Opti Spark and Fuel

[Mciamp99]

I am having a tough time making this connection. I have placed a lt-4 froma 96 Vette into my wifes 1975 Vette. It looks great. Only porblem is it wont run. To make a long story as short as possible. VATS is programmed out of computer as is AIR and several other things. I show no codes on the scanner. Fuel Pressure is 48 psi, yet the fuel injectors wont fire. They have power but will not pulsate. They are also not gummed up as they will fire if I ground them out and the motor will fire on any hint of fuel and appears to run on all 8 cylinders.

It has been suggested that the opti spark may be bad and not sending the low res signal to fire the fuel injectors. There is spark at the plugs. I am having a tough time convincing myself that a bad Opti Spark Distributor would stop the flow of fuel into the motor. Please help me and my feable mind make this connection. I would be interested to hear the thoughts of the readers before I spend the money on a new distributor.

P.S. My wife is now very unhappy that her beloved corvette that should have been junked before I started this project no longer runs. When it does work, I know she will be oh so greatful and I may get back into the big bed.

[compyelc4]

Simply put....the Opti is THE main source of signal pulse for your injectors. It reads the cam position in the Opti, and, using reference "reads" from two different slotted disks in the Opti (one fuel, the other fire), sends those signals to the ECM for the brain matter to do the fuel and spark.

[Mciamp99]

Thank you for the input, no one else has been able to help me make that connection. I hope to be running by the end of the week

[Trance_LT4]

I'm curious as to how you deprogrammed the AIR from your computer, as to not have trouble codes. I'm running headers that don't have an AIR input, so I'm not using the system, but I keep tripping codes.

[Mciamp99]

I sent the computer to Corvette Clinic in FLA and Chris Petris took care of the computer reprogramming. He has been a great help to me throughout my whole project.