New Thing owner with an egr filter question

[rhubarbray]

First of all, hi! My wife has just acquired a '74 Thing and she loves it. It's in fairly good shape cosmetically but needs a little help. My brother had it for a few years and didn't do too much to it but also didn't put many miles on it. When we got the car many tune-up things were off. Valve clearances, seized choke, just to start. But I'm getting there. Now, when I was working on the carb I noticed when I pulled the egr connection with the line on it going to the air filter off I noticed the union going through the lower sheet metal was loose. I looked underneath and there was just an open rusty hole! So I dug through the parts manual that came with the car only to find out we seem to be missing the egr filter. Looking that up I can see how the one connection to the union works but the other end goes where? I don't see any open connections or threads in that vicinity.
I'm also guessing this may be why the car doesn't run that well at idle. I just reset the air bypass and mixture setting to stock in order to make some adjustments and it pops quite a bit on decel and stalls when I come up to a stop and does NOT want to restart. I'm guessing quite lean.

Ray from Ottawa, Ontario

[SilverThing]

Hi Ray, Congratulations on the new Thing and welcome to the forums!

The EGR filter does indeed go underneath that sheet metal union. The other end of the filter connects to the muffler right at the flange that bolts to the exhaust port on the heads. Most mufflers out there, even the stock replacements, don't actually have the proper connection for EGR. Someone who is adept at welding could probably work out a way to adapt a connection, if you want it. EGR isn't the horsepower robbing evil that people make it out to be. It only operates at partial throttle.

Without the filter present, the easiest way to disable the system (temporarily or permanently) is to disconnect the vacuum connection from the carburetor to the valve. Be sure to cap the port on the carburetor or you will be dealing with an air leak.

Before messing with the carburetor, make sure your valves are adjusted properly on a cold engine. Next make sure your ignition is in good order and set properly. Many people (myself included) will misdiagnose an ignition problem as being a carburetor problem. Which distributor are you running on the engine?

The bypass and mixture screw positions are general starting positions to get it running enough to adjust. I normally adjust in quarter turns at a time with a pause to give the engine some time to react. Most engines it isn't terribly difficult to get a good idle that doesn't pop on decel. I find when I get it right, it will start and idle well even when cold. My engine is particularly sensitive to both the mixture and bypass adjustments (probably because of the camshaft not generating much idle vacuum). There is a sweet spot with both screws where it comes together and idles well.

One of the common issues folks have with the stock carburetor is air leaks around the throttle shaft. See if you can wiggle the shaft at all. Taking the spring off can make that check easier. If you have any wiggle that you can feel, you have worn out bushings and an air leak, which will primarily show up as a lean idle. The best solution is to send the carburetor out to be rebushed. If getting the carburetor rebushed isn't feasible at the moment, a temporary work around is to plug the hole in the throttle plate. The plug can be as simple as a pop rivet. Don't plug the hole if the bushings are tight as that will make it very difficult to tune (speaking from experience).
_________________
"I like how everyone likes talking about Zeke's Thing yet he's the only one that's ever seen it." - Katie
"I've seen pictures..." - Jeremy

[rhubarbray]

I have the 34Pict 3 carb and a dual vacuum distributor. Original crank pully and it took me a lot of reading to figure out the dual vacuum method has the timing points set at 5 degrees ATDC! Not before. Threw me for a bit.
So I'm thinking I can either plug the hole on the underside of the tin or make a gasket for the block that mounts on the carb with no hole but what does that small vacuum hose connect to and is it needed?

[germansupplyscott]

[SilverThing]

Scott, your red EGR line is connected to the port on the carburetor that normally feeds the vacuum retard on the distributor. The normal EGR vacuum feed is the port that is angled upwards at 45 degrees on the flange at the rear of the carburetor (rear being the rear of the car). This is not intended as a criticism as that is a very clean looking engine, but I want to make sure people are hooking up hoses correctly if they intend to run the DVDA and the EGR.

The vacuum retard port is intended to pull full vacuum at closed throttle, while the EGR connection is only intended to pull vacuum at part throttle. Getting the two ports backwards will make for a very frustrating idle situation.

Hopefully this factory bulletin helps clarify a little:

_________________
"I like how everyone likes talking about Zeke's Thing yet he's the only one that's ever seen it." - Katie
"I've seen pictures..." - Jeremy

[germansupplyscott]

Ya good points about that hose. There is no retard on STIKGIRL's engine. No EGR technically either but some of it remains. You would need the super-rare '74 muffler with EGR port to have a complete system. And an original Thing carb.
_________________
SL

[Bruce]

[rhubarbray]

Yeah......funny you should mention that. I did that yesterday thinking mine would be ok,..........nope. I can see the play with my eyes and feel the click/click. I'm guesstimating .006-.008" play.

Sigh,......another job to the list.

Luckily I'm also the company machinist and I happen to have some oil impregnated nylon called funnily enough Nyloil. I'm going to make up a couple of bushings and see if I can make better, longer lasting bushings. Was going to use a really good aircraft grade bronze but then thought it'll just wear out the shaft.