July 1925 - December 1970
Gus Wilson's Model Garage
GUS TAMES A COLD-BLOODED BEAST
By Martin Bunn (John L. Bellah)
It was a crisp fall day, and upon returning to the Model Garage after lunch the ringing telephone diverted him from a clutch replacement job he intended to complete. "Gus, Jack Philpott of Stanfield Motors. We have another insurmountable problem we need to pick your brain on."
"What's the problem, this time, Jack?"
"It's a 'cold start, driveaway situation,' Gus. I tell you, these tightened Federal emission-control laws are causing us to tear our hair out." I'll send the car down with Bill Lester, our Z-Car specialist this afternoon. Maybe you two can hash out the problem as the customer is threatening to sue us, the distributor and the manufacturer. Says the car is unsafe and almost killed his wife."
An hour later a silver Datsun 240-Z arrived on the back of the Stanfield Motors tow truck, driven by gangly, red-headed, Bill Lester. After shaking hands, Gus asked; "What's the story on this one, Bill?"
Bill replied, "You know Gus, the Datsun 240-Z has been around for a couple of years, and we've had very few problems. They're like the Datsun 510--very reliable and solid cars. In fact the Z's share similarities with the 510. Independent rear suspension and the Z-Car engine is a 6-cylinder Over Head Cam version of the 510 engine."
Pausing to light a cigarette, Lester continued; "In the past Z-Cars were all four-speed manual, however this is the first automatic we sold. Cold-blooded like you wouldn't believe! Stalls, sputters, and snorts until it completely warms up. Once warmed up it purrs like a kitten, but until then...
Gus interjected, "Save me some time, what's been done?"
"More like what hasn't been done. We went through everything, set to the book! Replaced the thermostat, distributor, PCV valve, wiring. Even played around with some settings which weren't in the book. We replaced both carburetors and manifolds, just in case something was amiss with the dual carbs, or not enough exhaust heat to the intake manifold..."
"Lack of enough intake heat would certainly cause a car to run improperly when cold. What about the automatic choke?"
"No good, there, Gus. The Z-Cars have dual S-U--type carburetors, similar to British cars. They have manual chokes. And for your information we replaced both choke cables with piano wire, which is a bit stiffer than what the factory supplies--a problem we ran into in earlier models."
"Leave the car here, Bill, but I can't promise you anything."
Early the following morning Gus sat in the driver's seat of the Datsun, which had been sitting out all night outside the shop. The thermometer outside his shop read 37-degrees. Setting the choke, he started the straight six engine, backed off the choke and the engine settled to a fast idle. A few seconds later, he dropped the console shifter into "Drive" and the car promptly stalled. Restarting the engine and letting the engine idle for 30 seconds, the engine again stalled when he tried to drive off. On the third attempt the car drove off but sputtered, backfired, and surged for the first mile. Gus could very much understand that this car was dangerous. Take off from a stop light and suddenly stall in the middle of a busy intersection was an invitation to disaster. After reaching normal temperature the engine was running silky-smooth.
Gus returned to the Model Garage and has his assistant, Stan Hicks hook up the ignition oscilloscope and exhaust analyzer, noticing everything appeared normal. Timing was on the nose, and the automatic and centrifugal advances were within specs. Carburetor icing was ruled out being the problem was at start-up. Icing would occur after the engine had been running for a while. The chokes worked properly and if anything, were capable of producing an excessively rich mixture when full on. Disassembling the two carburetors Gus noted the needles were the correct type, properly adjusted, and not bent or excessively worn. Discouraged, Gus re-assembled the carburetors and for the lack of anything else, advanced the ignition timing 2-degrees and set the idle mixtures a tad richer. He then parked the Datsun outside the shop for next morning's road test.
The following morning was even colder and starting the sports car brought about the same behavior as on the previous morning. While the cold engine was idling Gus had Stan spray an aerosol can of carburetor cleaner on the theory of expansion and contraction may have exposed a loose throttle shaft, vacuum leak from a vacuum line, loose gasket or improbably, a porous manifold. Besides, Bill Lester said he replaced both the carbs and manifold. Frustrated as to not finding anything wrong, Gus had Stan grab a wrench and tightened all carburetor and manifold fittings. Gus then test-drove the Datsun, however it's behavior was little improved from the previous day. Heading for the turnpike, the sports car performed admirably. Upshifts and downshifts of the automatic transmission were within factory specs, however the engine pinged slightly on acceleration due to the advanced timing. Arriving at the Model Garage, Gus reset the timing, pulled the valve cover to check valve clearances, which he discovered were set to specs. Noticing the fuel gauge read close to empty, pulled up to the pumps and added five gallons of premium gasoline to the tank. He then parked the Z-Car next to his shop for the next morning's road test. If the engine's behavior was the same he would check the intake/exhaust manifold to see if they were delivering enough heat to properly vaporize fuel in a cold engine.
The next morning Gus seated himself in the cold sports car, set the choke and started the engine. After a few seconds at fast idle, he backed off the choke slightly, dropped it into Drive and to his surprise, the car rapidly accelerated out of his drive, having to hit the brakes when he arrived at the street. Surprisingly the Datsun performed flawlessly on his test drive. Thoroughly puzzled, Gus returned to the Model Garage and made some phone calls, one to have the owner pick up his car.
Bill Lester arrived the following morning along with a sharp-featured man carrying a cane and walked with a noticeable limp, identified as Matt Wheeler--the owner of the Datsun. Lester explained Wheeler injured his left leg in Viet Nam and purchased one of the first automatic 240-Zs when they arrived in this country.
Turning to Wheeler, Gus asked what kind of gasoline he used in his car.
"Mr. Wilson, I've always run Shell."
"Well that seems to seems to be your problem I put some gas from my pumps into your tank. The car is cold. Take it out for a spin."
Returning a few minutes later Wheeler remarked. "Well, runs fine. You seemed to have fixed it. But I don't understand. My wife's Pontiac runs just fine on Shell gasoline."
"Yes, but with a Datsun Z-Car, you're pulling a lot of power from a relatively small engine, and tuning is critical. So is your gasoline. Some cars may run differently on different brands of fuel. Gasoline is often specifically blended to compensate for the environment, and specific weather conditions. With your wife's big V-8 you may not notice the difference, but it's there. There may be a slight change on power output or rate of consumption. In some cases you may want to experiment with different brands and grades of gasoline to determine what operates the best for your car. In fact, Toyota specifically advises not to use Shell gasoline in their vehicles. It seems Shell's fuel blending doesn't agree with Japanese engines."
Bill Lester interjected; "But Gus, we never had complaints with earlier Z-Cars."
"Yes, but remember those cars had manual transmissions. One could overcome the poor running by slipping the clutch and buzz the engine up a bit. The automatics have tight converters, and under load seem to falter and run poorly at those speeds with the wrong gasoline.
ŠJohn L. Bellah, 2018