EFI VK Conversion

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Page created by T Nov 14th 2005:

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EFI VK Engine installed in an HZ Kingswood. Click to Enlargen. Photo by T.

Installing VK EFI Injection Into an HZ 6 Cylinder Kingswood Wagon:

Data on the EFI VK 3.3 Engine

EFI VK Inlet Manifold, Fuel Rail, Injectors and Cruise Control Diaphragm. Click to Enlargen. Photo by HRPanelvan.

The Choice of Engine:

EFI VK Engine installed in an HZ Kingswood. Click to Enlargen. Photo by T.

Because the EFI VK 3.3 engine is a modified red/blue/black engine I didn't have to change a single aspect of the drive train from the front of the Bellhousing rearward (gear selection, speedo drive, gearbox mount, prop-shaft). EFI VK onto 161 Red EJ  

This image shows the Blanking Plate used to cover the Fuel Pump cutout. Click to Enlargen. Photo by Mingo.


Accelerator Pedals. Note the eyelet at the top of the HJ style unit. Click to Enlargen. Photo by HQ_SS.


The Sump has been removed from a blue 3.3 Engine that has been removed from an EH Holden. Note the Pickup Tube and how it's attached. Click to Enlargen. Photo by WastingEH.

This link has circuit diagrams HJ-UTE's EFI VK Conversion. As the conversion progressed it seemed as if GM had planned this as a retrofit. Because no mechanical changes were necessary to the car, no Engineer's Certificate was necessary. Only a NSW RTA Blue Slip - the same as if the replacement engine was the same type as the original. The ancillary equipment from the original engine was transferred straight from the old to the new engine. There was an abundance of parts available for this and they were dirt cheap too. A complete inlet manifold cost me less than the price of a Stromberg Carburettor.

Front view of the Commodore Engine Bay. Click to Enlargen. Photo by Hot308VK
Top view of the Commodore Engine Bay. Photo by EJ Jake. Click to Enlargen.
EFI VK Injection on 161 Engine. Top view of the EJ Engine Bay. Note the Engine has the incorrect Oil Filler Cap fitted. Click to Enlargen. Image by EJ Jake.
What the setup may look like when you come to buy it. Click to Enlargen. Note the positions of everything.

EJ Jake's 161 EFI VK Conversion 

Considerations During the Planning Stage:

Engine Performance:

The EFI VK 3.3 Engine is a significant increase in power over other blue/black Engines. The oil flow to the Timing gears is improved, the Coolant flow through the block is improved, the Pistons were beefed up and the Crank was re-worked. The head featured improved intake port shape and sodium filled, backcut exhaust valves. Stainless steel headers were fitted from the factory. If you lock the car in Second Gear (Trimatic) the Front End will get very light under full power. In the sheds there are examples of EFI VK 3.3 heads being fitted to Red Engines. It's best to take into consideration the improvements to the injected engine if you intend to make it deliver maximum power. When increasing the power of a car it can often be advantageous to lower the diff ratio in advance of the change since this type of power can destroy the higher ratioed diffs.

Fuel Economy:

Changing the diff ratio will prepare the car for the Engine's extra power which means that the Fuel Economy will be improved rather than worsened.


The EFI VK 3.3 Engine was only ever sold new coupled up to a Trimatic. It's wise to make sure that the gearbox you plan to use can handle the extra power.

The Sump and Oil Pick-Up Tube:

Commodore engines have the sump bulge at the front. Photo by SleakVH. Click to enlargen.
A critical first consideration in this process is fitting the proper sump to the Engine. Since any Red/Blue/Black 6 Cylinder Sump and Oil Pickup Tube will fit on any Red/Blue/Black 6 Cylinder Engine it makes it easy to fit the EFI VK 3.3 Engine to an old Holden. It's vital that the proper sump be matched to the car so that the steering gear doesn't foul and so that adequate clearance exists between the bottom of the sump and the Front Cross-Member. If the Engine is being fitted to an HQ, then fit the HQ sump and HQ Pickup Tube. If the destination car is an HZ, then it's vital to fit the HZ (or even the WB) 6 Cylinder sump and Pickup Tube to the VK EFI 3.3 Engine.

