94 XJ40 fuel pump stopped working. Here is what I have so far.
Load tested battery: Good 12.96 volts constant
When I turn the key on: 12.01 volts to fuel pump for initial prime
(about 3-5 seconds), then drops to zero.
When cranking, the voltage to the fuel pump connector varies
between 10.3 and 10.7 volts.
I am convinced the fuel pump is defective however, thought I would
tap this plethora of knowledge before replacing it. Any thoughts or
suggestions will be greatly appreciated.–
Ray94XJ40
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
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Hi Ray.
Try jumping the terminals in the fuel pump relay base (pins 30 and 87 the
ones that form a ‘T’ ) to see if the pump will run continously. If it does
then the fuel pump itself should be ok.
From previous posts from Bryan N I recall that the fuel pump is reliant on
the O2 sensor relay being good as well so that would be my next port of
call.
Regards Robin O’Connor
'92 XJ40 4.0 Ltr
Auckland NZ----- Original Message -----
From: “Ray94XJ40” bckamloops@aol.com
To: xj40@jag-lovers.org
Sent: Saturday, July 28, 2012 11:53 AM
Subject: [xj40] Fuel Pump Not Working
Greetings.
94 XJ40 fuel pump stopped working. Here is what I have so far.
Load tested battery: Good 12.96 volts constant
When I turn the key on: 12.01 volts to fuel pump for initial prime
(about 3-5 seconds), then drops to zero.
When cranking, the voltage to the fuel pump connector varies
between 10.3 and 10.7 volts.
I am convinced the fuel pump is defective however, thought I would
tap this plethora of knowledge before replacing it. Any thoughts or
suggestions will be greatly appreciated.
Visit the Jag Lovers homepage at http://www.jag-lovers.org for exciting
services and resources including Photo Albums, Event Diary / Calendar, On
Line Books and more !
Visit the Jag Lovers homepage at http://www.jag-lovers.org for exciting services and resources including Photo Albums, Event Diary / Calendar, On Line Books and more !
In reply to a message from Robin and Maureen O’Connor sent Fri 27 Jul 2012:
Robin,
Thanks for the information. I’ll give that a try later today and
report the findings.
Ray–
The original message included these comments:
Try jumping the terminals in the fuel pump relay base (pins 30 and 87 the
ones that form a ‘T’ ) to see if the pump will run continously. If it does
then the fuel pump itself should be ok.
From previous posts from Bryan N I recall that the fuel pump is reliant on
the O2 sensor relay being good as well so that would be my next port of
call.
Visit the Jag Lovers homepage at http://www.jag-lovers.org for exciting services and resources including Photo Albums, Event Diary / Calendar, On Line Books and more !
In reply to a message from Ray94XJ40 sent Fri 27 Jul 2012:
I went through this a few years ago with my 94’.
Under the battery rack in the trunk is the connector for the fuel
punp power. In my case the connector burned up to the point that
current flow was not the greatest.
Check the connector. If it shows signs of heating up, replace it
with a high temp connector.–
The original message included these comments:
When cranking, the voltage to the fuel pump connector varies
between 10.3 and 10.7 volts.
Visit the Jag Lovers homepage at http://www.jag-lovers.org for exciting services and resources including Photo Albums, Event Diary / Calendar, On Line Books and more !
In reply to a message from Ray94XJ40 sent Sat 28 Jul 2012:
Robin,
Here it is, 7 August and am now able to finally work on this issue.
I jumpered connectors 30 and 87. The jumper wire did heat up rather
quickly; but no response from the fuel pump. I replaced the pump
and am still in the same situation. I have tried to find
information on the 02 sensor relay you mentioned and have been less
than successful. Any informtion will be greatly appreciated.
Thanks,
Ray–
The original message included these comments:
Try jumping the terminals in the fuel pump relay base (pins 30 and 87 the
ones that form a ‘T’ ) to see if the pump will run continously. If it does
then the fuel pump itself should be ok.
the O2 sensor relay being good as well so that would be my next port of
call.
Visit the Jag Lovers homepage at http://www.jag-lovers.org for exciting services and resources including Photo Albums, Event Diary / Calendar, On Line Books and more !
In reply to a message from Ray94XJ40 sent Tue 7 Aug 2012:
If the jumper heated up quickly, there’s a short to ground
between relay and pump. Take the carpet off the front wall
of the trunk (boot) and follow the blue & black wires that
end up on the big plastic top cover. About half-way along,
you’ll probably find a burnt area connecting the two wires,
I think the burnt component once was a capacitor that
helped suppress radio interference. Cut through it and tape
both wires up. Jumper the relay and see if the pump runs now.–
The original message included these comments:
I jumpered connectors 30 and 87. The jumper wire did heat up rather
quickly; but no response from the fuel pump. I replaced the pump
and am still in the same situation. I have tried to find
Visit the Jag Lovers homepage at http://www.jag-lovers.org for exciting services and resources including Photo Albums, Event Diary / Calendar, On Line Books and more !
In reply to a message from Ray94XJ40 sent Tue 7 Aug 2012:
19 Aug and problem seems to be resolved. What appeared to be a fuel
fault was actually an ignition fault. I gave up on troubleshooting
and to it to the mechanic. Seems the ignition coil wire on the
distributer cap had failed. When the weather was dry, I got
adequate spark to fire the engine up. When it was raining, the
humidity caused an inadequate spark to start the engine. Again, a
simple remidy to a perplexing problem. Replaced the distributor
rotor, distributor cap, and coil wire.–
The original message included these comments:
I jumpered connectors 30 and 87. The jumper wire did heat up rather
quickly; but no response from the fuel pump. I replaced the pump
and am still in the same situation. I have tried to find
Visit the Jag Lovers homepage at http://www.jag-lovers.org for exciting services and resources including Photo Albums, Event Diary / Calendar, On Line Books and more !