Lately, it seems like a lot of people I know are Getting A Good Car (Back) On The Road. An acquaintance--
far from a car buff--traded his Smart Fortwo for a Scion iQ. Maybe not a
brilliant move, but at least a move in the right direction. My cuz is restoring a Triumph TR-6. And Hotshoe Wannabe is getting his 1981 VW Scirocco back on the road.
Hotshoe originally intended to turn the Scirocco into an Improved Touring wheel-to-wheel race car. He stripped the interior, installed a short-thow shifter kit, replaced the lower front A-arms, and upgraded the suspension bushings. He also had a VWOA experimental camshaft installed, and a valve job done. But time and Hotshoe moved on. So he's returning it to street trim to put it up for sale. He kept the Scirocco's exterior and interior trim, so reversing a barely-begun IT prep would be simple screwdriver-and-wrench job, right? Wrong.
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| It would have made a fine IT race car in the early 1990's. Now it will make a fine retro hot hatch. |
When he reinstalled the upgraded cylinder head and started the engine, he got a loud rapping noise from the #1 cylinder. Uh, oh... After much double-checking of timing, specs., and clearances, he discovered that the shop that had done the head work had used the old (stock) valve clearance adjustment shims. The clearance on the #1 exhaust valve was
way too loose; the others were all too tight. When he properly re-shimmed the new, rorty, camshaft, the rapping went away. The engine now ran OK at idle and low speeds.
But...
The fuel filter was leaking and the engine would not rev beyond mid-range. Hotshoe suspected a bad fuel pump. He removed it and found caramel-colored liquid inside and coming from the tank. His
a-HA moment arrived: the car sat for ten years with E-10 ethanol gas in the tank. The results of partially draining the tank are shown in the pictures below the one of the pump.
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| The a-HA moment: caramel-colored gas which, allowed to evaporate, showed solid precipitates. |
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Above and below: what the gas drained from the tank looked like when run through a coffee filter. The residue is a
slurry at first, but, when allowed to dry, forms a solid precipitate. Similarly, in a fuel system allowed to sit for long
periods of time, the ethanol will absorb atmospheric H2O and also evaporate, leaving behind a milky residue. This
"goo" will eventually harden into a solid that cracks into tiny pieces that must be physically removed from the system
before the engine can be made to run properly. |
To thoroughly drain (and clean) a Scirocco fuel tank, it must be removed from the car. This requires partially dropping the exhaust system and rear axle. If this is beginning to sound like a "for want of a nail, a shoe was lost..." story, that's about the way Hotshoe feels. He hopes that once he has the tank, pump, and accumulator back in business, he can blow the rest of the system clean with compressed air. After all, the car started and ran before this adventure began. On the other hand, there are a lot of places for slurry/precipitate to hide:
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The fuel accumulator is adjacent to the pump, so replacing it and the fuel filter are no big deal. Of more concern is
the condition of the fuel line from the tank to the engine, the fuel distributor, and the injectors. The system must be
free of contaminates because VW's injection system operates at 35 p.s.i. at the pump's output side to maintain enough
pressure to feed the injectors properly and return unused fuel to the tank: enough to loosen residual crud. |
Hotshoe is about to leave on a family vacation. And of course there's more going on in his daily life than rebuilding the fuel system of his Scirocco. He hopes to have it fully apart, examined, cleaned, and reassembled by August-ish. I'll blog his progress.
Further notes on ethanol gasoline:
I park my Mustang, mostly, from November to April. It's not stored; it goes out for short warm-up runs when the roads are salt-free. I fill the tank and add Sta-Bil in October. (I dump an entire, small, bottle of Sta-Bil into a tank that's less than half full before pumping gas, to thoroughly mix it. This is, roughly, a X2 "dose" compared to Sta-Bil's per-gallon recommendation.) The average winter mileage is about 275. In early spring, I add a half-tank of new gas as early as possible. In summer (when I do not use Sta-Bil), it is not unusual for a tankful of gas to last 4-6 weeks. I've not had a problem with fuel delivery or starvation or rough running at high revs or full load. It's a happy car, as far as I can tell. But I recently switched fuel brands from one that "may contain up to 10% ethanol" to one that has none. In Illinois (and some other States), gas pumps must be labeled with the percentage of ethanol. But the amount can vary within a State, and within the same brand. If you want to minimize or avoid ethanol, the best practice is to check the pumps in your area and use the brand that shows the lowest content. But keep checking the pumps.
Fuel stabilizers are claimed to impede/retard "phase separation," in which the heavier ethanol-as-it-absorbs-water tends to settle to the bottom of the tank. The most common brands are Ethanol Shield, Fuel Guard for Ethanol, Star Tron Enzyme Fuel Treatment, and Sta-Bil fuel stablizer and/or Ethanol Treatment.
Here's an extended quote on additives from an article by Dave Searle in the April, 2013, issue of Motorcycle Consumer News (thanks to Hotshoe): "Sta-Bil Ethanol Treatment claims to contain petroleum distillates that prevent the ethanol from combining with water so that it resists dropping out of suspension [in the gasoline], and a water remover that helps to keep the water in an emulsion of particles small enough that it can be burned. It does not contain any alcohol, but it does contain chemicals that will absorb water, although not as much, they tell us, as will isopropyl or methyl alcohols. It's intended as a preventative, rather than a cure for already separated water/ethanol. In fact, we were told that is is virtually impossible to produce a product that, in small quantities, will be able to re-suspend separated water/ethanol."
