so i have a new fully built motor with vortecs cam ect. i have put a few hundred miles on it at 20 psi or so no issues no knock. i swapped out my msd box for a new 6al2. i drove it to work this am and pulled mint. all of a sudden the next time i got into it, it started breaking up bad. so i turned the boost down and same issue. i took the msd box off and ran the coil off the factory wires and it seemed to run ok. but when i turned to boost back up to 20 or so psi it breaks up again.....not as bad but still is. are the factory ignition systems with more power and methanol good enough without an ignition amplifier of some sort? its a brand new delco coil as well. thanks
new build,weird problem
- Thread starter Ls10
- Start date
randy merritt
Donating Member
Re: new build,weird problem
what plugs? I had a similar problem running 7 heat range plugs. I switched to 6 heat range, then no issues. I had the same 6al2 box, then went back to stock ing.
what plugs? I had a similar problem running 7 heat range plugs. I switched to 6 heat range, then no issues. I had the same 6al2 box, then went back to stock ing.
autoaddictions
Active member
Re: new build,weird problem
Did you hook up the 2 step feature? If you did and you used the brake switch wire it will bleed 2 volts or so and intermittently cause the 2 step to activate while driving. You are far better off with a 2 step button not the brake switch by the pedal. Hope this helps! if not this i suspect bad cap, rotor, ignition module, wires are rotten and fraying that connect to the ign module under cap. Spark gap to wide tighten up a bunch and see what happens.
Did you hook up the 2 step feature? If you did and you used the brake switch wire it will bleed 2 volts or so and intermittently cause the 2 step to activate while driving. You are far better off with a 2 step button not the brake switch by the pedal. Hope this helps! if not this i suspect bad cap, rotor, ignition module, wires are rotten and fraying that connect to the ign module under cap. Spark gap to wide tighten up a bunch and see what happens.
Re: new build,weird problem
2 step is on a separate button, new brass cap and rotor,new GM ignition module. I'll try to tighten the gap up and check the wires. Just weird how one pull was fine and one pull wasn't. I still think the msd box is bad because it breaks up under low boost with it on but doesn't break up in stock form under low boost
Don W.
Stab it and steer it
Re: new build,weird problem
IMHO .028 is fine. That's what I run with no issues. Unless you're using the 2-step leave the MSD disconnected. You answered your own question above by saying it doesn't breakup with the MSD disconnected. With GOOD WIRES the stock ign system is pretty stout. I run stock everything except Magnacor wires which made a noticeable difference even at idle.
It's difficult to properly check the wires. What happens is they check fine but "under load" IE boost, the insulation beaks down and they short to ground causing a miss-fire. This is what mine was doing until I switched to the Magnacor's. I went through 3 different wire sets before the Magnacor. No I don't work for them but the darn things just worked. :lol: Others have had good luck with all kinds of wires. To each his own I guess.
Cyls 2 & 4 need special attention due to the heat from the turbo. I could easily be one or both of those. Check those 2 first.
If you need the 2-step (I assume you do since you have it connected) you could just disconnect the signal wire for the 2-step and see what happens.
Side question. How steady is the tach needle at idle?
HTH
IMHO .028 is fine. That's what I run with no issues. Unless you're using the 2-step leave the MSD disconnected. You answered your own question above by saying it doesn't breakup with the MSD disconnected. With GOOD WIRES the stock ign system is pretty stout. I run stock everything except Magnacor wires which made a noticeable difference even at idle.
It's difficult to properly check the wires. What happens is they check fine but "under load" IE boost, the insulation beaks down and they short to ground causing a miss-fire. This is what mine was doing until I switched to the Magnacor's. I went through 3 different wire sets before the Magnacor. No I don't work for them but the darn things just worked. :lol: Others have had good luck with all kinds of wires. To each his own I guess.
Cyls 2 & 4 need special attention due to the heat from the turbo. I could easily be one or both of those. Check those 2 first.
If you need the 2-step (I assume you do since you have it connected) you could just disconnect the signal wire for the 2-step and see what happens.
Side question. How steady is the tach needle at idle?
HTH
Re: new build,weird problem
I'm going to try new wires. Old ones are some Accel wires that were "new " when I got the truck. I'm going to pull the plugs as well. Maybe they are just weak and the msd was just helping an underlying problem. I noticed even stock motor it would break up a bit in more boost without an msd box. That's why it's all new GM parts. I just thought the stock ignition system wasn't strong enough
I'm going to try new wires. Old ones are some Accel wires that were "new " when I got the truck. I'm going to pull the plugs as well. Maybe they are just weak and the msd was just helping an underlying problem. I noticed even stock motor it would break up a bit in more boost without an msd box. That's why it's all new GM parts. I just thought the stock ignition system wasn't strong enough
