DDoyle9570@aol.com wrote:
> Fellow shade tree mechanics.....
> This is sort of a convoluted story, please follow it all the way through
> before rushing to an answer.
[...]
Well, I don't have the answer to your problems, but maybe some of my
own past problems will spark your imagination to figure out what's
going on.
Your "Pump A" symptoms sound slightly similar the to way my original
HMMWV injection pump misbehaved. It's idle speed regulation was poor
(it would "hunt" around), and it would be slow to respond to
accelerator pedal position changes, but the engine sounded good and
didn't smoke at whatever speed it happened to like at any given
instant. Installing a pressure gauge and a section of clear tubing in
the supply line, and another piece of clear tubing in the pump's
return line, showed that the pump was getting fuel with adequate
pressure and no air bubbles, but was blowing air bubbles out the
return line. That suggested that air was getting in through the pump
body somehow, and thus the pump had some bad seals. I swapped it for a
rebuilt pump at Diesel Specialists, Inc., the local Stanadyne shop in
Placentia, CA (and one of the exceedingly few trustworthy auto repair
shops I've ever encountered, by the way), and the new pump fixed
everything up.
I'll go out on a limb and say "Pump A" might still have a leak
somewhere that's letting in air, and screwing up the speed regulation.
I'm no injection pump mechanic, so take that with a grain of salt
about as big as a 6TL battery.
The first thing I would do is to verify that the pump is getting clean
fuel at proper supply pressure, with no air bubbles. I dunno what the
supply pressure is in a deuce; it's around 4-7 PSI on a HMMWV. If you
can temporarily plumb in a piece of clear tubing on the supply side
near the pump, and also tee in a pressure gauge somewhere, then it
should be easy to see if air is getting in on the supply side, or if
the pump is getting starved for fuel at low throttle settings.
Next, I'd check all of the injectors and injection lines as a matter
of course. You might even be able to do that yourself if you're a
do-it-yourselfer who likes buying tools; I recently picked up a diesel
injector tester on Ebay, and it's not the first one I've seen there.
Does the deuce's fuel pump have a return line from the pump to the
tank? I haven't looked at mine in a while, so I don't know. If it
does, you might be able to plumb in another section of clear tubing to
see if air is getting into the pump. If it is, and it's not getting in
through the fuel supply, then it's time to send the pump to "shop 3",
IMHO.
It sure sounds to me like both "Pump A" and "Pump B" still have some
problems to be ironed out, but I'd rule out leaks, low pressure, fuel
starvation, clogged or misadjusted injectors, and clogged or leaking
lines first.
If all else fails, maybe it's time to call a licensed exorcist? :-)
I hope this rambling helps. Good luck, and please keep us posted on
whet you find!
P.S.: Your postings about a year and a half ago about buying trucks
for cheap through the DRMS inspired me to buy my own M109A3 deuce.
Thanks!
-- Mark J. Blair, KE6MYK <mblair1@home.net> PGP 2.6.2 public key available from http://www.keyserver.net/ Web page: http://www.qsl.net/ke6myk/ DO NOT SEND ANY UNSOLICITED COMMERCIAL EMAIL TO THIS SITE PLEASE SEND PLAIN ASCII TEXT ONLY -- NO HTML OR QUOTED-PRINTABLE
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