Understanding the 35 158 Part for Your Porsche 914: What You Need to Know

If you own a Porsche 914, you know that keeping it on the road sometimes requires tracking down specific OEM part numbers. One such number, 35 158, often comes up in discussions among enthusiasts. This article explains what the 35 158 part is, why it matters, and how to go about finding a correct replacement for your car.

What Is the 35 158 Part for the Porsche 914?

The part number 35 158 corresponds to a throttle body or throttle linkage component used on certain Porsche 914 models. Specifically, it is the throttle body assembly for the 1973-1974 914 2.0L models equipped with the Bosch D-Jetronic fuel injection system. The number 35 158 refers to the original Porsche part number, which may also be listed as 914.110.111.00 or similar superseded numbers. It is a critical component that controls airflow into the engine based on accelerator pedal input.

Function of the Throttle Body

The throttle body houses a butterfly valve that opens and closes in response to throttle cable movement. As the driver presses the accelerator, the throttle plate rotates, allowing more air into the intake manifold. The D-Jetronic system then adds the correct amount of fuel based on airflow and other sensor inputs. A worn or malfunctioning throttle body can cause poor idle, hesitation, surging, or stalling.

Compatibility: Which Porsche 914 Models Use Part 35 158?

This part was designed specifically for the 1973-1974 Porsche 914 2.0L with Bosch D-Jetronic fuel injection. It is not used on earlier 1.7L models (which had a different throttle body) or on later 1975-1976 models that switched to L-Jetronic or other systems. If you own a 1973 or 1974 914 with the 2.0 engine, the 35 158 throttle body is likely the correct unit for your car. However, verify your VIN and engine type before purchasing.

Interchangeability

Some later aftermarket or replacement throttle bodies may be cross-referenced. For example, Bosch rebuilt units or aftermarket alternatives like those from German OE suppliers may use different part numbers but fit the same application. Always check the bolt pattern, throttle shaft diameter, and vacuum port locations. Genuine Porsche 35 158 throttle bodies are becoming scarce, but several specialist suppliers offer refurbished units.

How to Identify a Genuine 35 158 Throttle Body

When shopping for a replacement, look for these identifying marks:

• Stamped or cast "35 158" on the throttle body body (often near the base).
• Porsche crest or part number 914.110.111.00 may be present.
• Two-bolt flange pattern with center-to-center spacing of approximately 70 mm.
• Throttle shaft diameter of 12 mm.
• Vacuum port for the idle control valve (located on the side).
• Bosch D-Jetronic throttle position switch attached (if present).

If the part you’re inspecting lacks these features, it may be a substitute or incorrect model. Test fitment is recommended before installation.

Sourcing a Replacement 35 158 Part

Because Porsche no longer manufactures this throttle body, you’ll need to rely on NOS (new old stock), refurbished units, or used parts in good condition. Here are practical ways to find one:

• Porsche Parts Specialists: Companies like Pelican Parts, 914 Rubber, or Stoddard NLA may carry rebuilt throttle bodies or core exchange programs. Call them with your VIN and ask for part 35 158.
• Specialist 914 Wreckers: Several dismantlers focus on Porsche 914s. They often have tested used throttle bodies. Check their inventory online or call.
• Porsche Enthusiast Forums: The 914 World forum and PCA (Porsche Club of America) classifieds are good places to find parts from fellow owners. Post a wanted ad and be specific.
• eBay (caution needed): Use with care. Look for sellers who show clear photos of the stamping and describe the part as tested or rebuilt. Avoid untested parts unless you can inspect personally.

What to Look for When Buying Used

If you buy a used throttle body, check that the butterfly plate moves freely without binding. Look for excessive wear on the throttle shaft bushings (brass or plastic). Worn bushings allow vacuum leaks and erratic idle. Also check that the throttle position switch (if included) clicks properly. A rebuilt unit with new bushings and a clean butterfly will be more reliable than an untouched 50-year-old part.

Installing the 35 158 Throttle Body

Replacing the throttle body on a 914 2.0L is a straightforward job, but it requires attention to detail:

1. Remove the air cleaner housing to access the throttle body.
2. Disconnect the throttle cable from the linkage.
3. Unplug the throttle position switch connector.
4. Remove the two bolts holding the throttle body to the intake manifold (use a 10 mm socket).
5. Lift off the old throttle body – a gasket may stick; clean the mating surfaces thoroughly.
6. Install the new gasket (OEM or aftermarket) and position the new throttle body. Do not overtighten bolts to avoid warping.
7. Reconnect the throttle cable and adjust free play (usually 1-2 mm of slack).
8. Reconnect the throttle position switch and check that it activates at the correct throttle opening (typically closed and just off idle).

After installation, start the engine and check for vacuum leaks around the gasket. Adjust idle speed and mixture if needed.

Final Recommendation

For owners of a 1973-1974 Porsche 914 2.0L, the 35 158 throttle body is a vital part that should not be neglected. If yours is leaking, sticking, or causing driveability issues, replacing it with a genuine or properly rebuilt unit will restore smooth acceleration and idle. Because original parts are hard to find, buy a refurbished unit from a reputable 914 specialist that includes new bushings and a tested throttle position switch. This approach offers the best balance of reliability and value. Avoid generic aftermarket throttle bodies, as they rarely match the D-Jetronic system’s requirements. With the right part, your 914 will run as Porsche intended.