Purchasing the Engine:

 I bought a whole used engine complete with harnesses and all ancillary equipment. That gave me the best chance of identifying every component. The used Engine was exchanged for a fully reconditioned long Engine. I developed a close liaison with the supplier of the reconditioned Engine so there would be no mix-ups. I gave them 6 weeks notice for delivery and prepared paperwork that would follow the Engine from the first order through the entire build stage. The paperwork included all the industry rumours as well as specifics of the build. I had specific concerns that the valve lifters should be genuine GM. GEM Engines, as the company was called then, did a superb job. They listened patiently to my concerns, rang me over any confusing issues and gave helpful advice on even little concerns like who would provide the dipstick. They described the Engine as EFI VK 3.3 with WB Conversion. I wanted the extra capacity that the WB sump provides as well as the cutaways in the sump which make access to the Torque-Converter bolts easier.

Length and Height Measurements:

This image shows the height of the manifold above the rocker cover. Click to Enlargen. Photo by Phillip Gard

Inlet Manifold:

The Inlet Manifold which stands tall compared to Engines that previously only carried a single barrel Stromberg Carburettor. You may need to fit an extension to the bonnet to accommodate it. If you plan to fit VK EFI to a blue motor with air con, you will most likely introduce an angle grinder to the rear of your alternator at some stage during the conversion! This is because the EFI inlet manifold intrudes the alternator's space (photo soon) -RedWagon

Exhaust Manifold:

The Exhaust Manifold may conflict with other equipment mounted on the car. Exhaust manifold compatibility list (compatibility with EFI inlet manifold): Pacemaker PH5008 Extractors - compatible without modification (not compatible with EGR port)

Planning the Work:

Allowing plenty of time for a Conversion is a big help if the destination car is a daily driver.

Getting Approval:

Ensure that the Government Motoring Body in your State won't have particular requirements that you may not be able to meet. ====Deadline:====Before the car is pulled off the road to get the new Engine installed, a lot of the running around and seeking advice can be done more easily without the stress and pressure of a deadline. Don't leave yourself with a car that can't be driven because it needs a $1 clip that is temporarily unavailable.

Do the Ancillary Work First:

The most Convenient first step is to source and fit the Fuse Box. It will be much easier to manage the many Electrical Connections if they are contained inside the proper Fuse Box. The Electrical load on the car's system will increase. The Fuel Pump alone will draw 8 amps. Follow the recommendations under Electrical on this page. ==Starting Work:==It's the Wiring, Plumbing, Throttle connection and Emissions that take up the most time. These items can be done to the car while it is still in its original form. It's possible to drive around with the new Fuse Box fitted to the car and to add cabling to it on a part time basis. Because the Air Flow Meter and Air Filter Assembly needed to be mounted behind the OS headlight the cabling and Canister had to be relocated. The cabling was relocated to the new Fuse Box and the Canister was mounted on a special bracket that moved it slightly towards the NS. Brackets had to made to mount the Air Flow Meter and Air Intake. I mounted these directly behind the OS headlight and out of the slipstream to avoid getting mud in the manifold as mentioned in the Trimatic Traps Section. The Fuel Pump mounting bracket should be mounted well in advance of the engine swap. The Fuel Filter mounting bracket should be mounted well in advance of the engine swap. The Fuel Line should be run and secured well in advance of the engine swap. The existing exhaust system can be cut and connected to the extractor system by wrapping tinplate around the connection until the car can be driven to an exhaust place.

Throttle Cable:

Fitting the an EFI VK 3.3 Throttle Cable to an HZ Kingswood was only about half an hour's work.

The Bulk Head Fitting:

Fitting the cable through the bulkhead was easily achieved by gently filing the square entry hole to the right diameter to accept the EFI VK 3.3's cable. You can make things needlessly hard for yourself if you over file this hole so steady as you go.

