TBI Wiring Harness | Affordable Fuel Injection This is a basic TBI harness for all engines using ECM 1227747 and 1228746 type ECM-many others can be used. Basic connections are standard but it is easy to customize one for your needs. Typically, technical support is limited to the customer with only a harness purchase due to the complexity of variables we have no control over. PAINLESS TBI HARNESS | eBay Save PAINLESS TBI HARNESS to get e-mail alerts and updates on your eBay Feed. + Items in search results. See search results that fit your vehicle. 1 product rating - Painless Wiring 60101 GM TBI Fuel Injection Harness. $495. or Best Offer. Free Shipping. 30 new & refurbished from $417.