Guys, I don't know what else to do, but I guess I'll have to put my car in the shop....this is a last-ditch effort not to do so.

I have an 87 Bird with a 400 sbc, Carter 600 carb, headers, flowmaster, etc. The ignition is a Mallory box, MSD Blaster 2 coil, etc. A few weeks ago it started missing really badly, very randomly. Other times it would run fine (whooped an LT1 TA). Then, one day it died and wouldn't start for 4 days. Finally put new plug wires on it, because the old ones were pretty crappy. New wires, it started and ran, but runs like crap, still missing, etc. So I said screw it, changed all the plugs, have the new wires, rerouted the ignition wiring to minimalize interference, and even had the ignition module tested (passed perfectly). It still misses really badly all the time now, and I can't even get it out of the garage without it dying. I even triple-checked the firing order. Life is starting to suck. I've had thgis car for a month, paid $3k for it, and I can't drive it. Any suggestions or ideas would be GREATLY appreciated.

 

scan it for codes, make sure the tune up is good, fuel preasure and volumn are ok, do compression test ,and i'd run the valves or look at them and the push rods.

 

Hook your stock ignition back up... no MSD coil, no Mallory box, etc. See if it runs right. Go from there.

 

well, i don't have the stock ignition stuff, I bought the car set up like this. And as for scanning for codes, I don't have a computer. Any other ideas?

 

yea take off the mallory box and try jsut the coil.

 

What "box" exactly do you have? Nearly all of the amplifier boxes on the market require all of the stock ignition components to still be there: pickup coil, module, & some kind of coil. Look at what you've got, see what parts you have, and get rid of as much of the aftermarket stuff as you can. Simplify. About 95% of the time, the amplifier box is the culprit, when an ignition system fails that includes one.

If you're not able or willing to do that, then there's not much that any of us can do to help you. We don't have a magic Internet bullet we can virtually shoot your car with to make it straighten up and fly right.

Alternatively, you could just buy a complete vacuum-advance type of distributor, and get rid of all that extra stuff that (I'm guessing, with a 600 CFM carb on a 400) your motor doesn't need anyway. You could go cheap and get the Accel "blueprint" distributor which is about $125 IIRC, or get something top of the line, like a Performance Distributors DUI for more like $275. By the time a shop gets through with you, you'll have a whole lot more than $125 in it anyway, I guarantee.

 

Is the carb flooding?
Does it have a strong blue spark if you test it with a spare spark plug attached to one of the plug wires and held to ground while someone cranks the motor over?
What distributor is it? HEI ? with or without the module?

What do the plugs look like? Wet? carbon flouled?

If the spark is aratic or weak or not sparking at all you'll have to trace down the cause.
Could be the pickup coil or the little wires that lead from it.
Test it with an ohm meter.

could be the ignition module if used (HEI) the box or the cap and rotor.
One way to test the box is to trigger it by hand with the "points trigger wire". ( key on, engine off) If you can figure out which wire that is just touch it on ground with the key on should trigger the box. It will most likely be one of the trigger input wires that is not used or hooked up right now. If the box checks out, its either the
Cap/ Rotor/wires or the pickup coil.
Most ignition boxes either work or don't work at all. No in between.

 

If the distributor got lose and your timing is way off.....

It's possible. You said that it happened fairly slowly, in days not hours, the hold down clamp could be loose. Check it out, and re- check your timing.

 

You can scan for error codes with a paper clip, not a computer.

Have you tested the ignition coil? It may be breaking down internally.

 

i'm guessing he is saying his car has no computer. how could it with a carter NON CC carb?

 

I guess I should have assumed he meant he didn't have an ECM when he said "I don't have a computer". I initially understood that to mean he didn't have a computer/data logger package. DU-UH! Just slap me - I'm O.K. now...

I'd still test the coil or temporarily install a spare, even though it may not take the extra current from the Mallory box for long.

 

Yup, step one is to yank all that unnecessary aftermarket ignition stuff off of there, and put a stock one in. I'd give 8 to 1 odds that it will run right, because your problem is somewhere in one of those "enhancers".

Then if you want to make your car heavier, start adding them back one at a time, using the correct wiring adapters so that in the future when they go bad again you can easily bypass them; until you arrive at the defective component.