The AJ Engine Refresh

A Whole New Engine Type

1979 VW Super Beetle FI Engine
July 4 2017 – Original stock 1979 VW Super Beetle FI Engine

When I purchased Murbella back in 2017, it was my first exposure to a Type 1 Engine with the original Bosch L-Jetronic Fuel Injection System.  Of course, I had known that VW went to FI in 75 to try to deal with the ever growing US emissions regulations. I’ll admit, every single thing I’d read as I prepared to purchase the car was relatively negative. However, it was negative from the perspective that 1) it was a system that did not really allow for any adjustments and 2) that given it was an early FI system, replacement parts are not readily available. (Only VW of America went to the FI. With the rest of the world sticking to the carbs, that meant even less FI engines out there to need parts.)

For the most part, Murbella had been very well maintained by her previous 2 owners.

As you can see from the above pic, the engine was completely stock, with only the usual maintenance parts (plugs, HT leads, etc.) replaced over the 38 years. Everything else, including much of the hoses, were original.

Key differences include, but are not limited to:

  • Different Cylinder Heads – Cylinder Head Temp Sensor
  • Different Fan Shroud – Venturi Ring on intake, placement of air output vents
  • Different Manifolds – Fuel Injector ports
  • Different Air Filter – Significant differences, with attachements for various air throttle sensors and intakes
  • Integrated Throttle/Intake Plenum
  • Different Fuel Pump – Electric Fuel Pump – AJ engine block has no capability for mechanical pump
  • Additional Wiring for the Fuel Pump and the grounding
  • Different Front and Rear Tins
  • Different Cylinder Head Tins
  • Different Thermostat – temp range is different from 74 and earlier engines
  • Different Oil Filler
  • Auxilliary Air Valve
  • Pressure Regulator
  • Different EGR Filter Valves
  • DVDA Distributor
  • Different Main Wiring Harness
  • Additional FI Wiring Harness
  • ECM (In Parcel Area)
  • Different Muffler
  • Different Rear Apron


Just popping the decklid presents you with something that looks familiar but at the same time so very different.

Since her purchase, I’ve been tuning her regularly and have replaced her vacuum hoses and such with brand new parts. A lot of her rubber parts and seals, as well as her tar board firewall, have seen better days but I’ve kept them as-is while I researched and learned more about L-Jetronic Fuel Injection Systems as well as all of the variances from the 74 and earlier 1600 engines.

I will say that she’s been extremely reliable. Other than having to learn how the circuitry works on the fuel pump (the wiring harness itself is different), she has reliably started up for 2 years now without an issue. I try to start her every 2-3 weeks for 30 minutes at a time during winter to keep up fluids flowing and burn off any moisture.


The 2019 AJ Engine Refresh

Sometime in Autumn of 2019 I plan on finally dropping Murbella’s engine to fully inspect and clean it, as well as repair and replace a variety of parts to ensure she remains as functional as possible.

The agenda currently includes:

  • Carefully photo documenting the setup from every angle and for every part/connection (if it exists online I sure cannot find it)
  • Carefully disassemble down to the long block
  • Clean and repaint all tins, including the fan shroud and thermostat flaps
  • Clean, inspect, and repair (if needed) the FI wiring harness
  • Clean and inspect the alternator
  • Send our the Fuel Injectors to be professionally inspected and cleaned (replace if needed)
  • Clean, inspect, and repair (if needed) the air filtration and mass air sensor system.
  • Replace the following parts with new:
    • Fuel Injector O-Rings
    • All fuel lines on the FI array
    • Points and condenser on the distributor (convert to electric ignition if possible)
    • Air hoses
    • Vacuum lines
    • Main Crank Seal and Flywheel O-Ring
    • Push Rod Tubes and Seals
    • Intake Manifold Boots
    • Spark Plugs
    • Wires
    • Belt
  • Remove the heater boxes and exhaust pipes and muffler. Have bead blasted and ceramic powder coated.
  • Remove, inspect, and clean the Cylinder Heads. Replace only if needed.
  • Inspect pistons. Replace only if needed.
  • Snake camera into block and inspect crank and cam to document state of them.
  • Remove, clean, and inspect flywheel.
  • Replace clutch, pressure plate, and throw-out bearing.
  • Replace gland nut bearing.

With the engine out, and before putting it back in, the following will be done:

  • Replace entire firewall tar board
  • Replace engine to body seals
  • Replace decklid seal
  • Lower transmission and replace front and rear mounts

Probably 50 solid hours of work at the minimum if done full-time. That means I’ll probably have to take months to get it all completed.

What is very sad is that there’s no real easy way for me to start the engine outside of the car, given the significant differences of the FI systems versus setting up the stand to do carb engines.

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