street fire cd on 1974 chrysler 70hp 3 cylinder dies after 30 seconds

christo555

Seaman Apprentice
Joined
Aug 12, 2010
Messages
49
my 1974 chrysler 70hp 3 cylinder starts easy but runs only about 30 seconds and dies. if i turn the ignition off, it will restart easy and again run for 30 seconds and die. i can repeat this test forever.
the confusing part of this test is that if i just turn the ignition switch to crank/start the engine without FIRST turning off the ignition , i have found that it won't start because there is no spark at the plugs.
i installed the street fire cd because of the die in 30 second problem, but the new unit does the same thing.
are both cd units bad??? is there some kind of kill engine device that is operating after 30 seconds or so??
i'm assuming i have some kind of spark/electrical problem here as it always restarts instantly after dying, as long as i turn off the ignition BEFORE trying to restart.
thanks for any help anyone can give me. i'm stumped.
christo555
ps: does this engine use solid core ignition wires?? the street fire cd unit can't be used with solid core wires.
 

Frank Acampora

Supreme Mariner
Joined
Jan 19, 2007
Messages
12,004
Re: street fire cd on 1974 chrysler 70hp 3 cylinder dies after 30 seconds

Yes, it uses solid stranded core wires. Let me think a while about the stalling. Could be a bad ignition switch or a loose connection at the engione terminal board. Check the red wires, especially the red and blue ones that go up under the flywheel to power the CD box.
 

christo555

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Aug 12, 2010
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49
Re: street fire cd on 1974 chrysler 70hp 3 cylinder dies after 30 seconds

frank,
thanks for the reply. i was hoping you might be interested in my problem.
when i installed the new street fire cd unit, i installed new wire from terminal block to the new cd unit, and i have checked those connections a couple of times. on the ignition switch, i used a jumper wire from the red 12volt terminal to the blue ignition terminal on the switch. i was hoping that the engine vibration of the switch was making it intermittent. but, no luck, was till dying.
i also tried disconnecting the distributor drive belt and used a drill to rotate the distributor with the ignition on and the engine flywheel turned to where the #1 cylinder is firing and the spark plug wire for #1 connected to an external test plug so i could see if i was getting spark for more than 30 seconds.
and guess what happened?
i was getting spark!
and for way more than 30 seconds. i tested it for like 5 minutes with good spark the whole time.

i am baffled. because i read that the street fire cd can't be used with solid core wire because of the extreme amount of radio frequency interference(rfi) that is produced and which interferes with the electronics in the street fire cd, i thought the test i just did would result in the cd failing to make spark after 30 seconds.
now i have to imagine that the rfi produced when the engine is running is different from the test rfi produced with an exposed spark plug.
this problem is a real challenge for me and i am losing, so far.
thanks again for any help, christo555
 

christo555

Seaman Apprentice
Joined
Aug 12, 2010
Messages
49
Re: street fire cd on 1974 chrysler 70hp 3 cylinder dies after 30 seconds

well, i'm biting the bullet and buying another cd unit, this one by cdi company.
i will post on what happens after i install it this week.
 

christo555

Seaman Apprentice
Joined
Aug 12, 2010
Messages
49
Re: street fire cd on 1974 chrysler 70hp 3 cylinder dies after 30 seconds

well, the new cdi unit fixed the problem. the motor starts easy and runs great now. i think i destroyed the original cd unit and the streetfire cd unit by dry firing(coil sparking with no spark plug or tester connected to the coil) them while i was working on timing or other tests i was doing.
happy now!!!
thanks again for all the help from you guys.
 
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