The Stovebolt Site Forums The Shop Area Engine Shop TBI on a 1959 235

I'm not an expert on the fuel injection, but I might could see a problem if he were trying to use port injection. But with the TBI he is simply replacing the carb with another method to atomize the fuel. The droplets or vapor has to still travel the same path that carbureted (sp) fuel would have to take.

Since the TBI is basically dropping the fuel in much the same way a carb would I can't see why it shouldn't work as well as a carb would. Should work better if set up correctly.

Many times on a cold start the TBI units do idle up some while the engine warms and will settle down to the proper idle speed once the engine is warm. Much like an automatic choke on a carbureator. Also, even with the TBI set up it takes a few starts and drive cycles to allow the ecm to "learn" where the proper idle needs to be.

If he has the ALDL connector installed to hook a scanner up (not just a code reader) it would help to see what the data stream reads while the engine is warming up. Is the coolant temp sensor reading while cold about the same as the ambient temp? If he's getting a bad reading from it due to the sensor or wiring then that may account for some of the high idle.

It could be as simple as it needs to be ran long enough to actually warm up and perhaps driven a few times for the ecm to learn the new driving parameters.