My 59 XK 150 started fine in the garage, and ran about 10 miles to buy a
paper. But then it wouldn’t start again. After waiting 45 minutes for
the AAA truck (“Before we put it on the flat bed, lets try one it more
time”) it started up and I drove her home without incident. Now the
question is Why? Could that happen again, when my wife is with me?
When it wouldn’t start, there was no ‘click-click’ from the fuel pump
which lead me to believe that the pump had failed. Could be that the
pump has an intermittent problem, but I have begun to wonder - could it
have been nothing more than good old fashioned vapor lock? Would that
have caused the fuel pump problem? it was hot and the 45 minutes between
the no-start and the start was enough to allow the engine bay to cool
down.
In reply to a message from Sack, Bob sent Tue 25 Sep 2007:
Hmmm. Reminds me of my old 1965 Austin 1100. When warm it
regularly had a problem with the electric fuel pump, which usually
responded to a well aimed hit with a mallet (or even a kick - it
was quite accessible!). Not that I’d treat an XK so
disrespectfully…
Reminds me of the time my 150 died at highway speed at night, out in the
middle of nowhere in New Mexico. As I coasted to a stop on the rough
shoulder, the vibration was enough to cause the fuel pump to jump to life.
I used that new-found knowledge to get me the rest of the way home, as Mark
had done.
Gene McGough
XK-150 FHC S834515DN
XJ6C II 1976----- Original Message -----
From: “Luxo” mark_dunstan@pt.lu
In reply to a message from Sack, Bob sent Tue 25 Sep 2007:
Hmmm. Reminds me of my old 1965 Austin 1100. When warm it
regularly had a problem with the electric fuel pump, which usually
responded to a well aimed hit with a mallet (or even a kick - it
was quite accessible!). Not that I’d treat an XK so
disrespectfully…
In reply to a message from Sack, Bob sent Tue 25 Sep 2007:
Bob is obviously a gentleman that has never lived with a british
car. Those of us that have, all carry a tool of some sort to rap
on their respective SU fuel pumps periodically.
New, used, rebuilt or worn out, they all stop ticking and it takes
a licking to get 'em going again.
There are however, new pumps with the requisite 2 ~ 4 psi output
that are reliable, just not british.
I posted this info before but in case you didn’t see it…Before you start
tearing things apart check to make sure that the electrical connections to
the pump are good. In my case it turned out that the ground connection to
the frame was all rusty. Go figure why Lucas would not just ground the
frame of the pump to the car rather than have a separate ground wire. Also,
search the archives as there are electronic fixes for the old pumps. The
easiest one is a diode across the points.
My 59 XK 150 started fine in the garage, and ran about 10 miles to buy a
paper. But then it wouldn’t start again. After waiting 45 minutes for the
AAA truck (“Before we put it on the flat bed, lets try one it more
time”) it started up and I drove her home without incident. Now the question
is Why? Could that happen again, when my wife is with me?
When it wouldn’t start, there was no ‘click-click’ from the fuel pump which
lead me to believe that the pump had failed. Could be that the pump has an
intermittent problem, but I have begun to wonder - could it have been
nothing more than good old fashioned vapor lock? Would that have caused the
fuel pump problem? it was hot and the 45 minutes between the no-start and
the start was enough to allow the engine bay to cool down.
In reply to a message from Sack, Bob sent Tue 25 Sep 2007:
I’d like to hear more from the list about vapor lock…my xk has
occasionally done the same…
normally starting and running well…but when engine is fairly
hot…over 85 C…wont start…if only off for 10-20 min, then after
cooling for about 30 min more…starts right up…didnt tap on
anything…just went to get ice cream. (for me…not to put on
engine). I too was about to call for the flatbed…but decided to
try one more time.
I suspected heat to fuel problem. will the XK vapor lock…or is it
some similar heated fuel problem that may affect the line or float,
either not getting fuel…or…heating pushing too much fuel?
Pat H;
Actually, having a separate ground wire is generally more “positive” than
a “ground thru the case”… When one experiences an electrical problem, 99
times out of a hundred, the person will NOT remove a suspect item, thus
never seeing if there it corrosion impeding a good “ground” (earthing), but
will often remove the “electrical connections” (both “hot” and “earth”) to
check them for continuity/corrosion, etc.
Besides, even if an item is grounded thru it’s “case”, having a “back-up”
ground wire is cheap insurance…
Charles #677556.
Go figure why Lucas would not just ground the----- Original Message -----
From: “Pat Harmon”
frame of the pump to the car rather than have a separate ground wire.
The reason the fuel pump has a seperate ground (earth) connection on the
XK-120, resides in the way the pump is mounted.
The original mount had the pair of large steel washers cushioned by
accompanying rubber discs on both sides and on both studs. If the studs
were at all centered in the chassis bracket, the pump was effectively
insulated from it!! A seperate and good ground (earth) strap or wire is
essential.
If you leave out the rubber cushioning washers, the pump might have a
path to ground especially if you didn’t treat the mounting bracket with
Por or epoxy preservative. An intermittant ground will act like
sticking points and it will respond to the mallet whack!