I have been PM’ing and talking to techs trying to determine the performance issue on an LT1. At this point any thoughts would be appreciated. Let me give you a brief history. The boat was not winterized and resulted in a cracked block. On top of that, I'm following a mechanic that changed parts with the wrong ones. A running LT1 was obtained to install in the boat. When the installation was complete the engine started, however, when you accelerate quickly it pops into the intake, if you slowly accelerate it starts to pop into the intake around 2500 rpm. Checked compression and it's 220-225psi on each cylinder. Checked each plug wire to see that it was firing with a timing light. The plugs appeared to be burning lean when I started, fuel was clearly an issue too. Fuel pressure was 25psi key on, engine off, lower running. I replaced the (TBI max 25psi) fuel pump with the correct fuel pump, now I have 47psi key on engine off and 3
si running. I removed cleaned and tested all 8 injectors, they are all functioning properly. The TPS and coolant sensors have both been bench tested and function. The fuel pressure regulator is functioning as it should and there are no volume issues. I ran the engine up to 2500 where it starts to pop into the intake, I then used a propane enrichment bottle to see if I had a lean condition, again little to no change. My final thought, I have contacted a few friends trying to locate someone in the Williamsburg/Richmond area that can custom program MEFI computers. I have seen a few of these problems on the forum however, I couldn’t seem to find the fix posted. Thanks in advance for any help.