Suddenly no spark...

'79 Dk. Green · 08-30-2009, 11:20 PM

not when I was driving it, but overnight. Last Saturday I was out of town and parked at Hotel @6 pm. At @6 am, I started it and it would not fire. I heard fuel pump prime after a bit. I had a co-worker check the coil wire held close to a ground and there was no spark coming from element with start. Late to work, I decided to try again at lunch. I went to parts store, got a coil (likely wrong kind since it was for 1970 chevy v-8?) and an idiot light. With the light I found both + and - side of small coil wires light it up with ignition and start. Swapping coil did nothing. The green wire seems to be okay, but is old. Timing belt/water pump was changed last year with new cold start valve. Belt turns rotor fine. I cleaned the contacts on the rotor and cap, still nothing. Because of aftermarket alarm (ungo siren still in nose of car) I unhooked the battery for a few minutes, and no fix. It is a 1979, and besides owners guide showing fuses and relays, I am not sure where any ignition relays or fuses are located. Seems the coil isn't getting signal? Car is there, so I either have to fix it there, or arrange a 80 mile tow. Thanks!

vdubr928 · 08-31-2009, 02:12 AM

Check for power at the coil. In other words get a chassis ground turn the key on and check for 12v+ to the coil. You alarm will interupt this if it is faulty. Green wire provides the ground (via spark box on pass fender) so if you have voltage then you have to look there.

DPW928 · DPW928's Garage

When cranking you should have 6 to 9 volts at the 15 post of the coil. If less than 6 volts, clean the connections on the resistors at the panel in front of the left fender well. If that is OK, check the pump fuse for corrosion, pull the fuel pump relay and clean the contacts and check/clean the contacts of the green wire where it plugs into a female connector at the right side fender well.

Mrmerlin · 08-31-2009, 08:21 AM

check the 14 pin connector at the jump post

MPDano · MPDano's Garage

Quote:

Originally Posted by Mrmerlin

check the 14 pin connector at the jump post

This is what I was going to suggest last night but didn't know the exact count on the pins, so I didn't want to confuse you. Separate the connector and clean the posts. There is also a cap on that connector, remove it carefully and clean and check for solder breaks. I am betting on Merlins suggestion.

'79 Dk. Green · 08-31-2009, 06:05 PM

Thanks guys for the information. I will bring a meter to check + voltage rating, clean the two ballasts, and will clean-check the 14 pin connector when I can, and let you know my findings.

Mrmerlin · 09-01-2009, 08:02 AM

disconnect the battery B4 working on the hot post

'79 Dk. Green · 09-13-2009, 10:43 PM

Hello again fellow Sharksters. I was down with the car again this weekend and tried the good suggestions you all replied with. I brought a multimeter and first checked the coil wire at the 15 side and at cranking, it read 11.4.
I carefully removed the pin connector cover on right fender behind the jump lug, and got a moment of excitement when I found the rearmost (closest to engine) wire (green with dark stripe?) corroded and separated from the pin. I stripped @ 1/2 inch of the insulation, cleaned the exposed wire and captured it between the pin-socket, but it made no difference. What is that wire for? I did look at the other pins and yes, the black wire does start the car!
Again, there is no spark from the coil to the plugs, the fuel pump seems fine, it primes system every so often. All looks good except no spark...
I will be arranging a tow so I can start to "get into it" more than in a public parking lot. Any other ideas? Where does the ignition system go in a '79 that I can follow? Thanks again.

DPW928 · DPW928's Garage

The next step would be to ohm test the coil to see if it is bad. Also, have you checked the connections on the green wire that runs from the distributor to a connector near the ingnition module?

'79 Dk. Green · 09-23-2009, 02:05 PM

Hello again-I got the car towed home (70+ miles) so can now work on it better than in a public parking lot. I tried suggestions given, except since I still have a multimeter, want to test the "green wire" with it. what is the best way? What setting do I put the meter on? The green wire is disconnected from fender side, but still on distributor. If I need to disconnect it from distributor, do I remove the metal part? (looks like a retainer).
Also, still curious what the aft most wire in the pin connector (at remote jump lug rt. fender) I fixed is for?

Thanks again!

DPW928 · DPW928's Garage

To disconnect it from the distributor you will need to remove the screw underneath the metal retainer. Initially I would check the connector at the fender to make sure there is no corrosion. To check the wire itself, use your multimeter to check for continuity on each of the wires then check to make sure there is no leakage between the wires.