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My current coil seemed a little crispy although was running alright so I decided I could probably change it. I ordered two Delco coils and they both produced the same problem. Once installed and the car turned on, the digital dash and AC controls began rapidly flashing along with the speedometer reading it was going 80 miles an hour while standing still. The coil was also making a rapid ticking noise - the first replacement I installed had a couple burn marks on the wiring where I assumed it was arcing. But the second replacement didn't have those marks but exhibited the same strange behavior. Once I replaced the original coil, all the flickering and sparking stopped. Below is a comparative picture of the two coils with the original on the right. I noticed the original that works ok has exposed areas of wiring that don't seem to be a problem and the red and white wires are actually crossed right where they exit the potting material. Has anyone encountered this issue and if so, any thoughts on what may be causing it? Two Delco Coils in a row from Rock Auto have done it!
If you didn't swap out the cap and rotor while you were swapping out the coil, maybe double check to make sure that strap is seated and screwed down properly and making full contact with the connector.
Natty, your feedback is quite helpful here but there is an interesting plot twist. I did not replace the cap or rotor, however upon closer inspection it appears that there is a ground strap that is of a different design than the replacement cap you pictured there. The exposed portions of the coil wires seem to make contact with it. The new coil did not have exposed portions of wire and therefore didn't make contact with the ground wire. See the picture below and see if you agree with this assessment.
Thank you very much Natty! Odd though that it has been running like this for so many years unbeknownst to the previous owner. And, it doesn't go haywire with the coil which is currently installed - only news ones. Well I will be ordering one!
Thank you very much Natty! Odd though that it has been running like this for so many years unbeknownst to the previous owner. And, it doesn't go haywire with the coil which is currently installed - only news ones. Well I will be ordering one!
Probably should give your cap and rotor a check, too. That thing was probably sparking like crazy in there without the ground strap. Can fry your ecm, too, I think.
An inspection of the inside of the whole distributor is probably in order just to be sure of what you have going on in there, if anything. It's not much to do...
Natty you are spot on again! The ground strap was missing - once I replaced it and the new coil it's running well again. The only remaining mystery is how it was running somewhat with the old coil in there. There are so many improperly done repairs in this car its mind boggling!
Make sure you remove some of the paint on the coil where the ground connects too.
Thank you I did this as well. I noticed that the old coil did not have paint around this frame area but the new one did. I scraped the paint where it contacts the ground wire and the ground strap.
Natty you are spot on again! The ground strap was missing - once I replaced it and the new coil it's running well again. The only remaining mystery is how it was running somewhat with the old coil in there. There are so many improperly done repairs in this car its mind boggling!
I was wondering about that myself. Seems like it would have been noticed a long time ago.
He just didn't swap it out from the old cap. I did the same as you expect it to come with it, I did same.
That was the likely mechanism by which it happened. I was wondering how it was unnoticed for all these years. I did observe that the coil that was installed in the car was badly burnt, maybe was so weak it wasn't causing the pulsation in the cluster. There was a receipt where the cluster was rebuilt a few years back, I wonder if the mechanic told the PO that it was the cluster but didn't occur to him to check the ground strap.
Fortunately I got it working so its on to the the leaky oil pan and tie rods ends..
Thank you I did this as well. I noticed that the old coil did not have paint around this frame area but the new one did. I scraped the paint where it contacts the ground wire and the ground strap.
New Delco Coil causing Malfunctions
YW
