volare79

I recently just swapped out the lean burn system and heads on my 79 volare, the problem is the engine will not stay running when the key is in the on position, it runs when its cranking. I'm not getting voltage at the +coil either when its on run, I checked at the ballist too, no voltage from the terminal that has the +coil wire going either, I get battery voltage on the run side of the ballist where the wire from the ign module and run are. Both my run and start wires have battery voltage, I ran my run wire from the DLC or dignostic connector to the left side of the ballist(also thats where the blu/yel wirefrom the module splices in) and my start wire is coming from the starter relay to the right side of the ballist where it splices in to the wire that goes to the coil+. I made sure my black/yellow wire from the ignition module to coil- is also hooked up. I'm not sure if my run voltage wire is back feeding threw the resistor to the stater relay somehow? I removed the the starter circuit completely and did a voltage test from the battery ground to the right side of the terminal on the ballist when the key was in the run position(run terminal was hooked up) and I had battery voltage. Any help would be appreciated.
Jon

volare79

I re traced the wires, ohmed out the wires, I just can't figure it out. Only thing I can think of is does the ECU have to be grounded, I have it bolted to the inner fender. I just can't understand were I'm loosing my RUN voltage which should be 7 to 8 volts, if I ran a jumper wire from the battery to the coil+ for a few seconds would that short out my ecu?
Thanks for the help.

richinny

yes, the ecu should be grounded.

volare79

I jumped battery voltage to the coil and it fired right up, still haven't figured it out yet.

volare79

I got it running now with 7 volts at the coil, I'm not sure if its right though, here's a diagram I have been following(many diagrams are the same way). http://www.oldengine.org/unfaq/leadfoot/e-ign1.gif

I elimnated the brown wire from the coil+ to 12v start, my dmm reads 7volts now from battery ground to coil+ , I was testing around with dmm and I was losing voltage at that start wire or it was grounding to the relay somehow. So since I took out that brown wire I'm assuming my 12volts at starting are gone? Will this be an issue? I will test that tommarrow when I am able to get another set of hands to help me.

richinny

did you have a ballast resistor with one two or 4 wires on it? it came with the 4 pin type.

does the ecu have 4 or 6 pins?

that brown wire does not go to the starter relay.

you need two hot feeds to the ecu.

one lead feeds power when the switch is on. it is connected to the wire on the ecu. the other feeds power from the ignition switch when it is in the start position.

on the 4 pin resistor, one side of the pins provides 12v while cranking. the other pin provides the reduced voltage when running.

be careful as the resistor gets so hot it will blister you hand before you can pull it away. buy a second resistor and keep it in the glove box.

that diagram does not look right to me.

volare79

The mopar kit I purchased has a 4 pin and a 2 pin resistor, I figured it out, it doesn't matter what wire I use in the engine compartment for 12v start, the 12v run will feed back through the resistor then make its way to the starter. Using a diode in series the brown 12v start wire will prevent this feed back to the starter and make it for a clean wiring job.
Thanks everyone for the help.

richinny

no need for the diode.

that module only has one power line in. the run position of the ignition switch gives you power with the key on. when you turn it to start the start wire should be wired to bypass the ignition resistor when cranking.

run--->>>>>>>>>>>>>)------<resistor>-----ECU
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start--->>>>>>>>>>>>>>>>>>>>>>>>