Vacuum Leaks Suck: 1985 Chevy S-10 Blazer vs 1987 Isuzu P’up Spacecab

Welcome back! Today we’re taking a visit back to the bad old days of feedback carburetors, and looking at two otherwise-cool trucks that are suffering from carb problems and/or vacuum leaks. Which one is worth untangling the black spaghetti for? That’s what we’re here to find out.

Yesterday I gave you a tough choice between two cool vehicles. Both cars had lots of fans, and several of you said you’d take both if you could, but in the end, the big tall Mitsubishi took home the win. Score one for sport, and utility.

I think I agree, for what it’s worth. I do love those old Volvos, but it occurs to me I already have a car with a pushrod 1.8 liter four, a four-speed stick, and twin SUs. Do I really need another? I mean, I don’t need an upright Japanese SUV either, but I have a feeling I’d get more use out of it. And I did really love our old Nissan Pathfinder.

Now, those who are too young to remember the malaise era might not realize what the real villain of that era was. It wasn’t catalytic converters, or the switch to SAE net horsepower ratings, or five-mile-per-hour bumpers. No, the face of true evil in those days was the electronic feedback carburetor and all the miles of vacuum hoses connecting it to various power-sucking emissions devices like EGR valves and air-injection pumps. Take an already lean-running engine, give it a vacuum leak, and you’ll want to drive the thing off a cliff, only you can’t, because it won’t stay idling. Or has no power under acceleration. Or something.

Both of today’s trucks are so afflicted, I’m sorry to say. But knowing that they’ll both need a weekend of replacing every hose and gasket you can think of, we can assess the rest of their respective merits and see which one you think is worth the trouble.

1985 Chevrolet S-10 Blazer – $3,500

Engine/drivetrain: 2.8 liter overhead valve V6, four-speed automatic, part-time 4WD

Location: Chico, CA

Odometer reading: 80,000 miles

Operational status: Runs and drives, but hesitates unless you floor it

I have always had a soft spot for the two-door S-10 Blazer. It’s such a clean design, and it’s just the right size, practical, and tough. The only thing that could have made it better is a removable rear section of the top like the old full-size Blazers had. The sweet spot for these came a couple of years after this one was built, when the 4.3 liter V6 became available; these 2.8s were a little anemic, especially with an automatic. But I can only feature what I find for sale, so we’re stuck with the small motor.

Fun fact about the 2.8 liter V6 in these: You access the oil filter through the driver’s side wheel well. A cup-type filter wrench, two long extensions, and a ratchet, and it slips right out above the left front tire. The rest of the truck isn’t quite so easy to service, but it isn’t terrible either. If this Blazer were one year newer, it would have throttle-body fuel injection, but sadly this one is fed by a two-barrel carb, which seems to be the cause of most of its running woes.

It could use a little upholstery work too, but I haven’t seen a mid-Eighties GM product with a perfect interior since the mid-Eighties. Even with a rip in the seat, I remember these as being pretty comfortable inside. Sadly, that comfort is somewhat compromised by non-functional air conditioning. The seller, of course, claims that it only “needs to be recharged.” Uh-huh.

The paint’s a little faded, but I don’t see any rust. And it’s two-tone! We need more two-tone cars. I mean, more color variety in general would be good, but two colors on one car? Now that’s living.

1987 Isuzu P’Up Spacecab – $2,800

Engine/drivetrain: 2.3-liter overhead cam inline 4, four-speed automatic, RWD

Location: Hemet, CA

Odometer reading: 155,000 miles

Operational status: Technically runs and drives, but has brittle vacuum and fuel lines

Isuzu was always kind of an also-ran in the small truck wars. After years of selling Isuzu pickups as Chevy LUVs, Isuzu brought over its trucks under its own name to compete with Chevy’s S-10. Years later, the roles were reversed, when Isuzu sold a rebadged S-10 as the Hombre. In between, Isuzu pickups were known by the adorable contraction “P’up.”

Every small truck maker sold an extended-cab variant, but Isuzu’s “Spacecab” was special. Not only was it extra long, it was extra tall as well, with a raised roofline for a couple extra inches of headroom. Every little bit of room counts in these small trucks, and the taller roof probably made the inward-facing jump seats in the Spacecab almost livable.

The P’up is powered by Isuzu’s 2.3-liter overhead cam four, in this case backed by an automatic transmission. Automatics are rare in small trucks of this era, especially Japanese trucks, and I know some of you are rolling your eyes in disgust right now. But for a little runabout truck, it doesn’t really matter that much. It will be a little sluggish, but it will still haul stuff home from the garden center just fine.

Or it will, once you replace a bunch of perished rubber vacuum and fuel lines under the hood. This truck has been off the road for a while, and as you know, cars don’t like to sit. Rubber hoses get hard and brittle, and while imminent failure of vacuum lines will ruin your day and cause drivability issues, potential fuel leaks are dangerous. At least they’re not high-pressure lines, since it’s carbureted.

These days, we take easy starting, smooth idling, and hesitation-free acceleration for granted. Fuel injection is a wonderful thing, and it has now been thirty years since the last carbureted vehicle was sold in the US – coincidentally, an Isuzu pickup. But plenty of old carbureted cars are still running around, and that means the dark art of carburetor tuning, including tracking down vacuum leaks, is still good to know. And vacuum hose is still available by the foot at any good auto parts store. So which one of these is worth the hassle of sorting out?

(Image credits: Craigslist sellers)