scratching my head ? engine stumbling
 

my engine acts like its almost running on 7 cylinders kinda out of the blue, 2000 miles on a gm crate with new everything. eldeblock 600 carb., edel fuel pump and intake, summit hei. engine was running fine, last thing i did to the engine was adjust the idle mixture srews, ran fine after that until i started one morning about a week later then it had the miss. heres what i"ve done since then. had ignition module checked, changed plugs. wire , cap, rotor, checked voltage to the hei, fuel filter clean, adjusted ims about 3 turns out, choke opens up properly, timing has not changed (10degree) seems to be getting plenty of fuel, engine is not smoking. i have not done a compession check but doesn't seem cylinder related. so im kinda scratching my head now, is there anything else i've i need to check? thanks

Sounds like you have eliminated the ignition system, better do the compression test. Is this a steady skip or a random misfire?

If it's random, check your ground and the wire to the distributor, before you do a compression test...mine was the ground and the power wire. It was dropping 500 rpm at will. Found the dissy wire almost apart (inside the harness no less) and wired to the alternator.

only thing i've noticed different is when i adjust my right side idle mix. screw in all the way it does not want to die out like before, the left side will die out if i adjust it in. what would be the procedure for checking and cleaning the IMS ?

Take mixture screw all the way out and and use air hose to blow out the passage. This wiil probably cure your problem as the idle passage is stopped up if it will not affect the idle speed.

:agree:

i got a chance to blow out the ims, no more stumble ran great. reset ims to edelbrock recommendation ran fine for awhile then started to stumble again on road test. i'll blow out again tommarow and see what happens.

Have you checked your fuel filters? Sounds like trash is getting in.