Tab Julius wrote:
> Well, I just tried to make it up to Stowe for the British Invasion and
> it gave me a lot of grief.
>
> The engine seems to be running, just doesn't have anything to propel it.
>
> It's exactly the same feeling when you run out of gas (how the engine
> behaves).
>
> Sometimes coming off the gas (or cresting a hill) makes it recover.
>
> If driven moderately, as I did coming home, it can be avoided.
>
> If driven aggressively (giving it an "Italian Tune-up", I think it is
> called), it's much more likely to trigger the condition.
>
> Once triggered, it will recur intermittently for the rest of the trip.
>
> When it's happening there will be "surges" where it seems to get the
> fuel it wants, and leap forward, then it seems to be starved again.
>
> My gut tells me this is fuel-related. I would think an electrical
> problem wouldn't exhibit quite this collection of behavior, but I could
> certainly be wrong about that.
>
> If someone can describe an electrical condition that would behave like
> that, I'm happy to listen, because I'd rather diagnose an electrical
> problem than a fuel problem, but it doesn't seem to strike me as one.
It sure sounds to me like intermittent fuel starvation, but I have had
exactly those symptoms from an electrical fault. The wee ground wire in
the Mini's distributor that grounds the rotating plate to the diz body
had come un-spotwelded; when cruising, it ran fine, but as soon as I
tried to accelerate or run up a steep hill, it would start to sputter
and gargle and would lose power dramatically. I have seen similar
behavior from other causes of high voltage breakdown, including a duff
coil and shorts to ground.
As I suspect you are aware, it takes a lot more energy to fire the mix
under load than it does while cruising or idling; if the electrical
system isn't delivering full power, it can cause ignition failure when
under load. This usually will NOT show up when doing the normal spark
tests and in most cases won't affect the idle.
One of my habits when troubleshooting intermittent failures that won't
fail completely is to wait until full dark, and then open the bonnet and
have a friend run the engine up and down while I watch the engine area
in the dark. You might be surprised at how many cars that are "running
just fine" prove to have visible sparks at the coil nose or the
distributor or plug wires when observed in the dark. Fixing this will
add power.
Don't stand exactly in line with rapidly rotating parts; I have had two
acquaintances die from thrown fan-blades.
-Rock http://www.rocky-frisco.com
--
"JJ Cale Live" CD & Video: http://www.rocky-frisco.com/calelive.htm
The Wednesday Night Science Project: http://www.wednitesciproj.us
Larry Spears and the Hapless Romantics: http://www.larry-spears.com
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