hey guys i have done a search on this and did not get the result i wanted i installed a msd blaster coil after that the engine started miss firing so i installed accel 8mm spiral coiled wires and new r45ts plugs it has stock points and stock rotor and stock cap all the wires are separated well could fire be jumping around in the cap.the car idles find but when put under a load it starts miss firing.this started right after i installed the coil.thanks jeff

Sounds like maybe a wire isn't performing that good leaving the unburned cylinders fuel to burn after exhausted. Or if you are running a distributor with a condensor in it maybe the condensor is freaking with the extra juice and shorting power out once in a while. The old condensors flake out. Small trace dust or even unseen coating will give high voltages easy paths. Turn the mixture up and you'll have a rocket. Uh that's not right. Posibly the spark plug gap needs to be changed for the coil added. I have heard of times where the firing order gets mixed up but the motor seems to run smooth till power is needed. Maybe try watching the engine compartment when it's all dark watching for flash overs of the HV. Maybe wipe out the cap real good to eliminate possible voltage losses there that would leave fuel not being burned. You didn't change the timing or distributor right? Good luck.

i did crank the engine last night it was very dark and no signs of arcing anywere.same distributor same points and condenser .it has stock points set cap and rotor that was recently replaced.thanks jeff

Misfiring under load sounds like a really bad exhaust leak close to the manifold or possibly an exhaust lobe on the cam starting to go flat.

Are the coil wires connected backwards? That's exactly what happens when the power feed is connected to the (-) terminal and the distributor wire is connected to the (+) terminal.

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JohnZ
CRG
'69 Z28 Fathom Green

hey guys i installed new blue streak cap rotor and point set and the engine would run good for a few minutes and the it got were it would not even idle after i set points at 30 and timing at 12 btdc .the coil zapped the condenser i believe .installed another point set and reinstalled my old coil and it is running great now .could this coil be bad.i did have the coil installed properly primary to + secondary to -.thanks jeff

Some of these aftermarket coils require a resistor in addition to the factory resistor wire. My Accel super coil had specific voltage requirements listed in the instructions. This voltage at the coil must be measured at charged battery voltage as if the engine was running (13.5-14 volts). I think my super coil needed something like 7-9 volts. I needed a ballast resistor in addition to the resistor wire to come up with that. I'm using an infra-red trigger conversion in a points distributor. The trigger was designed to work with the resistor wire so it's wired to the feed side of the ballast resistor and the coil is wired to the load side. I check the timing every spring and haven't had to adjust anything in eight years. Something to think about.

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'69 RS Camaro
355 5-speed 4.11

ok, are you sure your not overlooking the obvious? are the plugs gapped correctly? does the rotor in the distributor have alot of gunk and corrosion on it? i am not disagreeing with any of these other posts, all i am saying is to check the obvious before you go out and spend more money on a ballast resistor, or another points kit.

At the bottom is what www.msdignition.com (http://www.msdignition.com) has to say about probably their whole ignition system trouble shooting. I'd say if those wires are solid wires not carbon or whatever is required for the hot spark... one oops. I'd call their hot line. (915) 855-7123
MSD TECH LINES are open Monday thru Friday from 8am to 5pm Mountain Standard Time. The last issue I was posting as a possible solution to a guy a little while ago. I think it's ford who has a spacer if left out you get the cam walk. Never thought of it as being tell tale by a bowed out timing chain cover. BFH right hehehe. Anyway I read some place about a guy having a problem with some spark plugs not performing till up to temp. I'm not sure but it appears the manufacturers idea is multiple pulse sparks for fuel ignition so maybe the speed the coil drumps it's voltage isn't fast enough with other stock parts. I'd be more prone to think the high voltage is swamping the rest of the system out like a tesla coil. One of my worst experiances is to not check the ground quality. You can have a ton of voltage but if the ground aint in there good the flow sucks. Namely one set of points and condenser forgotten to be screwed down tight while and after adjusting. I had to finally stand there thinking and figured it out. Good luck.
Here's the manufaturers comments.

What kind of timing light are you using? Many lights have trouble reading the MSD's capacitive discharge multiple sparks. Dial back timing lights are not recommended. Try another non-adjustable light and check the timing again. MSD offers a Timing Light, PN 8990.
Make sure you are not using Solid Core wires.
Inspect the routing of the Magnetic Pickup Harness. It should be routed clear of the coil primary wires and plug wires. It is best to route it along a ground plain such as the firewall, frame or engine block to form a shield around it.
Check the polarity of the magnetic pickup wires of the distributor. Reverse the connectors and check the timing again. The correct polarity is whichever connection gives the most retarded timing.
On Chevrolet engines, if the timing is retarding 10 - 20 degrees inspect for cam-walk. This is especially prevalent on engines with a chrome or stock timing chain cover that is actually bowing forward allowing the cam to "walk".