Fuel Pump model GHN5 or GHD5

Lucky me, my fuel pump is only briefly mentioned in the Haynes manual, no picture. Does anyone have a technical picture of one of these fuel pumps? Does anyone know if they have points? Thanks. Hugh

John Twist has a video of an SU fuel pump tear down and re-build. http://www.youtube.com/user/Universitymotorsltd#p/search/0/_VGQPg15-8E

If it "ticks" it has points...the source of the ticking....

So the car wouldn't start the other day. Was dead as a doornail. Couldn't tell if it was fire or fuel. Started with fuel. The ticking of the fuel pump seems irregular. Sometime clicks and sometimes silence. Tapped on it several times here and there and still nothing. Pulled the front plug wire and tried to start to see if plug was firing. It didn't but I felt the spark. Insulated pliers must have a leak. The gap seemed a little wide .035 or so. I narrowed it to more like .030 replaced it tightened it up put the wire back on and she started right up. Now I'm really confused because I have no idea what happened or what changed to make it start. My "Scooby sense" says maybe the fuel pump. Thoughts?

Once an SU builds pressure it will stop ticking. Get in the car, turn on the switch and listen....it will go fast, slow a bit, then stop. Start the motor and the pump goes into action. There are too many variables to simple blame the pump which is known to be working...at least sometimes.

Given what you did and the result, I'd be looking at cleaning or changeing the plugs. That was the only thing that worked inspite of you intuitions contrary.

Maybe the pump, but gapping the plugs certainly had no effect on the pump....
Just thinking out loud with you...

Thanks Kirk. I thought the pump might stop clicking as it built line pressure. The plugs and wires are new (June 2010).

Hugh - If the pump is a SU pump, it ticks whether it is points style or all electronic (the all electronic is just a slightly softer ticking). The pump in your car should look like the attached picture. To check if the pump is supplying the proper amount of fuel, disconnect the fuel line at the carbs and route it into a quart jar that is marked at the 1 pint level, turn on the ignition and time how long it takes to pump one pint of fuel - it should be less than 30 seconds.

Roberts recommendation follows historical advice about MG - If you suspect the SU fuel system, check the Lucas ignition system first.
Cheers,

Check out this site:

http://www.sucarb.co.uk/

Bob

Just had it out for another test ride, drove great. However, the idle is running high (again) and the car gave out a little back fire under the hood when I turned it off. Now what?

Hugh
It's difficult to know. The backfire might be timing issue. High idle any number of things including the ZS carb...a problematic equation even when new. There is a seal in the bottom prone to leaking and/or setting the car on fire.

As you appear to be new to the forum are you also new to LBCs? A lot of folks trash the ZS in favor of the cheap fix, a down draft Weber. Others who have or don't mind a more valued investment, convert to a used manifold and tried and true SU carbs. Another option is the SU 44...single 1.75 carb equal to the ZS.

There is a lot of info on the subject of a post 74 MGB and the associated engine running problems. Perhaps a search will find you better answers. Good Luck!

Problem solved!!! The screws holding the water choke to the carb worked themselves out. The water choke was barely hanging on so I was loosing vacuum. Found the screws in the fender lip (thank you God). Screwed the water choke back to the carb, started right up and has run great for the last two days. Wow!, was I lucky. I was worried the fuel pump or carb were bad and needing to be replaced. Thankfully, it was a simple and free problem. Oddly enough, I saw a John Twist article Moss' catalog that said high RPM can be caused from the loss of vacuum when the screws to the water choke come out. That guy is a genius!