I honestly don't see the benefit in "tricking" the computer to see something that isn't there. How will the ECM know when to go into PE mode?? I'm no chip guru.. but why mess with a system that works when used properly?

Tom Houser
Performance Instruments
www.gnxdash.com

 

[turbotwister]

im really not exactly sure how he does these things.all i know is that i have had him do many different things for me that seem like they wont work or you shouldnt do and he finds a way.his solutions seem to work well everytime.get in touch with him.im sure he will give you the answers you need.


nick,

 

[turbofish38]

What year of speedo/cluster are you using? If it is newer than 80 than there is a provision for the stock TR VSS(assuming it is from an analog dash) on the back of the speedo, if you want to retain the stock VSS functions.

 

[87bigcut]

IM not sure what PE mode is...Please explain.

Also, I thought the VSS controlled when the converter locked up, and since I dont have a locking converter it would be useless. That is unless it has another function. How do people with autometer gauges hook up the VSS?

Thanks,
Joe

 

[GNut]

PE Mode is "power enrichment mode", it's controlled by the ECM and senses that the engine is operating at a certain RPM and that the car is moving at a certain speed. It's not activated soley by the VSS but it plays into the whole picture. Bottom line is, if you'll be using the stock Buick GN/TR computer, you really should have the VSS input. The guys using aftermarket dashes that I build use an external VSS.

Tom Houser
Performance Instruments
www.gnxdash.com

 

[87bigcut]

I am using a 1986 olds 442 cluster. It has a boss for the VSS but it is filled in. I wonder if they had a different VSS because all those cars had 4 speeds if I remember correctly. My car was originally metric 200 tranny so if that had a VSS why wouldnt a th200-4r in a 442? Anyone running a 3 speed behind a GN motor does TURBOTWEAK's chip solve the problem fully? I'm gonna e-mail him right now.

Thanks,
Joe

 

[GNut]

Well, on some junkyard hunts I've been on I've found VSS's located in different locations on different cars. Most newer cars use a VSS that's connected directly to the transmission. Again.. Bottom line for the BUICK GN/TR drive train and ECM is a VSS that generates a 2 pulse per revolution signal to the ECM. If you're going to use a stock buick ECM to control a LC2 Turbo V6... a VSS signal is necessary or it will throw a code shortly after it gets rolling. I'm sure it's possible that a Chip Guru can program a chip that tells the ECM to ignore that signal... but what would you gain from it?

Tom