[xk] XK140 Engine Keeps Quitting

Hi All,

My car is a '57 XK140 with no modifications. It always
starts easy and runs very well - until the engine dies.
Frequently the engine simply stops running while I’m
driving. There is no backfire, stuttering, or other
indication, it just quits.

It usually happens when I am coasting downhill in 3rd or 4th
gear with no throttle applied. Then, when I apply throttle
is when I realize the engine has died. It has happened
after only a couple of miles and also after 30-40 minutes of
driving.

Originally I thought the coil was bad and I replaced it with
a Lucas Sport Coil, but the problem persists.

My roadside diagnostics include checking for spark and
checking for fuel. In the three times it happened this week
I quickly pulled a spark plug and found there was spark when
I cranked the engine, so I believe the coil, condenser,
distributor, and wires are OK.

I also found the fuel line was pressurized when I loosened
the banjo bolts at the float bowl covers. I pulled the
float bowl covers and found the floats were floating, not sunk.

Then after doing nothing but thinking for 20 to 40 minutes
and occasionally trying to start it, the engine starts and
runs normally again. I’m stumped.

When I checked the float arms with a 1/2’’ steel dowel I held
the little spring-loaded pins in the float valves fully
compressed when I adjusted the arms to 1/2’’. Is that the
right way to do it?

Winter is coming and I’m retired now, and I’d like to get
some time in on this car before the road salt season. Any
help or suggestions would be appreciated.

Sam Bell–
SBell
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–

In reply to a message from SBell sent Thu 13 Oct 2016:

No stuttering, just quits, sounds like ignition failure,
rather than fuel delivery failure.
See my thread last month entitled Ignition coil failure.
Mine would quit when it was hot and then work again when it
cooled off. But it would give a weak spark on the spark
tester light when cranking, and yet be not enough to start
the car.
But if your coil is new, try replacing your condenser. They
are cheap at rockauto.com and they also have points cheap.
Then check your ignition switch.–
XK120 FHC, Mark V saloon, XJ12L Series II, S-Type 3.0
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
–Support Jag-lovers - Donate at http://www.jag-lovers.org/donate04.php

In reply to a message from SBell sent Thu 13 Oct 2016:

Sam,

Had an issue many years ago - was a decent sized cobweb
that had fallen into the fuel tank (had been out of the
car and I didn’t cover the filler adequately to prevent
such an occurrence). It would block the outlet
occasionally and hence the fuel supply would cease.

I am not sure if the fuel line being pressurized also
means that fuel is flowing. If I waited for the vacuum
from the fuel pump to release, the rubbish in the tank
would float off the fuel tank outlet and all good until
the next time.

Best

Keith–
The original message included these comments:

Frequently the engine simply stops running while I’m
driving. There is no backfire, stuttering, or other
indication, it just quits.
It usually happens when I am coasting downhill in 3rd or 4th
gear with no throttle applied. Then, when I apply throttle
is when I realize the engine has died. It has happened
after only a couple of miles and also after 30-40 minutes of
driving.
I also found the fuel line was pressurized when I loosened
the banjo bolts at the float bowl covers. I pulled the
float bowl covers and found the floats were floating, not sunk.


Keith Bertenshaw
Rockaway, NJ, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
–Support Jag-lovers - Donate at http://www.jag-lovers.org/donate04.php

Hey Kiwi
Cobwebs, don¹t they blow off if you drive you car?
Just askingŠ.:slight_smile:
The VikingOn 10/14/16, 4:15 PM, “KeithB” <owner-xk@jag-lovers.org on behalf of keith@bertenshawworld.net> wrote:

In reply to a message from SBell sent Thu 13 Oct 2016:

Sam,

Had an issue many years ago - was a decent sized cobweb
that had fallen into the fuel tank (had been out of the
car and I didn’t cover the filler adequately to prevent
such an occurrence). It would block the outlet
occasionally and hence the fuel supply would cease.

