RE: Re: RE: Re: turn truck off but still running

From: Bernd D. Ratsch (bernd@texas.net)
Date: Sun Nov 24 2002 - 09:45:44 EST


I totally agree with Jim. Once the key is turned off, the fuel pump
turns off as well (no more fuel). However, there still is pressure in
the lines. This pressure is enough to supply fuel to an injector if
it's leaking, dirty, or just stuck in a slightly open position
(needle/seat).

The gas-tank fuel injector cleaner may work, but highly recommend having
a shop run the professional strength stuff though the fuel rail.

Other things to check (along with the fuel injector cleaning):

Bad plugs, carbon buildup in the combustion chamber (causing hot spots
that can reignite fuel dripping into the chamber), or the smell of fuel
after the engine has been turned off.

Don't rule out the electrical problems though...checking the above
mentioned stuff is the easiest (and basic check).

- Bernd

-----Original Message-----
From: owner-dakota-truck@bent.twistedbits.net
[mailto:owner-dakota-truck@bent.twistedbits.net] On Behalf Of Jim Miller
WB5OXQ
Sent: Saturday, November 23, 2002 10:55 PM
To: dakota-truck@dakota-truck.net
Subject: DML: Re: RE: Re: turn truck off but still running

REPLY
This would only be true on a carburated engine because the fuel in your
truck does not pass through the throttle plates, only air passes
through. This is a called a dry manifold. Fuel is injected at each
intake port by an injector that is electrically operated. Pulses are
sent to the injectors by the engine computer and are timed to the
opening of the intake valve. You must have a voltage feedback problem
somewhere in the truck or a faulty ignition switch. Voltage feedback
problems can be caused by a bad ground, leaky diode in the alternator or
some relay sticking. There is also the possability of an injector not
shutting off the fuel when it no longer receives a pulse from the
computer and there is still pressure on the fuel rail for a short time
after the fuel pump is turned off. I still believe this to be an
electrical problem and I have seen it on other veichles a few times, no
make in particular either. I know it is late at night and possably more
members will see your post tomarrow and offer their suggestions. Jim in
Waco



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