Thanks a lot blake, and also thank you to everyone else who has replied.
the saga continues.
I got up this morning, and tried to start the car. No joy. Once more the
fuel pump was not working. The car is a 79B, so i can get at the +12V line
from the boot, and have to get under the car to check the ground. I realised
this morning (when i read through my brand new offical shop manual) that i
had mis-read the haynes manual the other week, and that the ground lead
would be under the car. I got under the car and checked out the ground lead
which sure enough was actually there, and connected properly. So we can
discount that misinformation on my part. Sorry!
The +12V lead has an additional connector attached which runs to a little
blue plastic thing which is bolted to the chassis by one of the bolts which
hold the cover box for the pump in the boot of the car. I preseuem this is
simple a capacitor to block RF intereference from the pump. The spade
connectors were very messy, covered in some nasty black oily gunge. I pulled
off the connectors, soaked them in nail polish remover, and scrubbed them
with a toothbrush. I reassambled everything, and the pump is now working.
I had also thought of the filter in the pump, but i don't have jack stands
here at my girlfriends house! so pulling the pump off the car isn't really
an option. The fuel filter in the engine bay is clean as a whistle.
I also checked the coil like other people suggested (thanks!), and it was
cool to the touch. (It was suggested that if there was a short in the coil
it should get hot to the touch).
My worry is that there may be a more sinister problem lurking in the pump.
or possibly in the ignition system. (my main reason for this is the fact
that the car didn't die on the road, it simply wouldn't start yesterday).
And i have to drive the 140 miles back to Davis.... so I am hoping that i
can get a mechnic i know down here to check the car over tomorrow morning
before i have to set off home. It just seems foolhardy to drive that
distance on busy freeways without being certain that i have actually cured
the problem.... or am i being a fusspot?
any further advice very much appreciated.
cheers
thanks
Joe
-----Original Message-----
From: Bullwinkle
To: mgs@autox.team.net; Garner, Joseph P.
Sent: 5/29/00 5:22 PM
Subject: RE: wierdest starting problem. help!
Joseph:
I don't know what you've checked, but consider this.
On some older MGs there is a screen filter on the end of the fuel
line inside the fuel tank. I understand that early MGB's used
the MGA tank which does NOT have this filter. However, there may
be one.
Fuel Pump ground: The fuel pump is usually isolated from the car
by a rubber mount to cut down on the noise. If the ground wire
is missing, the only ground the pump has is through the metal
fuel line! This of course isn't designed for this purpose,
especially if there are fuel filters, and rubber hoses in the
line.
There is also a dome shaped filter screen under the dome of the
inlet side of the fuel pump if it is a 200 series pump.
I can't tell from my carb book, but there may also be filter
screens in the carbs also. The early H4's or HD4s have them
under the banjo union. It is a thimble shaped screen. However,
I can't find any for the HS4 or HIF carbs.
If you have low fuel delivery problems, it will agrivate vapor
lock problems.
Blake
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