The Accelerator Pedal Connection:

The crimp at the accelerator end of the EFI VK 3.3 cable is the same idea as a Kingswood, it's just twice the size. Filing it down to fit the Kingswood's split washer and rubber grommet was fairly easy to do. ===The Throttle Body End:===The cable will bolt straight up to this and adjust perfectly if the other 2 steps in the Throttle Cable section have been followed precisely.

The Fuel Supply Pipe:

There are differing views on this. I chose to run a separate rubber 300 psi line all the way from the pump damper to the fuel rail damper since the RTA indicated they had no problem with doing it that way. Other people may choose to manage their Fuel Supply Line differently.

The Fuel Return Line:

There are differing views on this. I used the existing Fuel Supply Line because it presented to the Engine's metal return pipe from the Fuel Regulator in the ideal location. The Fuel Return Line will need to be tapped into one of the Vapour Separator Lines below the Vapour Separator next to the Fuel Tank.

Vapour Canister:

This had to be retained for street use. The Canister had to be relocated and was mounted on a special bracket that moved it slightly towards the NS. I chose to leave its feed pipes alone.


The Engine is a heavy item but it can be changed in tens of minutes. Remove the original engine with everything on it. Fit the new long Engine as bare as possible, this will give you the best access to everything. Then start adding parts to the Engine that are hardest to access first. ==Injectors:==Send them away for a performance report. Have them ultrasonically cleaned and a subsequent report generated for them. ==Fuel Pump:==Send it away for a performance report. Replace it if it doesn't come up to performance level.

Cooling System:

Fitting the VK Thermostat Housing and Cover was a must because they have been designed to allow the Fuel Return Line to pass between them and the Rocker Cover. The Heater Hoses had to be routed from the NS of the Engine instead to make connection to the VK connections. I used the VK top hose because the Top Radiator Hose connects to the engine on a 45 degree angle rather than horizontally as in the HZ.


It is vital to remove the Battery Positive Terminal before removing the Connector from the EFI Computer. Simply unplugging the Computer without isolating the battery first will blow the Computer.

Wiring Diagram:

A wiring diagram for the Engine, Computer and Fuse Box is invaluable.

Engine Harness:

A critical part of the system is the engine harness. The harness has been manufactured with braided earth shield connected at the Computer end. It's best to source this second hand, complete and in good condition. Some posters have found the Computer connector to be defective so examine it for bent pins cracked connector or the retainer clip or screws missing or busted. Its probably a good idea to remove all the excess VK cables and connectors from the EFI loom if you are going to keep your factory harness. Alternatively, you could combine the two harnesses to create a single 'everything' harness for your car. If you are hooking up the harnesses separately, you will need to create an intermediate harness for connection between the two harnesses containing an ignition positive, tacho feed (negative side of coil) and starter solenoid positive. Its also a good idea to use a connector for the fuel pump positive.

Electrical Test Meters:

Investing in a quality Digital Voltmeter will give you accurate readings if you need to check the resistances of any of the sensors. Cheap Analogue meters (the type with the moving needle) load the circuit they are measuring and give less reliable readings. Since the system uses both sensitive electronic devices and a set of Injectors that are ideal devices for generating electrical spikes, it is imperative that good electrics be used. Though the system has strong tolerance for slow variance in the Supply Voltage and all the associated electronics' leads are shielded, using a high capacity battery with a high capacity alternator, clean and greased battery leads with supply cables and Earth leads in good condition is good insurance against difficulties. There are a massive number of problems that can be created in a system like this if a small battery, inadequate alternator, corroded battery terminals and inadequate leads and earths are used. Better to bite the bullet and keep all these in fine condition than run all round town trying to find out why the car isn't running as it should. Electronic systems thrive on Power Supplies that hold their outputs steady. The internal tolerance for voltage fluctuations can only go so far and it's better to prevent than cure so any potential for a blown Computer through poor battery terminals is better fixed up front. Keeping all the electrical connections in good condition is also advised. Items such as the battery earths should also be kept clean and tight. Further tips are available under The Electrical Section


A low maintenance (no screw caps) battery of 520 CCA or higher will ensure the system will get the voltage it needs across a range of circumstances.


