Originally Posted by Luna Gaudi's 72 250
Fonzi, on this video http://youtu.be/mT50BN96VmY
at the 2 minute 12 second mark, it looks to me like the dash pot is extended too far out and it is holding the idle way up. Correct me if I am wrong guys, but isn't the dash pot adjustment the last thing to adjust once the carbs are set up and running correctly? If I remember correctly I set mine to have about a 1mm gap between the adjustment screw of the dashpot and the lever on the carburetor. The adjustment screw only makes contact with the carb lever if the engine begins to die, the vacuum to the dashpot gets weaker and it extends to get the idle back up.
Also, I am wondering if you have an issue with not enough fuel getting to one of the carbs? I know you said your carbs don't have the fuel shut off solenoids, do you know if there is a small inline "metal net" fuel filter in the carb where the fuel line connects into it? My car had the same exact symptom when my front carb wasnt getting any fuel. It would run and idle, as soon as I dropped it into gear, it would just die out. If it does have that filter in the carb, maybe it is plugged up.
Your making some good progress Fonzi, don't give up.
Yes. This was part of my "screw this" mentality, and I extended that bolt. I think it need to make sure that dashpot has action in order to provide throttle in the event the engine looks like it's going to die. You are correct that it should be 1mm off, or just enough to assure that it is not always in contact with the linkage. I set it so it is just barely not in contact.
I just went out to the car to take a look at whether the bolt is pushing on the linkage. I found that it looks like it is, but in fact is not. It's just really close.
I also think I forgot to report that I left the air filter and blow by connected (forgot seal rings on the carbs before ati filter though) and started the car. It started right up, and warmed up to almost 175 in about 6 minutes or so, and I put my foot on the brake (no increase in rpm as it had before I superglued and re-taped the booster check valve) and put it in reverse. Instead of immediately stalling, it continued to run for about 5 seconds or so. Then it stalled.
During this whole test, there were no crazy-high rpms. I thought that was strange, but it ran like a regular car for the most part. Perhaps the mixture is too (?) rich? I did make one change, which was to loosen the idle mixture screws each by a half turn (to lean it out and set it closer to spec). This didn't seem to have much of an effect. I don't want to make too many changes since this is the best the car has run either since I initially got it running after cleaning the carbs, or simply ever.
It is my opinion that the dashpot is not something that will act very quickly on this car. My friend Sam described it as something that is mostly for wide open throttle sudden deceleration. I could see that working as it would be extended from an open throttle. Having the dashpot extend quickly to stop a stall when you put the car in gear seems more optimistic, but heck, what else would stop the car from stalling. Could my dashpot be bad?
As for the fuel in both carbs, my easiest measure is to test the accelerator pumps. I believe that I found the rear one was previously sucking down a lot more air before I synchronized the carbs. It seemed like that one might have also been running out of fuel. I assumed that I fixed that problem by synchronizing the carbs.
I am hoping that some minor tuning will get me to the point where the car is drivable.
I have to wonder if maybe the transmission needs some usage and if it could be normal for the transmission to transmit too much load to the engine. The car has basically been sitting for 8 years and has had the rear wheels turned this total since:
- dragged up on vehicle transport
- dragged about 2 miles on dolly
- driven in reverse out my driveway once
- driven about 1/4 mile down a hill, and up a small hill with probably no stopping at all other than switching from reverse to drive (neutral). And in both cases, downhill was the desired starting direction.
- pushed about 3/4 mile back into my driveway.
That's all the action the rear wheels have gotten in the last 8 years. Could the transmission need some fluid moving and lubrication from driving?