mystingray1

i am about to do a f.i.r.s.t tpi conversion on my 81 and am wondering do i need a vehicle speed sensor? they didn't send one and frankly i am not even sure how or where that would go, will the ecu function fine without it?

Rotonda

The main function of the VSS in the TPI system is to control the idle speed when you lift throttle while moving. If you have a manual tranny, you can definitely get along without it. If you are using an automatic, you will be happier if you run a VSS.

Please note that early TPI VSS is 2000 pulse while later is 4000 pulse.

If you need help, PM me. I am running TPI with a 700R4 and VSS. It is not difficult to do.

lionelhutz

Yes, you need one. Many of the ECM functions are tied into the VSS signal.

mystingray1

Thanks I could use some help on this one as I have no idea what components I need, where to get them or how this ties in with my 700r4

mystingray1

There are no instructions in the efi manual and no hardware for this, just a couple of wires with no connector that are marked speed sensor

lionelhutz

You can start by telling us what computer you are using.

mystingray1

I received and ecu from affordable fuel injection with a chip that is supposedly set for my configuration, with 330k on the motor i will be rebuilding in the future and will probably hit the dyno then for optimized chip.

mrvette

The typical 1227730 GM computer will send the engine into an idle hunt mode with the idle drifting around 1000 rpm without a VSS signal, you need spend some bux and go on ebay and find a 4000 ppm sender that will screw into the trans, then the cable screw into it.....and of course hook up the wires, mine were purple and yellow....

lionelhutz

OK, but it should have service number on it.

carriljc

The tach cable adapter attached to the tranny, then the VSS installed, then the regular cable went to the speedometer.
Worked just super.

Part numbers below are about 10-12 years old, but perhaps they can cross-reference for you if you contact suppliers.

I'd look around some, because the price on that VSS has doubled since I bought it. Seems a bit much but there it is.

Not sure MA has that tach cable adapter(can't find it?) on their mamotorworks site. If you look for "tach cable extension" on the net you should be able to find a short cable instead.

Painless VSS from Summit, PRF-60116.

Tach Cable adapter from Mid America Corvette for VSS.
609465

But REALLY need to know your ECM number --

mystingray1

Thanks, i

mystingray1

Thanks, I will try and get numbers off of the ecm tonight

carriljc

for my old 730 ECM....
easy enough to use short cable from tranny to vss, insert vss, then the regular speedo cable goes off to the speedometer.

Since you already have the chip burned and the ECM, then I understand what you are doing. Otherwise, I would recommend a newer self-learning system.