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MSD problem

Posted: Thu Jun 14, 2007 7:59 am
by julven
I need to know if I have been feed a line of bull or if I have a problem. I have a sbc with a 6AL and 8982 retard with a MSD dist locked. With the car idling at about a 1000 rpm it has 35 degrees rock steady then as I rev the engine it start to slowly retard the timing about 4-6 degrees with out the retard engaged then you can engage the retard and drop another 4 or what ever the retard is set at out. My concern is the slow retard that this dist and 6Al has never had before. I did add the 8982 but it seems to do its job so I have a hard time condemning it and the way it is wired I haven’t removed the 8982 but I will tonight. I called the MSD tech line and talked to two different guys and got two different answers and don’t like either one of them. First I was told I had a junk timing light well that could be as it is older than I am and I use to play Star Wars with it as a kid so I got another one and it still does it. I called again and now I am told it is normal add what ever it retards at the crank and it will be okay. So If I want 35 make it 39. I don’t feel good with that answer either because it never did this before. They said it is to do with the windings in the pickup coil. Well it is the same dist as last year and it didn’t do it then. I know all this keeps pointing to the 8982 as I added it but it will do its job. Has anyone run in to this or seen it before. Thanks. Jason

Posted: Thu Jun 14, 2007 9:08 am
by John_Heard
Lemme guess, you don't have a crank trigger do you?

Posted: Thu Jun 14, 2007 9:29 am
by julven
No I don't.

Posted: Thu Jun 14, 2007 9:40 am
by John_Heard
The slow timing retard is your cam moving. Even with a button things deflect and move around. Anyway, if you want to get rid of it put a crank trigger on it, then it'll be rock solid.

When you order make absolutely certain to get the MSD pickup cable with the shielded ground wire.

Posted: Thu Jun 14, 2007 9:49 am
by julven
This is a new solid roller cam that we have never run so this would be new to us(cam walk). Would you add the retarded amount to the idle value?
Does this show that I have to much movement?

Posted: Thu Jun 14, 2007 10:30 am
by John_Heard
Well you want to figure the amount of retard that it has at the RPM you're going to be running it at into your calculations for how much to pull out when on the spray.

You're getting movement somewhere, could be too much gap in the cam button, or deflection of the timing cover, or maybe something to do with the timing chain.

You might see if you can stick a big screw driver/pry bar between the back of the water pump and timing chain cover to brace it more and see if that alters the timing retard when you rev it up. Many people would be surprised to see how hard a cam will push on the the timing cover.

Posted: Thu Jun 14, 2007 12:19 pm
by julven
I don't even need my retard with how much this thing backs off.LOL!
I bought this cover and was told by Comp that it would be the proper height and wouldn't need adjustment and wouldn't need to worry about this.Somethings are to good to be true.
http://www.compperformancegroupstores.c ... gory_Code=
And this is my chain
http://www.compperformancegroupstores.c ... gory_Code=
I will try a screw driver tonight and see. I have seen guys put a theared tube with bolts behind the pump to push back. Is that a good option until I can get a crank trigger?

Posted: Thu Jun 14, 2007 12:31 pm
by John_Heard
The brace behind the pump will help I'd bet.

For you other guys that are reading this, if you know why some motors are a LOT worse about this than others it would sure be nice to know why...

Posted: Thu Jun 14, 2007 12:32 pm
by julven
Thanks John.

Posted: Thu Jun 14, 2007 4:57 pm
by krazyhorse
i had that same problem and I added some more valve spring pressure and it did work i didn't have a timing change any more. the extra spring pressure helps hold it in even though it is not ground that way.also when you launch the cam goes back just like the crank.

Posted: Fri Jun 15, 2007 7:49 am
by julven
I found where the problem is last night we feel. We had some other Msd dists and boxes to try and took one out of another motor and the retard was gone. Timing was steady from idle to above 5000 rpm. So we took the pickup out of the dist that didn't move and put it in the dist that had the problem and it is still there (the retard)so I feel it has to be in the shaft,housing or rotor. Jason

Posted: Fri Jun 15, 2007 7:57 am
by John_Heard
Good deal sounds like you've found it. So there was too much slop in the shaft on that distributor?

Posted: Fri Jun 15, 2007 8:28 am
by julven
Well that is the thing kind of lost now this dist that is retarding only has 30 or so passes and feels tight compared to the others so shaft twist or rotor phasing or ???. What do you think. I am going to try MSD for fun later.

Posted: Fri Jun 15, 2007 8:44 am
by John_Heard
Does the one that was retarding have play up and down?

Posted: Fri Jun 15, 2007 8:55 am
by julven
Yes it has some.