msd7al-3 problem

flash · 09-25-2015, 10:54 PM

I have 0 retard chips in each retard slot.even took them out and put 4 more new ones in!

Tom Goldman · 09-26-2015, 05:57 PM

All 4 retard inputs must also be grounded besides having the zero pill in if the retard is not being used.
I'd check that ground .

flash · 09-26-2015, 11:45 PM

I just checked my wiring of the car.none of the 4 retards are grounded. wired car by K & R wiring diagram and it does not show that either.easy enough to do but how does this get missed? talked to MSD twice and they never mentioned it either.will try thay tomorrow.

flash · 09-27-2015, 07:50 PM

thanks for all the advice! just thought everybody would want a followup on what was the problem and what fixed it.I tried grounding all 4 retard terminals and that did not change anything.I reversed the 2 wires from crank trigger-greem & purple wires that go to -M & +M to reverse the polarity and "that fixed it" timing is dead on 35 degrees. but the question is this-what happened or caused this to happen? wired the car 2 years ago with a K & R wiring kit.and we have checked and changed timing several times and it was always right.then one day the car slows down and we start checking things and found this problem.will it happen again and have to switch them back? happy to have found the problem and fixed it so easy. thanks to everybody that chimed in with advice!

buzzinhalfdozen · 09-28-2015, 03:45 PM

Quote:

Originally Posted by flash

thanks for all the advice! just thought everybody would want a followup on what was the problem and what fixed it.I tried grounding all 4 retard terminals and that did not change anything.I reversed the 2 wires from crank trigger-greem & purple wires that go to -M & +M to reverse the polarity and "that fixed it" timing is dead on 35 degrees. but the question is this-what happened or caused this to happen? wired the car 2 years ago with a K & R wiring kit.and we have checked and changed timing several times and it was always right.then one day the car slows down and we start checking things and found this problem.will it happen again and have to switch them back? happy to have found the problem and fixed it so easy. thanks to everybody that chimed in with advice!

Replace the crank sensor, switching polarity is not normal and would think it a sign the sensor has issues. Just change it and throw the old one in the tool box as an emergency spare, just be sure to tag it as to the issue you were having.

Mike Pearson · 09-28-2015, 05:15 PM

I would also replace the sensor. My car slowed down and I thought something was wrong internally in the engine. I freshened up the engine and found nothing wrong internally. When I went to start the engine after the freshen up the engine would not start. I replaced the sensor and it started.

flash · 10-10-2015, 04:35 PM

Found the problem,crank trigger wheel was mounted backwards.that reverses polarity,which is why reversing the crank trigger wires fixed the issue. took the crank trigger wheel off and reversed it,changed wires back to correct way and it works rock solid with timing light. note- the crank trigger wheel does have a register and a small arrow pointing the direction it should rotate,but it will mount either way.I guess it was that way since we had motor out last time and just never noticed the timing moving if you brought the motor up off idle. Feel like a "dummy"

buzzinhalfdozen · 10-12-2015, 03:30 PM

Flash, I'm glad you found a problem, however I doubt that will be the long term fix as the magnets will not change polarity (ie North or South pole) due to being turned in an opposite direction. I'd still consider putting a new pick up on as it's been documented many times that they can actually change polarity. I'm not exactly sure how or why they do it but I've seen it quite a few times. Perhaps we have an electical engineer on here that may be able to shed some lite on that subject. All this of course is moot if you're not running the "flying magnet" wheel. Good luck Joe

09-25-2015, 10:54 PM	#1
flash Junior Member Join Date: Apr 2012 Posts: 89 Likes: 1 Liked 6 Times in 5 Posts	Re: msd7al-3 problem I have 0 retard chips in each retard slot.even took them out and put 4 more new ones in!

09-26-2015, 05:57 PM	#2
Tom Goldman VIP Member Join Date: Jan 2003 Location: Allentown,PA Posts: 2,473 Likes: 878 Liked 857 Times in 234 Posts	Re: msd7al-3 problem All 4 retard inputs must also be grounded besides having the zero pill in if the retard is not being used. I'd check that ground . __________________ Tom Goldman 1500 SG , 1506 STK

09-26-2015, 11:45 PM	#3
flash Junior Member Join Date: Apr 2012 Posts: 89 Likes: 1 Liked 6 Times in 5 Posts	Re: msd7al-3 problem I just checked my wiring of the car.none of the 4 retards are grounded. wired car by K & R wiring diagram and it does not show that either.easy enough to do but how does this get missed? talked to MSD twice and they never mentioned it either.will try thay tomorrow.

09-27-2015, 07:50 PM	#4
flash Junior Member Join Date: Apr 2012 Posts: 89 Likes: 1 Liked 6 Times in 5 Posts	Re: msd7al-3 problem thanks for all the advice! just thought everybody would want a followup on what was the problem and what fixed it.I tried grounding all 4 retard terminals and that did not change anything.I reversed the 2 wires from crank trigger-greem & purple wires that go to -M & +M to reverse the polarity and "that fixed it" timing is dead on 35 degrees. but the question is this-what happened or caused this to happen? wired the car 2 years ago with a K & R wiring kit.and we have checked and changed timing several times and it was always right.then one day the car slows down and we start checking things and found this problem.will it happen again and have to switch them back? happy to have found the problem and fixed it so easy. thanks to everybody that chimed in with advice!

09-28-2015, 05:15 PM	#6
Mike Pearson VIP Member Join Date: Mar 2007 Posts: 2,434 Likes: 608 Liked 1,903 Times in 571 Posts	Re: msd7al-3 problem I would also replace the sensor. My car slowed down and I thought something was wrong internally in the engine. I freshened up the engine and found nothing wrong internally. When I went to start the engine after the freshen up the engine would not start. I replaced the sensor and it started. __________________ Mike Pearson 2485 SS

10-10-2015, 04:35 PM	#7
flash Junior Member Join Date: Apr 2012 Posts: 89 Likes: 1 Liked 6 Times in 5 Posts	Re: msd7al-3 problem Found the problem,crank trigger wheel was mounted backwards.that reverses polarity,which is why reversing the crank trigger wires fixed the issue. took the crank trigger wheel off and reversed it,changed wires back to correct way and it works rock solid with timing light. note- the crank trigger wheel does have a register and a small arrow pointing the direction it should rotate,but it will mount either way.I guess it was that way since we had motor out last time and just never noticed the timing moving if you brought the motor up off idle. Feel like a "dummy"

10-12-2015, 03:30 PM	#8
buzzinhalfdozen Senior Member Join Date: Sep 2006 Location: Bellevue Ohio Posts: 984 Likes: 0 Liked 11 Times in 8 Posts	Re: msd7al-3 problem Flash, I'm glad you found a problem, however I doubt that will be the long term fix as the magnets will not change polarity (ie North or South pole) due to being turned in an opposite direction. I'd still consider putting a new pick up on as it's been documented many times that they can actually change polarity. I'm not exactly sure how or why they do it but I've seen it quite a few times. Perhaps we have an electical engineer on here that may be able to shed some lite on that subject. All this of course is moot if you're not running the "flying magnet" wheel. Good luck Joe __________________ Joe Buchanan SS/BX 3117