How I Fixed An Old Subaru With A Shotgun Shell And A Little Backyard Wisdom

Older cars can be great fun while everything is running properly, a reminder of a time when vehicles were generally much lighter and operated on simple mechanical principles. When something is not working right, they can sometimes be downright maddening if there are no obvious clues and the problem appears to come and go without a distinct cause.

You’re probably looking back up at the headline of this story, thinking I ‘fixed’ an old Subaru by giving it both barrels and sending it to the scrappers. I assure you this is not the case.

My mum, who has had infinite patience for my predilection for filling driveways and yards with vehicles, decided during Covid that she would like an affordable classic car for occasional use.

We started scouring all the usual websites here in Australia: CarSales, GumTree, Ebay and JustCars. Initially mum was interested in either a classic Mini or Beetle, having been vehicles she had driven in her youth. A VW Beetle is the reason I exist to be able to write the occasional story for you, Autopians, it being the vehicle that enabled my parents to meet when dad worked at a local garage in the mid-’70s in northern Sydney.

With most of Australia’s population of 25 million being crammed onto the East Coast of the continent, most listings for what we were after were in either Brisbane, Sydney, or Melbourne. After looking at many dozens of listings, and even sending one of my best mates to go and inspect what looked like a really nice Mini 1275 LS, we gave up on the idea for a while as the ‘Covid Tax’ was still in full swing which was flooding the market with a good number of dubious ‘restorations’.

It was tricky to confirm authenticity via online classifieds and I had no familiarity with Minis and only a small amount of air-cooled VW knowledge thanks to a rusted-out ‘65 Beetle which was our paddock-basher growing up.

Those who followed our building of Project Cactus may know that I work by day as a farm insurance agent. Other than the fact that I get to be out of the office at least half the week compared to my prior career, which was completely office-bound, another perk of the job is finding old cars on farms, to the detriment of my savings account.

About an hour east of Dubbo is the small town of Dunedoo (pronounced ‘dunny-doo’). It’s primarily a farming community with a population just over 1,000 and a damned fine bakery.

I have quite a few clients in the surrounding area, and about three years ago on one of these farms I spotted a 1990 Subaru Brumby with around 136,000 miles.

As an added bonus it was an AgQuip edition, which was a dealer special from the late ’80s to early ’90s to promote what is billed as Australia’s largest agricultural field day. The package included some sweet stripes that changed each year, an alloy bullbar, sump guard and a full-width steel rear bumper with an integrated towing hitch.

I won’t go too deep into the history of the Brumby/BRAT as we have touched on the main highlights here at The Autopian a few times already. Available in Australia from 1978 all the way to 1994, we didn’t have the mad jump-seats in the tray (bed) as we didn’t have protectionism quite as severe as the still-going US Chicken Tax.

The farmer said the last time he drove the Brumby, he thought he may have overheated it as it conked out not far from the house and then drove badly afterward, consequently, he was willing to sell it for a very tempting price.

I checked it over and there was no milkshake in the oil or coolant, and when it started up the engine was idling smoothly with no unusual noises. Our family has had a good history with Subarus, with most people in my immediate and extended family having owned a Subie at least once.

I gave mum a call on the drive home, to see if this was something she would be interested in as I already had my 1970 Valiant Wayfarer Ute for doing ute things.

Having put Minis and Beetles on the back burner, this seemed like a good lower-cost entry into something that is becoming a classic. Mum decided this seemed like a good idea, with her moving into town in the near future a small ute would also be handy for things such as taking the dog to the vet or buying appliances.

I rang the farmer and a deal was struck, in January 2022 we went and picked up the Brumby.

Over the summer break, we gave the little red machine a good cleanup, removing layers of caked-on grime in the engine bay and blasting out years of Dunedoo dirt from the interior and exterior.

I also replaced most of the cooling system including a new radiator, water pump and hoses in an act of caution. We had the suspension replaced by a local mechanic as I ran out of time and the carburetor was sent off to be reconditioned by a specialist to ensure all was right with the vehicle and mum could drive it with confidence for a small fraction of the cost of the classics we were looking at online previously.

All seemed to be going well, we even managed to get the Brumby to one of the last screenings at the Dubbo Drive-In before it was torn down:

After a bit of use, an unusual issue would seem to come and go where the engine would fall flat and appear to run on much, much less than the factory’s rated 80-odd hp. With mum’s confidence in her little red ute failing, I had to step in and sort it out.

