Does someone know what it takes to remove all emission related hardware in the engine bay? I have a '78 Mercury Colony Park with the 400ci. Goal is to clean up the engineroom. I am curious what I can remove without affecting the running engine and where to start. I know there are complete write-ups for Jeeps which describe step-by-step including pictures how to remove everything. Someone?
You're lucky its a 1978 and not a 1981 or higher. There likely isn't an on-board computer, so you can take it all off and adjust your timing. You may have to plug some vacuum lines, especially to the EGR valve. Other than that, it's no big deal. The fuel return cannister is optional, but you'd have to cut the plastic return line to the fuel tank. I left it alone, including the vacuum line from the carburetor. Take lots of pictures of the vacuum lines and use labels to identify them because it will be confusing whenever you have to rebuild the carburetor or the engine. That's why Ford make an Electrical and Vacuum Troubleshooter Manual (EVTM). Preferably 1978, or up to 1980. You can find those here. Worth every penny! http://vehicle-db.com/parts/search.pl?part=Ford+Manual A Haynes or Chilton manual will have the vacuum diagrams also. (1978 Mercury Full-Size.)
You can also study engine from earlier years (70 and newer) where the only smog related piece of equipment was the PCV valve. This should give you an idea of what was added to yours for the emission control.
I am going to have a look what can be removed. I am not used to all those vacuum-hoses and systems in this Mercury. A few years ago I had a Lincoln Continental Mark IV which drove me nuts with its vacuum controlled systems like automatic climate control. Never got it to work. The headlight-covers on my Mercury rise in about 20 minutes or so, so there must be some kind of leak. On-topic : I am going to make a lot of pictures of the engine and all the hoses/wires and try to identify the components that can be removed. That should clean her up! I have bought a Ford workshop manual on CDROM last week, but it only covers the 75 en 76 years. Bummer. I am going to look for the 78...
Install a vacuum gauge. It will tell you if you have problems with leak and engine. After it was recommended to me here on this forum, it is my most valuable gauge in the car.
Check local auto stores. Make sure you buy vacuum only gauge and not vacuum/boost gauge with light. I got mine at summitracing.com. If you have hard time finding one locally, PM me. I ship a lot of parts overseas.
It is my advice to not remove anything associated with the evaporative control systems. This is because if not done correctly the fuel tank will crush itself unless the fuel tank filler cap is replaced with a vented cap. The evaporative control system has nothing to do with performance. It only contains the fuel vapors in a canister until the engine is started and the carburator sucks the vapors in to be burned. Also the fuel bowl of the carburator is not vented and if you disconnect the hose from the charcoal cansiter to the fuel bowl on the carburator you end up with gas fumes after running the engine. I would imagine that none of this would apply if you converted the car to CNG.
Hmmm... interesting... However it's not my goal to gain performance (although the 400ci is slooooow) but to clean up the enginebay so I can finally see the engine itself But maybe you're right and I should leave everything alone. It also keeps the car more original. I am planning on converting to LPG but not in the near future. First of all I want to solve my transmission problem (another thread) and I am going to refresh all oils and filters as soon as possible. First thought was to use the Mercury during the winter, but I think I am going to store her from the rain untill I can give her a good undercoating and renew the weatherstripping.
I am not an expert on engines but you may need to swap the intake for non-EGR if you really want to clean things up. I have no idea if 78 had A.I.R. pump but you can disconnect that as well. Then there is wiring but like it was previously stated, you most likely do not have computer so it is limited. One thing that would clean the engine bay is new air cleaner. I had the snorkel type with butterfly valve. It had two or three lines connected to it plus crankcase breather line. I have replaced it with open air cleaner (360deg) which is way smaller than the original one. I have removed the butterfly valve lines, capped the vacuum line in the carb base and plugged breather in the valve. What a difference. It is like a night and day comparing to my old setup. I am running 2bbl carb so I went with 10" air cleaner. For your application you will have to go with 14" but it should still look way better. Another thing is to run spark plug wires under the valve covers. It makes things cleaner this way. You probably already have HEI but I have also replaced my points ignition with coil with HEI distributor with built-in coil. This way I was also able to remove extra brackets, coil and few wires.
The vacuum leak might be at the cannister or the vacuum manifold on the engine side of the firewall. On mine, the cannister is inside the passenger fender, mounted on the cowl A-pillar, above the wheel well cover (PVC plastic) It's just a big tomato can with hose tubes running in and out. Sometimes they rust out.
I'll second the comments on pretty much pulling things. That is what we did on my '78 Monza wagon. We really just had to watch out for a good vacuum source for the distributor, and then also make sure the various temperature activated vacuum switches were either plugged or removed & replaced with brass inserts. On that era car, an EGR can often be simply be unplugged. The usually are so far out of the air path that they will not affect anything.
