sbrice18fan

I did a 1990 RS Camaro 305 TBI to 350 TPI swap in my signature. My only problem is that my speedo does not work. I had a 700R4 with a electronic speedo with my 305 TBI so when swaping to the TPI, I thought that I would have no problems with the speedo. I currently have a yellow and purple wire going to my VSS.

Well I posted on the DFI & ECM, TPI, and Motor Swap boards and have received no responses. Danno in the Electronics board has been most helpful. Here is the thread link: https://www.thirdgen.org/techbb2/sho...threadid=104077

Anyway, I have the 1227730 computer for a speed density system and have a Ed Wright chip, The Chilton manual shows that the Electronic speedo VSS signal goes directly to the ECM on pin's B-9, B-10. Is the computer not reciving this signal?

I called Street & Performance and they told me that I needed a signal amp. it is made by Dakota Digital. They say that the VSS is different in the TBI and TPI. Do you guys have any suggestions?

sbrice18fan

Just trying to move this up to the top and try one more time. has anybody had this problem?

Brian Shaughnessy

Personally I never had your particular problem.

But seeing as how if you go to www.dakotadigital.com and click on the accessories and find the SGI-5 speedo interface box and download the tech manual for it, you'll eventually find that they say most TBI computers use 2000 ppm and they say most TPI's are 4000 ppm. Some of us are experiencing 8000 ppm's (well, at least on my Formula when I did the T56)...

So yeah, that sounds like what you need.... either that or get a speed sensor for your tranny from a car with the same computer setup.