need help asap please.car olny sparks when turn key off

Posted By: toplescuda

need help asap please.car olny sparks when turn key off - 12/26/08 11:57 PM

buddy has a 71 charger that ran fine with the factory points (small block) then one day his wife drove it to work and came out ..nothen so brung it home thinking the points burnt up so now is good time to upgrade to eletronic. so bought a conversion droped it in still no start so bought a new coil still no start
got a couple of differnt digrams and evert thing is hooked up right but the only time it will spark is when you turn the key off and its just a one time spark till next time turn it off
have a 73 car that runs fine and checked the power to both sides of the coil both with key in run and start and the exact as the one that wont run so what the heck is the deal box is grounded even swaped the box off the running car still nothen why is it only getting a spark from the coil when turn the key off thanks in advance guys

Posted By: Andrewh

Re: need help asap please.car olny sparks when turn key off - 12/27/08 12:03 AM

Little jumbled.
Let me get this straight.
The car has no spark when cranking.
You replaced everything but the ballast resistor.

You now have electronic ignition.

You see a spark when you turn the key off, but at no other time.

You get voltage to the coil in run and start.
What voltage do you get?
12 volts in both places?
Bad ballast, but the car should start and die when you let go of the key.

Posted By: JeffC

Re: need help asap please.car olny sparks when turn key off - 12/27/08 12:03 AM

maybe ballast resistor or ignition switch. will it fire if you jump the starter relay?

Posted By: toplescuda

Re: need help asap please.car olny sparks when turn key off - 12/27/08 12:12 AM

car cranks over fine and the ballist is good it just dont spark from any time you turn the key on(even cranking) till you turn the key to the off postion then it has one nice spark

Posted By: Andrewh

Re: need help asap please.car olny sparks when turn key off - 12/27/08 12:18 AM

eliminate the key and hot wire it.
Put a 12 volt positive to the coil and hit the relay so it turns over and see if it starts.

Nothing else in the circuit really.

Posted By: groundpoint6

Re: need help asap please.car olny sparks when turn key off - 12/27/08 12:24 AM

Sounds like a bad distributor pick up coil

Posted By: mopar_man

Re: need help asap please.car olny sparks when turn key off - 12/27/08 01:02 AM

The box is gone !! Sorry reread your first post , As the above poster said , looks like the pick up coil in the dist is not working or the gap is too wide to trip the ECM which in turn unloads the coil

Posted By: spl151

Re: need help asap please.car olny sparks when turn key - 12/27/08 01:37 AM

Quote:

The box is gone !! Sorry reread your first post , As the above poster said , looks like the pick up coil in the dist is not working or the gap is too wide to trip the ECM which in turn unloads the coil

Yep thats the problem had it happen to me!

Posted By: IronWolf

Re: need help asap please.car olny sparks when turn key off - 12/27/08 01:59 AM

Check to see if the coil wire is not seated properly on coil or distributor (audible click).

If that's not the fix, check connections to the starter relay - those wires from the Neutral Safety Switch and ignition switch (yellow wire) aren't too weather-tight.

Posted By: RapidRobert

Re: need help asap please.car olny sparks when turn key off - 12/27/08 02:16 AM

set the reluctor gap to .008". key on coil wire 1/4" from ground & jump coil neg to ground & make & break it. if the 73 is a SB borrow it's dist

Posted By: NITROUSN

Re: need help asap please.car olny sparks when turn key off - 12/27/08 02:23 AM

Quote:

then one day his wife drove it to work and came out ..nothen so brung it home thinking the points burnt up so now is good time to upgrade to eletronic. so bought a conversion droped it in still no start so bought a new coil still no start

You most likely could be fighting the original problem. The car did not run with points so maybe the problem is in the ignition switch or wiring. It may not have anything to do with the conversion.

Posted By: AdventurerSport

Re: need help asap please.car olny sparks when turn key off - 12/27/08 02:27 AM

Quote:

Quote:

then one day his wife drove it to work and came out ..nothen so brung it home thinking the points burnt up so now is good time to upgrade to eletronic. so bought a conversion droped it in still no start so bought a new coil still no start

You most likely could be fighting the original problem. The car did not run with points so maybe the problem is in the ignition switch or wiring. It may not have anything to do with the conversion.

bad idea to assume the points were bad and do a conversion without confirming the original problem, because now you don't really know what the original problem was...

start there, and good luck!

JS

Posted By: groundpoint6

Re: need help asap please.car olny sparks when turn key off - 12/27/08 02:54 AM

Dist pick up coils are a/c generators. Set your DVOM to an A/C voltage low scale and hook the leads up to the pick up coil. Crank the engine, if you get any reading at all the pick up coil is good, if not change it

Posted By: JonC

Re: need help asap please.car olny sparks when turn key off - 12/27/08 02:55 AM

I had this problem when I converted to electronic ignition. In my case, I wired the ballast reistor wrong. Mine was trying to start with the resistor in the cicuit, the starter was drawing enough power to prevent the ignition from getting enough power to ignite. It turned out that I had the bypass for starting on the wrong side of the resister. Just a thought.

Posted By: cjskotni

Re: need help asap please.car olny sparks when turn key off - 12/27/08 03:21 AM

I had the exact same symptoms when my brand-new ECU box died...stupid Mopar Orange ECU!! You would get no spark when you cranked the motor until you turned the key back then one nice spark...

Other than that check the grounds on your ECU and voltage regulator with a continuity meter...

Posted By: bigblock4x4

Re: need help asap please.car olny sparks when turn key off - 12/27/08 04:14 AM

the ignition box was bad on my truck,it did the same thing bought msd

Posted By: sthemi

Re: need help asap please.car olny sparks when turn key off - 12/27/08 06:11 AM

My add to this problem is that I had a bad wire in the ignition harness where it plugged in to the the switch.
Another possible problem is a bad connector in the firewall bulkhead connector for the ignition run switch.

Also the ignition switch itself could be bad.

Posted By: 71_deputy

Re: need help asap please.car olny sparks when turn key off - 12/27/08 02:04 PM

Quote:

My add to this problem is that I had a bad wire in the ignition harness where it plugged in to the the switch.
Another possible problem is a bad connector in the firewall bulkhead connector for the ignition run switch.

Also the ignition switch itself could be bad.

i agree- the orginal problem- as you turn off the ing. key there is enough connection to give spark!

Posted By: stumpy

Re: need help asap please.car olny sparks when turn key off - 12/27/08 03:42 PM

Get your test light or VOM out and start doing some diagnosing. Check to see if you have power to the +coil terminal with the key in the runpostion. if you do then jump the starter relay on the fender to crank the engine and see if it starts. If it does then you need to see if you have power to the coil while holding the key in the start position. If you have power there then it's not an ignition or bulkhead wiring problem.