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Need Help before I lose my mind

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Now for an update on my situation. I was able to repeat the problem. Heck it happens at every light. I pulled the carb but the intake was pretty much dry. It takes so long to pull the carb that the fuel might evaporate before I got it anyway. So I got to thinking. I remembered that I bought a colortune way back when I first bought the car in an attempt to tune the ZS. Well put the colortune in #3 and watched the combustion. Strong and light blue. You can see it grow from the spark to the rest of the window. It was cool. I never got anything but sooty orange with the ZS. Anyway, even when the idle was stumbling, the colortune stayed blue. I think that indicates that it isn't loading up?

So, I reset the float height to within 1mm of the recomendation. That put the fuel height in my bowl about 1.5mm higher. Cut the timing back to 16 degrees BTC. That is closer to what Jeff told me to run. I cleaned out the small amount of debris that collected in the float bowl and pulled all the jets and tubes one at a time and made sure they were clean. I found the secondary idle jet wasn't tight but I think the oring was sealed. (At first I thought I had a eureka moment)I tuned the carb richer and lowered the idle to fall to about 900 when it stumbles. That makes it run around 1200 the rest of the time. I reset the fuel pressure to 2.0psi. I think it is an intake vacuum issue that I am having. I have no provision to measure manifold vacuum but could never get more than 14" when the ZS was installed. May still be having the same issue.
Carb spray around the throttle shafts change nothing but there is varnish on the carb and intake in the throttle shaft area. It runs really well at around 24degrees BTC but we all now that isn't safe. That is why I dialed the cam in so many times. I still think I'm just not making good vacuum at idle and I'm not sure why. Combustion numbers are good and even. Leakdown test shows minimal leakdown. Guess I'll keep pluggin away at it. I'll get it or get over it and go ahead with the body teardown. I might switch back to a stock cam when I pull the motor for paint anyway. I know I'll be drilling and tapping that intake..
JC
 
JC,

You have plugged the ported vacuum that would normally go to the vacuum advance? (Or used it as such?)

My Carter is in... have to take a photo. Nice mount, isolating rubber donuts. Still have to plumb and wire it.
 
Yes the ported vacuum connection is being utilized by the advance on the dizzy I got from Jeff.
Congratulations on the install.
JC
 
I also had same issues as you.
On my setup I went down 1 size on the primary jet and backed off on the timming 1-2 degress it amazing what a differance the smallest amout of timming that affected the idle and hot - warm starts. also got rid of 2200 rpm stumble

fuel pump on mine is a Facet this also is important as to location
keep it low and in the back these are good pumps but they cant pull worth a darn.
fuel filter can also be an issue if your using the Facet pump. due to its size and the type fuel delivery. keeping restriction thru filter to a minimum is important.I chaged it from a 1" dia. to 2' mounted fittings vert. huge differance.
 
Chris,
Which did you change the primary jet or the primary idle jet?
Thanks,
JC
 
JC,

If your colortune is light blue at idle, I would think you are too lean at idle. I am not familiar with the carb you have, but if you have an idle mixture screw, I think it would be worth enriching your idle mixture a bit (or a lot) to see if that makes the problem go away.

I have tried every which way to get my 1500 to idle smoothly at "lean" mixtures and it just flat out won't do it. It wan't lots of gas at idle.
 
Thanks Morris,
I may have to invest in a fuel/air ratio meter. It will be good to have down the road anyway. I did back off of the timing a bit further and that seemed to help some but the loading up issue is still there. No matter where the idle mixture screw seems to be. The one thing that I did notice this afternoon that I thought was interesting was that after the car has sat for about 20 minutes I found a drop of fuel on the secondary throttle shaft. It was just on the nonlinkage side and no amount of carb cleaner, wd40, starter fluid, or buetane from a portable torch would make a difference in the world. I can't help but wonder why it is leaking though. You would have to believe that gas getting out would indicate air getting in.
JC
 
In driving over the last few days, I think my issue may not be the same as JC's. I have a miss, but it's pretty constant, and not related to idle or accelleration. I'm replacing coil, cap & rotor today, and will report back. If I can find a good base line from which to start, for the DGV, maybe that'll help. (Carter 4070 in & working well.)
 
I sent an email to redline today. I left it at work though. They seemed very helpful and I think I may be able to get to the bottom of it. Today wasn't a good day for the Midget. I had to bring it back home this morning about a mile after I left for work. The last adjustment was great at idle but wouldn't run at more than 1/2 throttle. I think I blew out the powervalve letting it spit back through the carb. It was very difficult to start and just got worse from there.
JC
 
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