An 85 Amp or higher alternator will be able to manage the operational transients of the system and keep the battery charged at the same time.


The same distributor as WB,VC,VH is used but the mechanical advance is reduced. Using an earlier Breaker-Point ignition is not recommended since Points-Bounce will cause erratic firing of the Injectors. The Coil Negative lead is critical in the EFI VK 3.3 system because it is the only source of timing for the EFI Computer. Static ignition timing with this distributor 12 degrees. It is only the VK 6 Cylinder Electronic Spark Timing Carburettor version that uses a Starter Plate or Flywheel mounted Crank Angle Sensor.

The Tachometric Relay:

Connections for this are part of the Engine harness. The supply for all the EFI components including the Fuel Pump are turned on and off by this relay.

Fuel Pump Warning Light:

Provision can be made to fit a Fuel Pump Warning Light for fast feedback on a Fuel Pump problem.

Pre-Start Checks:

Only 14 pins of the Computer Connector are used meaning that the pre-start checks are easy to do.

Spares Kit:

If you plan to take your car any distance you'll save yourself a lot of headache by putting together a kit of replacement parts. Having the part with you is so much better than waiting for a Towtruck in the rain. A metal carry case with a spare Fuel Pump, Damper, Ignition Module, Temperature Sensor, Throttle Position Switch, an Injector, a Regulator, Multimeter, Tachometric Relay can give you a lot of peace of mind if you are going into a remote area. Having them on hand as spares can get you going very quickly giving you time to shop around and maybe save some money on the replenishment part.


The Gregory's VK 6 Cylinder Manual has a brief section at the back on the EFI VK 3.3 but it contains priceless images and data as well as invaluable pre-start and troubleshooting checks for when the installation part of the Conversion is complete.

EFI VK Air Flow Meter Mixture Adjustment. "The mixture was too lean, so I needed to turn the wheel inside the Air Flow Meter 1/4 of a turn anti-clockwise". Click to Enlargen. Photo anf info by Mark Berner


EFI VK 3.3 Rocker Cover. Note the additional mounting Hole for the Throttle Cable. Click to Enlargen. Image by Mark Berner. 
EFI VK 3.3 Inlet Manifold showing the angle of discharge of the Injectors. Click to Enlargen. Image by Stuntman Mike. 


HX Kingswood with EFI VK Conversion. Click to Enlargen. Image by Stuntman Mike. 


The lower right hand Bolt Hole must be grounded for the ECU to work reliably. Photo by. Click to Enlargen.
Shows the Blanking Plate covering the Fuel Pump Cutout as fitted to EFI VK 3.3 Engines. Photo by Farmingoldholdens. Click to Enlargen.


The ECU and Tachometric Relay are mounted under Bonnet. Photo by HJ Paul. Click to Enlargen.


K.A.E Tachometric Relay. Photo by HJ Paul. Click to Enlargen.


The Return Line has been tapped into the Top of the Fuel Tank. Photo by HJ Paul. Click to Enlargen.


A VL Fuel Pump has been fitted to this EFI VK Conversion. Photo by HJ Paul. Click to Enlargen.


Cold Start TVS (yellow device). This needs to be removed and have the Dipstick fitted. It is glued in and is removed by twisting with a Spanner then pulling out. Click to Enlargen. Photo by HJPaul.



Wiring Diagrams:

Campbell's Shed  


EJ Jake's Thread

VK 3.3

VK Workshop Manual

Campbell's Shed

High Idle Speed Problem

Mark Berner's Shed. Mixture Adjustment

HJ_UTE's Shed

Stuntman Mike's EFI VK HX Kingswood Conversion

Sammy's EFI VK Conversion 

HD Ute's Shed



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