Join Date: May 2010
Location: Williamsburg, VA
Wannabejeeper asked earlier in thread, so I sent him the following PM
I didn't want to hijack the thread so I figured I would send you a pm. I used what is commonly referred to on the forum as a junkyard tbi. Essentially I put together a throttle body injection system using the parts from a gm mid 80's to early 90's 4.3L V6 engine (literally 10s of millions of them out there). I scavenged the ecm, wiring harness, throttle body, knock sensor control and some relays. I purchased a fuel pump, gm ignition module, knock sensor, speed sensor used the map sensor off my own jeep. I rebuilt the throttle body and cleaned it up, modified my distributor so the ecm could control my spark, modified the wiring harness to remove the wires not needed and shorten up those that were too long and installed everything. It runs great. I've chosen for now not to get a custom chip tuned for my engine as the run tables look pretty good and I'm happy with the performance. I followed a few how to guides on the web to put it all together. Howell sells a kit using the same throttle body, injectors, sensor and ecm, but doesn't use spark control in their kit and charges $1400 for it. I spent about $400 and have a system that controls both spark and fuel.
Howell and others make a good product and market their services. What you get from buying their kit is a single source, stickers and testing from EPA if needed (California folks have to have that) and some product service for questions during and after install.
What you don't get is a system that controls both SPARK and FUEL. Howell, for whatever reason, does not use the spark control feature in the ecm and does fuel only. If you have an aftermarket distributor and currently have issues with timing, you will have the same issues when you put on the Howell system. I venture to guess that most folks who throw on a carburetor don't go through the steps necessary to set their timing correctly, as setting timing is not simply advance at idle it involves spark over the entire power curve (which has to be coordinated with fuel delivery), something most never bother to address.
If you put together a system yourself you will use the identical items Howell uses for the ECM, wiring harness, sensors, throttle body, fuel pump, and injectors. You can, if you choose, add on a knock sensor and velocity speed sensor to give you better control, and of course you should take advantage of the ECM's ability to control spark timing which means you will add an ignition module controlled through the ECM. If you do that, you will have a better system than you would get for one third the cost from of the kit from Howell.
If you want to pursue doing a tbi install send me a pm. It isn't all that complicated and there are substantial resources already out there to guide you step by step.