Steve J.

Even though my '78 euro 5spd is exempt from Texas emissions inspection, I would still like to burn clean yet simplify the set-up if possible. Does anyone know what the stock euro configuration was? Was it originally equipped with an air pump and catalytic converter? The car was federalized and EPA certified by Wallace Labs. Current set-up includes a charcoal cannister, air pump, and catalytic converter with oxygen sensor connected to the Neutronics Bosch K-Jetronic Upgrade Kit. I deleted the air pump, then learned that the Neutronics closed loop control requires the air pump. Should I remove the air pump and the Neutronics kit or put the air pump back on and keep the Neutronics kit (which I'm not sure even works)? I had intended to restore the original configuration from the factory to keep it simple. I'm sure the Germans were environmentally conscious and the original configuration burned clean enough. Would appreciate feedback from '78-'79 euro owners - What is your current set-up?

rixter

I only have an air pump, if I'm not mistaken 78-79 Euros were not factory equipped with air pump or catalytic converters, these were US importation requirements

Toejam

Mine had an air pump and resonator(which I was told housed a cat converter as well)... I deleted both since I'm in TX also.

I don't believe my car went through much in the way of federalization either, based on various bits of evidence, but who knows.

Vilhuer

Those few '78-79 euros I know have air pumps. Think only ones without were few years younger models or cars made for only certain euro countries.

Dennis Wilson

Federalizing did require the addition of the air pump and cat if they weren't already installed. The O2 sensor and modified CIS was not incorporated until 1980 on Porsches. Removing the cat and air pump will increase the HP but there is little or nothing to be gained by removing the O2 sensor, frequency valve and added fuel lines. If you must remove the O2 system and it is similar to other Porsches, the fuel lines from from the WUR to the center of the distributor will probably need to be replaced with a standard US or euro 78 or 79 model line. Also, the relief line from the frequency valve will need to be terminated or the whole return line will need replaced.

Dennis

Steve J.

If I delete the "frequency valve" (I've never heard it called that - it looks like an electric fuel injector with hoses on each end), I only need to replace the hollow screw for the fuel distributor and hollow screw socket on the WUR with the shorter stock parts.

Dennis Wilson

The frequency valve is a final adjustment on control pressure based upon the O2 sensor reading. It appears from the picture that it is installed between the WUR and the center port of the fuel distributor. On the Bosch systems if the frequency valve is unplugged from the O2 sensor brain it defaults to open, but I'm not sure on your aftermarket system. Does it still run OK when the connection is unplugged? If it does the valve could just be unplugged and the rubber control pressure relief line in your picture could also be removed and or plugged.

Dennis

Steve J.

The hoses circled in the photo are on each end of the valve which allows fuel to flow from the WUR to the fuel return line on the fuel distributor. Since it looks just like a fuel injector I believe it defaults to closed if not energized. I can't tell any difference with it unplugged. Here's how it works.

gruffalo

my 81 euro has neither cat nor air pump.
no nothing. just the k-jetronic mechanical injection, and a plain exhaust

karl ruiter

My 78 had air pump and EGR but no cat, so I had to add it, since I am in CA. If you remove the Neutronics system I would be interested in it.