MSD ignition

Mopar 340 · 03-26-2018, 09:10 PM

Just put new msd ignition and msd distributor on my car, and at idle the rpm jumps around about 300 rpm. Timing is set at 36 degrees and I have 1 blue spring and 1 light silver spring in distributor with a blue bushing. Any suggestions on getting it to idle without jumping up and down?

GTX JOHN · 03-27-2018, 04:46 AM

We run both light silver springs if we do not lock out the distributor.
Simple job to rotate distributor on shaft to lock it. If that fixes it it
is probably advance springs......Drag cars often work fine with it locked
even without starting retard.

pmrphil · 03-27-2018, 08:17 AM

I'd suggest that you verify with a timing light that a timing variation is the cause of your idle changing - if it is, just change to a bit stiffer spring.

Rod Greene · 03-31-2018, 08:35 PM

Like John said lock it out and forget about it.

Kenny Bomar · 03-31-2018, 10:21 PM

I've seen a bad plug wire make the timing jump around on a locked out distributor u mite check them

03-26-2018, 09:10 PM	#1
Mopar 340 Junior Member Join Date: Dec 2017 Posts: 25 Likes: 0 Liked 6 Times in 4 Posts	MSD ignition Just put new msd ignition and msd distributor on my car, and at idle the rpm jumps around about 300 rpm. Timing is set at 36 degrees and I have 1 blue spring and 1 light silver spring in distributor with a blue bushing. Any suggestions on getting it to idle without jumping up and down?

03-27-2018, 04:46 AM	#2
GTX JOHN VIP Member Join Date: Jun 2009 Location: Boulder City, Nevada 89005 Posts: 2,736 Likes: 2,808 Liked 2,487 Times in 698 Posts	Re: MSD ignition We run both light silver springs if we do not lock out the distributor. Simple job to rotate distributor on shaft to lock it. If that fixes it it is probably advance springs......Drag cars often work fine with it locked even without starting retard. __________________ John Irving 741 Stock 741 Super Stock

03-27-2018, 08:17 AM	#3
pmrphil Member Join Date: Aug 2010 Location: CT Posts: 460 Likes: 1,815 Liked 348 Times in 152 Posts	Re: MSD ignition I'd suggest that you verify with a timing light that a timing variation is the cause of your idle changing - if it is, just change to a bit stiffer spring. __________________ Phil Molski PMR Performance S/C 1623

03-31-2018, 08:35 PM	#4
Rod Greene Senior Member Join Date: Mar 2002 Location: TN Posts: 530 Likes: 425 Liked 242 Times in 81 Posts	Re: MSD ignition Like John said lock it out and forget about it. __________________ Rod Greene Real men shift for them selves. Slowly working on TA Challenger for D,E/S and a 72 Challenger for SS/K, L as if I don't have enough other projects.

03-31-2018, 10:21 PM	#5
Kenny Bomar Member Join Date: Nov 2002 Location: mphs tn Posts: 224 Likes: 3 Liked 425 Times in 51 Posts	Re: MSD ignition I've seen a bad plug wire make the timing jump around on a locked out distributor u mite check them