With some testing, I determined that the issue didn’t happen when the engine was started up from cold. Where the issue would happen was if the engine had reached operating temperature and then been driven for a decent distance, at least 16 km (10 mi) and had been turned off and then restarted. The problem was at its worst when trying to take off at an intersection, right when you need power. You could rev the engine harder in lower gears to sort of drive through it and the issue seemed to go away after a few minutes.

I went through my usual diagnostic checklist, honed from my years of experience with carbureted engines, mainly Hemi Sixes and the odd Holden ‘Red’ or ‘Blue’ Six as well as our 1300cc air cooled VW and applied it to the Subaru’s EA 81 engine.

The timing was right on where it needed to be, the cap, plugs and wires were all new. I then went to the carburetor. I initially tried disabling the choke, and this made a minor difference but ultimately was not the solution to the problem.

It would be an understatement to say that engines in the final quarter of the 20th Century struggled with meeting mandated emissions regulations whilst also retaining good driveability and power.

Look in the engine bay of anything made after early ‘70s in the US, or early ‘80s here in Australia, and the rat’s nest of vacuum hoses, smog pumps and other random baubles put fear into the hearts of many a backyard mechanic.

Later Subaru Brumbies such as ours are no exception in regard to this, with Australia having mandated all new petrol-burning passenger cars sold must run on unleaded fuel for 1986 along with a mandatory catalytic converter and tighter emissions (reaching 1975 US emission standards!).

I checked the vacuum hoses, and a few were on their way out. Replacing these hoses and the rear fuel filter by the tank seemed to again alleviate the symptoms somewhat, but it was not a cure. The carburetor didn’t appear to be boiling fuel or getting heat-soaked and the fuel system was all as per factory from what I could ascertain.

Stumped as to a solution, I went to speak to the local carburetor wizard. He goes by many names, but you can call him Tim as that is his legal name. You may remember we visited his shop while Project Cactus was being inspected so that we could head to Deni Ute Muster.

Tim is the only person I trust to tune my triple 45mm Weber DCOEs on my Charger. He can take a little while to get a job finished, but his attention to detail is second to none.

I described what was happening with the Brumby, and Tim mentioned that he has seen many Brumbies with weird issues. The factory Hitachi is what is known as a ‘feedback’ carburetor, which was common in the ‘Malaise Era’ in order to get carbureted vehicles to meet the government emissions testing. This resulted in a complicated series of solenoids and thermostats to try and keep the fuel mixture as lean as possible so that the Brumby could meet the applicable exhaust gas testing of the time.

Tim grabbed a spare Hitachi from one of his many piles of carburetors and pointed out where the two main vacuum ports were so that the solenoids could control the fuel mixture. He explained that by blocking one or both ports, the fuel mixture would stay the same as it was when cold and this may solve the issues we were having. The engine would run a little on the rich side when warm as a result, but not enough to cause any harm.

To test this, I went to the nearest tool store and bought a few needle-nose vice grips. By a process of elimination, I came to find that it was indeed these solenoids causing all the hot-start grief. With these vacuum hoses spreading like cobwebs all over the engine bay, I decided that the easiest way to fix the issue permanently was to leave the hoses in place and plug them internally.

Based on their internal diameter, I realized that a 00-size buckshot pellet could squeeze down to fit inside of the vacuum hoses.

Opening up a 12-gauge shell, I extracted a couple of pellets and used the bench vise to turn them from .33 in (8.38 mm) down to a rectangular lozenge shape of around .25 in (6.35 mm) wide.

Installed into the vacuum line just upstream of the carburetor port, this makes for a great block-off and retains the factory look.

With this complete, the Brumby is back to running at full power!

I do have access to a few Brumby parts cars and will see if I can test some solenoids to replace this fix as new parts seem to be unobtainable, but for now it means the little Subie remains a fun weekend rig and handy utility for mum.

Now that it’s had some more kilometres under the tires, we’ve noticed it uses a bit of coolant. This bypass pipe seems to be the culprit, so now I need to make a plan to fabricate a new piece.

If you’ve repaired one of your vehicles with an unusual product or item, let us know in the comments!

Top graphic inset image: Warner Bros.