Chalks_21 Posted February 28, 2023 Report Share Posted February 28, 2023 Hey all, I’m currently trying to figure out a tacho boost issue on my 1990 mx83 series 2 Cressida, 1jz non vvti running a Link Stormx ECU. It seems like the tach isn’t receiving signal from the ECU and doesn’t tach sweep when ignition is on. I’ve confirmed continuity from pin out wire to brown 12pin dash plug. Confirmed booster relay has switched 12v power and has earth. Confirmed booster relay is pinned to Aux 1. Confirmed Aux1 is set to tacho and is reading “active” when car is running. Confirmed power, earth, sig in and out are connected to the correct pins on relay. tried a completely different dash.. Even tried PWM test and adjusted duty cycle to try get the tacho to move but no luck was had. The only thing left is to check with a new relay and or try different settings in the software itself, If anyone has had a similar issue OR has certain settings set for the tach plz let me know ❤️ Been dicking around trying to figure it out for a while.. also happy to add my ECU Map if it’s needed. Quote Link to comment Share on other sites More sharing options...
Adamw Posted February 28, 2023 Report Share Posted February 28, 2023 When you say "booster relay", do you have a commercially available product or something DIY? Quote Link to comment Share on other sites More sharing options...
koracing Posted February 28, 2023 Report Share Posted February 28, 2023 I would think like the MSD 8920 or Widget man tach signal booster. Since it looks like a relay and is called a "booster" in the description, but clarification would be useful. It does mention in the directions if it's hooked up wrong it can become damaged, however. https://www.ebay.com/itm/142171581596?epid=3012319916&hash=item211a162c9c:g:OtMAAOSwKTheuX-Q Quote Link to comment Share on other sites More sharing options...
Chalks_21 Posted February 28, 2023 Author Report Share Posted February 28, 2023 11 hours ago, Adamw said: When you say "booster relay", do you have a commercially available product or something DIY? Commercial product, looks just like a relay with modified internals Quote Link to comment Share on other sites More sharing options...
Adamw Posted February 28, 2023 Report Share Posted February 28, 2023 Ok, if it is a commercially available product I would expect there is a transistor inside that so the aux output flywheel diode doesn't clamp the flyback but possibly not. Can you try moving your signal wire to one of the spare injector drives instead of Aux 1 and set the tacho function to that output. Quote Link to comment Share on other sites More sharing options...
Chalks_21 Posted February 28, 2023 Author Report Share Posted February 28, 2023 13 minutes ago, Adamw said: Ok, if it is a commercially available product I would expect there is a transistor inside that so the aux output flywheel diode doesn't clamp the flyback but possibly not. Can you try moving your signal wire to one of the spare injector drives instead of Aux 1 and set the tacho function to that output. Will give it a go when I get the chance definitely Quote Link to comment Share on other sites More sharing options...
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