I am not sure if the fuel line being pressurized also
means that fuel is flowing. If I waited for the vacuum
from the fuel pump to release, the rubbish in the tank
would float off the fuel tank outlet and all good until
the next time.

Best

Keith

The original message included these comments:

Frequently the engine simply stops running while I’m
driving. There is no backfire, stuttering, or other
indication, it just quits.
It usually happens when I am coasting downhill in 3rd or 4th
gear with no throttle applied. Then, when I apply throttle
is when I realize the engine has died. It has happened
after only a couple of miles and also after 30-40 minutes of
driving.
I also found the fuel line was pressurized when I loosened
the banjo bolts at the float bowl covers. I pulled the
float bowl covers and found the floats were floating, not sunk.


Keith Bertenshaw
Rockaway, NJ, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
–Support Jag-lovers - Donate at http://www.jag-lovers.org/donate04.php

I had the same fuel delivery issue with my TR3 years ago.
Not cobwebs but partially decomposed mice that had gotten into the fuel
tank.
Would intermittently cut off supply cutting engine and by the time I had the
bowls uncovered, the fuel was back.
Once I had the tank out and shock it upside down…I knew exactly what the
problem had been.
Didn`t know whether to rejoice or get sick:)

  • Brad-----Original Message-----
    From: SBell
    Sent: Thursday, October 13, 2016 3:54 PM
    To: xk@jag-lovers.org
    Subject: [xk] XK140 Engine Keeps Quitting

Hi All,

My car is a '57 XK140 with no modifications. It always
starts easy and runs very well - until the engine dies.
Frequently the engine simply stops running while I’m
driving. There is no backfire, stuttering, or other
indication, it just quits.

It usually happens when I am coasting downhill in 3rd or 4th
gear with no throttle applied. Then, when I apply throttle
is when I realize the engine has died. It has happened
after only a couple of miles and also after 30-40 minutes of
driving.

Originally I thought the coil was bad and I replaced it with
a Lucas Sport Coil, but the problem persists.

My roadside diagnostics include checking for spark and
checking for fuel. In the three times it happened this week
I quickly pulled a spark plug and found there was spark when
I cranked the engine, so I believe the coil, condenser,
distributor, and wires are OK.

I also found the fuel line was pressurized when I loosened
the banjo bolts at the float bowl covers. I pulled the
float bowl covers and found the floats were floating, not sunk.

Then after doing nothing but thinking for 20 to 40 minutes
and occasionally trying to start it, the engine starts and
runs normally again. I’m stumped.

When I checked the float arms with a 1/2’’ steel dowel I held
the little spring-loaded pins in the float valves fully
compressed when I adjusted the arms to 1/2’’. Is that the
right way to do it?

Winter is coming and I’m retired now, and I’d like to get
some time in on this car before the road salt season. Any
help or suggestions would be appreciated.

Sam Bell

SBell
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–

Sam,
Two things can be easily checked :

  • Some repro distributor rotors become conductive when hot, and cause
    ignition grounding. As soon as engine cools down, it restarts as if
    nothing had happened. Replace with good quality or NOS.
  • The distributor automatic advance counterweights can seize when hot,
    and stuck at full advance they will cause engine to stall upon
    reaccelerating. They release as soon as engine cools down, and engine
    restarts as if nothing had happened. Lubricate and see what happens.
    Some people have also been known to find funny things (rags, …) had
    been dropped in the fuel tank, and blocked the fuel flow upon
    acceleration.
    Keep us posted.
    Francis Thibaud

It could simply be a bad connection on your battery. Don’t laugh, I have
had it happen to me.

Check it and clean it and retighten.

John Brady
678462
Bedford, MA

When it next cuts out, open your fuel cap and listen for air rushing in. If that happens change your filler cap.

DJOn 15 Oct 2016, at 13:39, JBrady5282@aol.com wrote:

It could simply be a bad connection on your battery. Don’t laugh, I have
had it happen to me.

Check it and clean it and retighten.

John Brady
678462
Bedford, MA