Gents; 78 carbed 308. Can someone help me with where the hose from the air intake cleaner closing valves goes to. I just pulled the air intake housing off for the first time and didnt see that it was connected anywhere. Any problems with the valve being open all the time? Thanks in advance. Image Unavailable, Please Login
There's no operational problem if that actuator nipple is left open to atmosphere because the logic is: no vacuum on actuator = end flap inside air cleaner open (which is how it should be when the engine is running) vacuum applied to actuator = end flap inside air cleaner closed but you will let gas fumes out to atmosphere from the air cleaner after shutoff (just like the '73-'77 US 308). However, if you don't have this "air cleaner end flap closes at shutoff" system installed and working, you should also confirm that the fitting on the intake manifold of cyl #8 is blocked off/plugged -- see jpeg. Image Unavailable, Please Login
i took it back apart, see pic below, it looks like the system is closed (ie, no open ends) but its not plugged, and its not connected to the flap closer.....any thoughts? Image Unavailable, Please Login
Your system looks rather "modified" (that hose connecting two of the ports together on the electrovalve above the water pump is definitely strange). There should be no continuous airflow into that fitting on cyl #8 (i.e., it should be pulling a vacuum on a completely closed system). This jpeg shows how I'd recommend that you hook things up (if you've still got all the bits) -- it doesn't show the small fan motor associated with the middle fitting on the charcoal canister. The end flap actuator line should go to the fitting on the top of the electrovalve. Send me a PM with your email address, and I'll send you the diagram of the "stock" arrangement that FNA provided to me when I made an inquiry about the same issue. In the stock arrangement the small metal tubes on 1-2 and 5-6-7-8 are connected to the top of the charcoal canister (and "open" system) and the small tubes on 3-4 are connected to the front of the other electrovalve controlling the diverter valve (a "closed" system) . What I didn't like about this is that (at idle) about 0.5 kg/hr of air flows into each cylinder of 1-2 and 5-6-7-8 while no air flows into 3-4 -- and this airflow difference won't be detected by the Syncrometer. By hooking all eight of the small metal tubes to the top of the charcoal canister each cylinder ingests the same amount of air. The other slight difference is that in the stock arrangement the diverter valve will only actuate at high RPM and closed throttle conditions (i.e., high vacuum). By connecting the electrovalve controlling the diverter valve to the vacuum sphere (where high vacuum is always present due to the check valve), the diverter valve will always actuate at high RPM regardless of the throttle condition. Image Unavailable, Please Login
Steve, just resurrecting this thread to make sure I understand exactly what is going on (given my DV problems). Does the above statement mean that at low RPM, air is getting pumped into the injectors? I need to pass emissions, and as I understand it, your revised routing will not affect the normal operation of the system at low RPM. Is that correct?
Are all the vacuum connections the same? I've removed the all of the evaporative emissions system off my '78 and plugged the lines. But, I did the connect the "joined" vacuum lines off of cylinders 3&4 to the diverter valve (see the above diagram). The vacuum line off of the end of this same carb still goes to the brake booster. Is there any problem in that?
I'm hoping that you said this a little wrongly. If you hooked the small vacuum tube from the 3&4 intake manifold directly to the diverter valve, this wouldn't be so great as the diverter valve would just almost always be held open. If you mean that you hooked the small vacuum tube from the 3&4 intake manifold to the electrovalve controlling the diverter valve, this would be fine (if you have the small vacuum tubes from the 1&2 and the 5&6&7&8 intake mainfolds blocked -- i.e., in your configuration, all of the small metal vacuum tubes on the intake manifolds are either connected to a closed system or blocked).
Thanks Steve...yes I meant that I hooked the small vacuum tube from the 3&4 intake manifold to the electrovalve controlling the diverter valve. So, there's no difference in the vacuum from the small tubes as opposed to the larger ports coming off the end of the 3/4 or 7/8 carbs?
Yes, don't see why they would be much different as all are connected to essentially the same source area between the carb throttle plate and the intake valve.
I dont have a flapper and still cant figure out what they do? Draw fumes from the gas tank through the canister into the engine??????
The airbox flap was added in 1978 to the '78-'79 US/NA versions. It prevents the gas fumes that waft up out of the carbs after shutoff (and the oil fumes from the crankcase) from drifting out the air intake in the side of the bodywork. The small electric air pump runs for ~3 minutes after engine shutoff and evacuates these gas fumes out of the airbox thru the charcoal canister (which dumps the "cleaned" air out to the atmosphere). Stick your nose in your '75's bodywork air intake a couple of minutes after engine shutoff and take a deep breath -- you'll get the picture
Does anyone know where I can get some "T"'s to do this I need 1 "T" with two 6mm ends and one with 3 8MM ends? To do the setup in Steve's drawing?? Rob
