Hello Not sure if this is posted in the right place but here goes My 70 gs 455 is ready to fire up. I had the engine rebuilt and dynoed. After the dyno it ran on a stand for one hous to make sure no leaks. So this engine is tuned and timed. I dropped it in the car and hooked everything up. All fluids are in. I cranked it a few times until I saw gas squirting in when the throttle was engaged so I know it’s getting gas. I turned it over and it fires up for a second and shuts off. I tried this several times with the same results. It’s getting gas and the gas is igniting but it won’t stay running. Many of you are old school experts with these engines so I am asking for opinions on what could be the problem. Could it be something electrical not connected correctly? How can I step by step diagnose this. Thanks to all.
Does the engine turn off as soon as you let the ignition key go? Started wire connected correct? There the main power wire from the Battery and two small wire that get connect on either side.
I bought that harness from Lectric limited and hooked them up as they told me. If they were reversed that would cause the problem?
Turning over is seperate from coil voltage but it gets the full 12volts at cranking then drops to 7 volts.
Are you running points or electric conversion in your distributor? Some conversions require a full 12 volts at the coil all the time and don't use the resistive wire that connects with the factory setup. Also, what coil are you using?
Your original wiring looks correct. What you need to check is the the positive side of the coil. Are you using points still? The starter solenoid provides a direct 12 volts to the coil when cranking only. After you let go of the key, power flows to the coil from the firewall/engine harness. That is where you are losing voltage. You may have an extra connection at the coil + that you neglected to hook up. Check that. If not, back trace the wire that is connected to the coil + and see where it goes. It should run from the firewall to a point where it hooks together with the yellow solenoid wire. The resistance wire runs from the firewall to a point where it is joined with that yellow wire from the solenoid. That yellow wire jumps out the resistance wire when cranking ONLY. http://v8buick.com/index.php?thread...ystem-function-tests-and-modification.248990/
I am running points The coil is an nos one I bought that was tested ok. Coil has one side from the distributor and the other side is the harness. Negative side also has a wire coming from under the dash for the tach
None of that matters. It would not be the first time a new product was defective. It will only take a minute to connect a voltmeter between the + side of the coil and ground. Then turn the ignition on to RUN and read the meter. You will either see 12 volts, or 5.0-5.5 volts depending on whether the points are open or closed. If you see no volts, there is a wiring problem.
So yes with the key in run position I have zero volts at positive side of the coil So can you explain this voltage to me? The positive wire is in unison with the yellow wire on the starter?
Read the second paragraph in the thread I linked for you. (Click below) http://v8buick.com/index.php?thread...ystem-function-tests-and-modification.248990/
