View Single Post
Old 09-17-2012, 05:36 AM   #1
black_box
DIY extremist
 
black_box's Avatar
 
Join Date: Jul 2011
Location: Brooklyn
Posts: 348
Worst mechanical disaster? (may you learn from your mistakes)

One of the constants of doing your own wrench work is that something is bound to go wrong. What's the worst crime you've committed against your car while trying to fix or improve it?

For me, it's probably the time I barbequed my intake manifold...

I was in college, and had a '96 Chevy Silverado with the Vortec V8 (back when I lived in the south and gas was less than $2). It was late fall, but in May of that year I acquired an '81 KZ Kawasaki 1000, my first real daily rider motorcycle and rode it exclusively for the summer. The truck sat for a couple of months, and when I went to start it, the motor turned over and... nothing.

Now this was my first fuel injected vehicle, and I was raised in the "better get a bigger hammer" school of auto repair so my first reaction, after checking the ignition fuse was to pour a little gas into the throttle body to get things flowing, just as I'd done on my old '77 mercury I'd driven through high school, every time it sat for more than a week.

What I didn't think of though, was that unlike a carbureted engine, this thing had a lot of flammable parts underneath the nylon intake manifold. Namely, this thing, which on the early vortec engine was called the "spider injector", basically one huge fuel injector with a bunch of hoses going to individual intake runners, barely a step up from throttle body injection.

A little gas down the hatch seemed to work. The engine fired up and ran for a few seconds, and then boom! Backfire! I went back and stuck my head under the hood, smelling burnt plastic. I went ahead and (remember, I was 20 at the time) tried to start it up again. It ran, but very very poorly, sputtering and trying to stall. I cut it off and retreated.

What had happened was that the backfire had regurgitated gasoline onto the plastic hoses underneath the intake, burning a couple of them so that whenever the truck was running, two cylinders worth of raw gas was being squirted into the manifold. After talking to dealer mechanic my dad knew, I pulled the intake off to inspect the injector, which is when I found the gas soaked burned up evidence of attempted truck murder!

Fortunately, genuine GM is cheap, and I hadn't caught the actual intake on fire so I got out of this one for about $250 in replacement parts. It turned out that the original problem was caused by a fuel pump that was on its way out. Glad I didn't learn this lesson on a Porsche!

What are some of your most embarrassing stories of automotive horror?
__________________
"Betty" -- 2000 Boxster S, Triple Black, loaded except PSM (sold to a good home)
"Veronica" -- 2008 Boxster S, Arctic Silver on Blue
"Maleficent" -- 2007 Cayman S, Red and Black, TPC Turbo 3.6L 460 RWHP, H&R RSS Coilover / TPC stage 2 suspension
black_box is offline   Reply With Quote