ok, i changed the coil and the ignition module....now the engine feels like it's misfiring.....all plug wires are hooked up......rotor looked slightly worn, but not too bad......any ideas? it wasn't doing this before i changed the parts.....actually...wasn't doing this after the coil..but is doing it after i changed the module......please help!!

 

Are you sure you put the plugs in the right position on the cap? I know I changed 2 the other day and mixed them up.

 

which is a good time to point out that you should replace plug wires ONE at a time. take one off, then put the new one on. do NOT take them all off then put all the new ones on.

 

Also, if you went through all the reouble to remove the cap for the module change, you should replace the cap and rotor then. I have found in the past that the engine may have been running fine when you took off the cap, etc for maintenance, but when you put it back on the car will run like crap. Just disturbing a worn cap/rotor and putting them back on can be enough to cause problems.

~M~

 

Yep, that's what I normally do. But this time I took both off not thinking, and soon as I did, I was like oh crap.

 

Did you use the white grease on the module????

 

used white grease.....checked and re-checked the plug wires...all are where they should be......the cap was almost brand new....and the rotor is new....it looks slightly worn, but not really bad........i can't figure out what went wrong on this thing.....i even put the old module back in and it's still doing it......i am stumped......it's misfiring bad enough to make a slight backfire every now and then......someone please help...this car is driving me nuts

 

where is the timing...what are the plugs gapped at?

 

plugs are gapped however they were when i bought them......timing hasnt' changed......the car wasn't doing this before i replaced the ignition module and took of the dist. cap.....it had to have been something i knocked off while replacing the module

 

in that case I would gap the plugs around .45..then I would make sure the wires that plug into the modual are not crisp or cracked or both, after that I would look at the Pick up coil...thats gotta be it...maybe

 

Did you take the coil out of the cap? If you did, did you put the wires back in the proper place (coil wires that is)?

~M~

 

my coil's not in the cap....also, my pickup coil is new, replaced about a month ago......this is driving me insane

 

If its backfiring, then you definatley crossed a plug wire, no doubt about it. I did the same thing a long time ago when I installed my headders. Recheck them, Im positive thats your prob.

 

New: P/U coil, Newplugs,new coil,new ignition modual, wires in proper order......Hey, Change the cap and rotor......it may have a hairline crack you cant see. While your at it change the rotor, May as well eliminate All the ignition parts. (As Morley Said)

I think I would be a little more thorough,about specs...gap the plugs, factory settings are not accurate...check the the timing with a light all this messing around the dist. may have moved something. Make sure the clamp is tight. Check for any freyed or bare wires leading to the dist..
If none of this helps, I too am stumped. I bet it is something really simple, usually is...just to be sure

 

Check wires 5 and 7 very closely. Since they are adjacent to each other both physically and in the firing order, it's an easy mistake to make. I've done it myself more times than I'd care to admit.

What kind of coil did you use? Some coils don't match the OEM HEI module correctly.

 

definately no crossed wires...i check them all twice, my friend checked them twice......everything is where it should be......there has to be something else that could have caused this.....is it possible the computer got messed up when i changed the module.......i'm kinda grasping at straws here......i don't get it

 

There are a couple different varieties of HEI modules, too.

Another thing to be mindful of is that if you connect the pickup coil leads to the HEI module backward (the connector WILL flip) the timing will be off since the trailing edge of the trigger pulse will be way off, and introduced on the wrong lead. It will still run, but very poorly. Don't ask how I know this....

 

nah, it's not an HEI......i think i'm gonna surrender and take the thing in......i think it's time to take the ol' TPI off and go w/ the 4 bbl.

 

I give up.....(No BS just white flag)
good luck

 

I was under the impression all SBC & BBC HEI Dist. were all the same and interchangable....is this not fact?


Dont know how you guys got HEI out of his set-up...