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Tech / General EngineIs your car making a strange sound or won't start? Thinking of adding power with a new combination? Need other technical information or engine specific advice? Don't see another board for your problem? Post it here!
I have a 91 Z/28 that had a factory 305TPI.. I swapped the old engine out and built a 383 TPI and replaced the factory wiring with this new Fitech ultimate TPI... I am having two problems;
1) I cannot seem to get the speedometer to work. Apparently the 91's didn't have the vss buffer box, I've tried wiring the speedo output from the Fitech directly to the speedo cluster input wire.. Still nothing, has anyone on here had any experience with this system on a 91 Camaro ?
2) I connected the tach output wire to the white wire coming into the dash connector and it doesn't work either...
Fitech is absolutely no help with this...
I have one in my 92. The tach works fine for me but that's because the ecm has nothing to do with it. Wire straight from the coil to D6 on the C100 sends it to the tach.
I have no direct solution for the speedo. My problem is the same, hooked it up, it does nothing. My car formerly had a buffer box, I may need to reinstall that or get a Dakota Digital box. My other issue is the interface doesn't show my speed either. So maybe it has a failure or wire issue. It's not my vss since it worked before the swap. I haven't gotten back into the garage this spring but if I find the solution, I'll post it here.
Oh interesting, I thought the non-buffer VSS setups were only in the V6s! If your car did indeed come without a buffer box, then the VSS signal would have been processed and sent to your gauge via the ECU. If you had to pull the factory ECU out for the FiTech install, then your gauge wouldn't be getting the right signal anymore. Dakota Digital box is probably going to be your best bet.
Not surprised to hear FiTech won't help, a friend of mine has been having pretty similar issues trying to get FiTech to work on their 383 TPI motor over the last year or so, customer service has been pretty much useless.... from what I hear, they automatically assume it's for an LS, doesn't seem like many (if any) of the techs are familiar with TPI
Oh interesting, I thought the non-buffer VSS setups were only in the V6s! If your car did indeed come without a buffer box, then the VSS signal would have been processed and sent to your gauge via the ECU. If you had to pull the factory ECU out for the FiTech install, then your gauge wouldn't be getting the right signal anymore. Dakota Digital box is probably going to be your best bet.
Not surprised to hear FiTech won't help, a friend of mine has been having pretty similar issues trying to get FiTech to work on their 383 TPI motor over the last year or so, customer service has been pretty much useless.... from what I hear, they automatically assume it's for an LS, doesn't seem like many (if any) of the techs are familiar with TPI
3.1L and 90-92 tpi has a Vss buffer it’s not an external box but incorporated in the 1227730 ecm unlike tbi that uses a buffer box and i think 88-89 tpi maf as well .
3.1L and 90-92 tpi has a Vss buffer it’s not an external box but incorporated in the 1227730 ecm unlike tbi that uses a buffer box and i think 88-89 tpi maf as well .
Interesting! I knew about the 3.1 since I recently tuned the Road Speed Constant/ IP Pulse Divider for my trans swap, but I wasn't aware about the 90s '7730 TPIs using this feature as well. Pretty cool!
Thanks for the info, the tach is back .. The speedo works on my interface... Guess I'm gonna need the Dakota digital box to get it to work, I plugged the old vss wires into the transmission and nothing... Thanks for the help...
I hooked mine up to a '92 K2500 so my experience is a little different but I had these problems. Changing the 'from cal' settings to 'On' and 'fromcal' allowed me to get outputs on the wires, and my Speedometer started working. I think I had the FiTech output going straight into the speedometer and not through the factory converter box thing that the vss originally went to.
Tech support helped me with the above but they gave up on me with the tach output from the ecm. I ended up wiring the white wire off the coil straight to the tach and it worked just fine.
My Dakota digital box is on it's way... Anyone used one of these to make your speedometer read correctly on a Camaro? Could save a bunch of time if I had the setting I needed... Thanks
My Dakota digital box is on it's way... Anyone used one of these to make your speedometer read correctly on a Camaro? Could save a bunch of time if I had the setting I needed... Thanks
It's been a while, like three years, since I tinkered with it but you give the box switched power (I took it from the stereo cluster since I have no stereo), a signal from the VSS, ground and then the speedo cable from the stock harness to one of the 5 outputs. The outputs differ in the pulses they send. Find the one working and being closest and then you can offset it to be correct.
If you bought the SGI 100BT like I have you connect it through bluetooth and tune it from your phone (with the Dakota Digital app). It's doable from the device itself but waaaaay more of a hassle compared the phone.
