Fuel Injector Connector - *the MALE side* ?

[Rich Vandervoort]

Gm has an mid 70's car at the Milford proving grounds with many different 
connector types in it.  This car gets a few miles put on it every year and 
the resistances thru these connectors are measured every year.  The soldered 
and crimped connections have held up the best as in they have had the least 
increase in resistance over the last 25 years.  Once while talking to some 
Isuzu engineers, I was told "Packard (Weather Pack connectors) reputation in 
Japan is leak."  A friend of mine who designed wiring for bus chassis always 
oriented the connectors so the water would drain out of them.  This was 
based on previous bad experiences, not just conjecture.

Rich V.


Date: Thu, 18 May 2000 23:25:30 -0700
From: garwillis at msn.com (Garfield Willis)
Subject: Re: Fuel Injector Connector - *the MALE side* ?

On Thu, 18 May 2000 22:33:09 -0400, "nacelp" <nacelp at bright.net> wrote:

>Anywhoz,  the clip to hold the injector onto the fuel rail, and the
>"snap" ring for holding the electrical connections on are for assembly line
>abuse, to keep things together as the UAW workers assemble things.
>  How this would apply to avio use I wouldn't venture a guess.  Solid
>mounted engine and lots of vibration might be a different deal all 
>together,
>but then if that bad, I'd be soldering heat shrinking things together.
>  And to answer your actual guestion, been to several county fairs, and
>never saw em.....

Hee, dang I was hoping you HAD seen sumpin at the fair. Durn.

Seriously, I sure admire/appreciate the progress we've made with O-ring
connections and individual injector fuel-rail clips on the fluid/fuel
side. Sure makes custom fuel plumbing easier. Unfortunately, if you're
planning on inserting some trick electrics between the ECU and the
injector, you want something that's hard to wiggle loose there too. This
is an automotive app we're thinking of (shhh), not an aviation thingie,
so I'm still interested in what the UAW would do. :)

Interestingly enough, didyaknow that solder connections are
largely/actually a no-no in aviation/aerospace? What they've found thru
experience (read: crashes/failures) is that if the connection is secured
physically solid via solder connections, then at the point the solder
stops and the stranded wire begins, IF you haven't strain-relieved the
wire at that point, vibration causes the wire to break off THERE, and
not the soldered connection!

Trouble is, when you solder a connection, the solder wicks up some and
THERE is where the flexing happens, so if you just leave the connection
secured by solder, and don't strain-relieve the exiting wire, the solder
connection is fine, but the connection still breaks if vibrated. Many of
the more "emphatic" crimp connections are actually gas-tight, so what
turns out a more reliable connection is indeed crimp connection, with
strain-relief/crimp-hold on the trailing/exiting insulated wire. Hard to
believe maybe, but properly crimped spade terminals with strain relief
are really pretty good, not to mention things like Metripack and
Weatherpack connections; they're just about as good as it gets! Golly.

Solder AND strain-relief with some robust shrink or sleeving would
probly be the best, but it's not much better than a properly crimped and
finished connector, either. We use both, depending on app.

Gar


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