A GOOD ONE!!!

[motman]

OK,Where to begin, well the carb #1708 its a Buick carb. here is the question. I will preface this by saying there is a brand new MSD ready to run dist, new wires. new B+ (12V) supply to dist. the ground for dist is to the battery. ok, when it is damp (high humidity) wet. the engine will cold start and fast idle ok. but when kicked down off of high idle. the engine wants to slowly die. i can keep it running with my foot. now when its warm or cold and DRY there is no problem at all with this carb. thanks for any direction. Cliff i got the rods and jets from you so i know they are right. this all sets ontop of a 400 pontiac with 408-408 lift. nothing crazy good vacume 17+ at idle. any direction would be great thanks.....

[motman]

OK,Where to begin, well the carb #1708 its a Buick carb. here is the question. I will preface this by saying there is a brand new MSD ready to run dist, new wires. new B+ (12V) supply to dist. the ground for dist is to the battery. ok, when it is damp (high humidity) wet. the engine will cold start and fast idle ok. but when kicked down off of high idle. the engine wants to slowly die. i can keep it running with my foot. now when its warm or cold and DRY there is no problem at all with this carb. thanks for any direction. Cliff i got the rods and jets from you so i know they are right. this all sets ontop of a 400 pontiac with 408-408 lift. nothing crazy good vacume 17+ at idle. any direction would be great thanks.....

10 deg of base time total 36
               14 inch 4 open breather
               1 inch spacer (for heat)
               baseplate bushings
               stock carb other than jets and rods

[Cliff Ruggles]

I wouldn't think that humidity would have anything to do with carburetor operation, but temperature would.

Are you using the vacuum advance, and is it hooked up to ported or manifold vacuum?......Cliff

[motman]

Cliff, its ported middle right side of carb. also what float level do you use on this carb.

[motman]

Cliff, also here is a strange thing that happen when it does this. to me it sounds like the engine is sucking to much air. no vac leakes, like i said runs great in all weather except rain and snow (damp). have checked pulloff works,have checked choke function ok. man im going to pull out my last good hair LOL thanks man for your help.....

[makomark]

motman - did you put the high voltage side together with a good silicone dielectric grease? I've seen those MSD systems find some 'tiny' electrical leaks, especially on tunnel boats. The spark energy will take the path of least resistance and those paths seem to multiply when damp. Make sure the boots on either end of the wires are clean, grease them up, and give it a whirl.

[Cliff Ruggles]

Set the float at 1/4".

Have you checked the timing with a timing light to see if some of the timing is in at low rpm's, then falling out as the engine speed decreases?......Cliff

[motman]

To all of the above yes, greased all fittings. Cliff just installed your bushing kit, boy that was sweet. nice drill bit..So here is what is going on. after total rebuild. I use a 1 inch plastic spacer and a flat gasket from spacer to manifold and the stock gasket on carb mating surface. on first startup choke in started fine let run until engine was at temp.checked to see if any timing was being pulled in at temp there was none. pulled down into gear and let it stand there and sure enough she started to cough, put back in park, slower than normal ilde but smooth, reved motor idle back up then back down. i even was watching the voltage on my dmm as this was happening there was a solid 14 volts on coil + and 13.38 on the - side. all is well on supply voltage. So at this point i am so pissed off that i shut her down and walked to the tool box and grabbed my adjustment tool for the mix screws. reached in to the window and fired it up. there was no problem after that i didnt adjust a thing even pulled her into drive no coughing no su ???rging nothing. smooth as a babys butt. got any ideas.. thanks chris