Is it possible Im blowing the spark out?
Thread Starter
Registered User
Joined: Jul 2000
Posts: 2,735
From: Buffalo, NY
Is it possible Im blowing the spark out?
My car is still missing from time to time predictably around 5200 rpms or so. I have replaced everything and Im mean everything that could possibly cause an upper RPM miss. My last resort will now be an MSD 6a or 6al going on the thought that the spark maybe getting blown out. Is this at all possible on an NA car? I know its heard of on blower cars...
Registered User
Joined: Oct 2002
Posts: 998
From: abington MA
yes its possible
i had a 4cyl truck that blew out 7 spark plugs. cannot figure that out for the life of me. i mean at the same time all 7 of them just exploded. i replaced all 8 and never had a problem again. i still have 2 of them to show people because they are that strange looking
i had a 4cyl truck that blew out 7 spark plugs. cannot figure that out for the life of me. i mean at the same time all 7 of them just exploded. i replaced all 8 and never had a problem again. i still have 2 of them to show people because they are that strange looking
Registered User
Joined: Feb 2003
Posts: 641
From: St. Charles, Il
What wires are you running? coil? The Multiple Spark Discharge stops at 3000RPMs I think, mabye 3500 with any MSD system, but the system changes a few other things that might help if that is actually your problem. if nothing else it'll save ya some gas money. and we all know how much that would help with todays gas prices...
Registered User
Joined: Feb 2003
Posts: 641
From: St. Charles, Il
I read a 4 page article once compareing the different MSD systems, MSD, jacobs, accel ect.... and basicly all of them have 3 sparks at low RPMs which helps with emission and fuel economy ect and 2 sparks at like 2000-3000 rpms which helps with emissions fuel economy and power a bit but after that there is no multible spark. It also supposedly makes the spark hotter so I suppose if it was going to help you that is the only reason why it would...
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Joined: May 2002
Posts: 4,579
From: Cincinnati, OH
Originally posted by 96z
Dave Feerst, the MSD 6a or 6al wouldnt help in the upper RPMs at all?
Dave Feerst, the MSD 6a or 6al wouldnt help in the upper RPMs at all?
Registered User
Joined: May 2002
Posts: 4,579
From: Cincinnati, OH
Originally posted by madwolf
Don't forget than MSD ignitions have been suspected to ruin optisparks by putting a higher voltage through them. FWIW, I used to have a 6AL and it did nothing for me....
Don't forget than MSD ignitions have been suspected to ruin optisparks by putting a higher voltage through them. FWIW, I used to have a 6AL and it did nothing for me....
Thread Starter
Registered User
Joined: Jul 2000
Posts: 2,735
From: Buffalo, NY
Originally posted by madwolf
Don't forget than MSD ignitions have been suspected to ruin optisparks by putting a higher voltage through them. FWIW, I used to have a 6AL and it did nothing for me....
Don't forget than MSD ignitions have been suspected to ruin optisparks by putting a higher voltage through them. FWIW, I used to have a 6AL and it did nothing for me....
Registered User
Joined: Nov 2002
Posts: 4,784
From: Jacksonville
An MSD box produces multiple sparks till about 3000 RPM, then it concentrates all the power into a single, powerful spark. 
I've heard the rumors that ignition boxes can lead to opti failure, but I've never actually seen any evidence to prove or disprove it. Oh well, LTCC here I come.
I've heard the rumors that ignition boxes can lead to opti failure, but I've never actually seen any evidence to prove or disprove it. Oh well, LTCC here I come.
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Joined: Nov 2003
Posts: 1,770
From: Mishawaka, IN
More power through the opti means more stress on the opti. As to how much it will take off the life of one, who knows, since opti problems don't show up at the same time in all cars. I think that it reduces the life of the cap to a certain extent, at least. I've looked at the msd boxes before but I don't think I'll be getting one, I've got a new cap & rotor right now, don't want to mess it up. If I'm going to try to get more energy to my plugs it will be delteq or ltcc. Those systems make more sense to me anyway, since you don't have to worry about a rotor falling apart if you're running in the 6-7k rpms area.
I think if you modified the opti as a straight-thru design (the terminals on the opti go straight to the wires instead of snaking their way through to make the wires look pretty) it would probably last a lot longer, a lot less prone to arcing. The wires would be harder to work with, but the cap would probably cost less to replace that way too.
And why did GM use the opti anyway. The pcm already controls the timing anyway, it seems like it would have been a fairly simple step to mount some coil packs up somewhere and be done with it. Were they just trying to bring in more money for repairs???
Anyway, my favorite thing about the opti has got to be the extremely accurate timing. Least favorites would have to be the inconvenient location and the low amount of energy that actually makes it's way to the plug.
I think if you modified the opti as a straight-thru design (the terminals on the opti go straight to the wires instead of snaking their way through to make the wires look pretty) it would probably last a lot longer, a lot less prone to arcing. The wires would be harder to work with, but the cap would probably cost less to replace that way too.
And why did GM use the opti anyway. The pcm already controls the timing anyway, it seems like it would have been a fairly simple step to mount some coil packs up somewhere and be done with it. Were they just trying to bring in more money for repairs???
Anyway, my favorite thing about the opti has got to be the extremely accurate timing. Least favorites would have to be the inconvenient location and the low amount of energy that actually makes it's way to the plug.