no spark in start

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With the dist installed and the cap off does the rotor turn when you crank the engine?
 
You could get another battery and power the coil and the ECU from that. Jumper the negitave side if the stand alone battery to the body or block. Disconnect the feed to ecu from ballast resistor. Disconnect the coil plus wire.
Attach the plus side of the stand alone battery to the feed of the ECU and coil plus

You now have a dedicated power source to run the electronics, no voltage drop during cranking.
 
yes, rotor turn when cranking and the correct coil from FBO.
Did some more checking today.
The yellow wire from ignition switch unplug from the relay box on the apron I get 12 volts in start out the wire.
So with the yellow ignition wire unplugged from the relay box, in start I get 11.5 volts at the coil. so everything seems to work right bypassing the starter.
Could the starter be drawing more voltage now for some reason? Pulled starter out of the block but still connected checking for shorts, in start I still get 11.5 to coil. I put the starter back in the block and in start it back to 8 volts when the starter is under a load.
Bad mini starter, anyone seen this before?
 
If the voltage during cranking at the ig sw is not within 1/2 volt of battery voltage, then some voltage is getting lost between them. The usual culprits, in order of probability are: the firewall connector, the fusible link, or the ammeter gauge.
The most voltage you can get at the switch is battery voltage.
So if it's less than 9.5 volts at the sw,(and therefore just a tic less than that at the battery), and the aforementioned connections are good, then the battery is either in need of charging, or dead, or shot; or the starter is drawing way too much current, making the battery appear to be shot..
 
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If the voltage during cranking at the ig sw is not within 1/2 volt of battery voltage, then some voltage is getting lost between them. The usual culprits, in order of probability are: the firewall connector, the fusible link, or the ammeter gauge.
The most voltage you can get at the switch is battery voltage.
So if it's less than 9.5 volts at the sw,(and therefore just a tic more than that at the battery), and the aforementioned connections are good, then the battery is is either in need of charging, or dead, or shot; or the starter is drawing way too much current, making the battery appear to be shot..
I swapped out the starter and battery, same results.
 
Well, someone already mentioned to bypass all of the ignition system, by jumpering the battery directly to the FBO ECU. So if you can't get within 1/2 volt of battery voltage there during cranking using this method, then disable the ignition system, charge the battery, and try again. If the battery voltage is still low, then take out the plugs, charge the battery,and try again. There has to be a legitimate reason that the battery is falling to 9.5, and since you already subbed in a different battery, and a different starter, then it sorta has to be mechanical; like liquid in the cylinders,over-advanced ignition, or dragging internal parts, just to name the most likely.
 
Well, someone already mentioned to bypass all of the ignition system, by jumpering the battery directly to the FBO ECU. So if you can't get within 1/2 volt of battery voltage there during cranking using this method, then disable the ignition system, charge the battery, and try again. If the battery voltage is still low, then take out the plugs, charge the battery,and try again. There has to be a legitimate reason that the battery is falling to 9.5, and since you already subbed in a different battery, and a different starter, then it sorta has to be mechanical; like liquid in the cylinders,over-advanced ignition, or dragging internal parts, just to name the most likely.
Yep that’s what i plan on checking next. Pull the plugs and spin it over be hand and see how freely it spins. The plugs did sit out of the motor for about two weeks, maybe some rust?
 
Well, someone already mentioned to bypass all of the ignition system, by jumpering the battery directly to the FBO ECU. So if you can't get within 1/2 volt of battery voltage there during cranking using this method, then disable the ignition system, charge the battery, and try again. If the battery voltage is still low, then take out the plugs, charge the battery,and try again. There has to be a legitimate reason that the battery is falling to 9.5, and since you already subbed in a different battery, and a different starter, then it sorta has to be mechanical; like liquid in the cylinders,over-advanced ignition, or dragging internal parts, just to name the most likely.
Ok removed the plugs and spun the motor by hand, turns freely no drag.
With the plugs removed, 12 volts at coil in run, 8.7 volts in start and has spark from plug.
Reinstall plugs and voltage back to 8 in start and no spark. So with and without plugs I'm only loosing .7 volts from cranking motor, I think that is what I should expect. So why do I only have 8.7 volts in start with plugs remove, I would think I should have some where near 10 volts. yes no?
 
I should have some where near 10 volts. yes no?
Yes but cranking voltage at the battery with all plugs in,at summer-time temperature, should be more than 10.5v and holding for at least 15 to 30 seconds at this time of year. The longer it holds the bigger or the better, or the stronger, is the battery.
Prove your gauge is telling the truth. If good
Carbon-pile test the battery. If good
I'd say test the starter but I know of no better test than bolted to the motor and sucking electrons, as it now is doing. So then I'd suggest
Replace that ECU with it's high minimum-voltage requirement.
 
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Current takes the path of least resistance. In start that would be the large battery cable to starter and the starter. Everything else about the car runs on different much smaller wire. Then there's a fusible link, amp gauge, ign' switch, bulkhead terminals, etc.., to create more resistance in this path. What you have found thus far, you have less than battery voltage through all of that stuff, and lesser still when starter is drawing the lions share. There always was a back feed through the ballast resistor during start but that resistor reduced the backfeed/draw. A bypassed ballast resistor doesn't. I would need to study wiring diagrams for your model to know what circuits are getting full 12 volts during start that should not.
Relays are used to get improved voltage to headlights. Same approach would get improved voltage to charging and ignition systems.
 
Current takes the path of least resistance. In start that would be the large battery cable to starter and the starter. Everything else about the car runs on different much smaller wire. Then there's a fusible link, amp gauge, ign' switch, bulkhead terminals, etc.., to create more resistance in this path. What you have found thus far, you have less than battery voltage through all of that stuff, and lesser still when starter is drawing the lions share. There always was a back feed through the ballast resistor during start but that resistor reduced the backfeed/draw. A bypassed ballast resistor doesn't. I would need to study wiring diagrams for your model to know what circuits are getting full 12 volts during start that should not.
Relays are used to get improved voltage to headlights. Same approach would get improved voltage to charging and ignition systems.
Ok, I removed the jumper wire from the ballast resistor and now have spark and it started.
 
I can't know exactly where your current loss is. I know some of it is inherent. OEM wiring was barely adequate for the OEM equipment. Later models with upgraded OEM equipment have upgrades in their wiring, ign' switch, etc. Anyway...
A relay would cure it. Ign.1 and ign.2, the brown and blue, tied together would do nothing more than signal/close the relay. Added wire with fusible link from starter relay stud routed to and through the relay when its closed to feed ignition system, charging system, electric choke if present, maybe even electric fuel pump on same relay. Common bosch relay is rated at 30 amps.
 
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