1st scary experience for a newbie ::o

so, i have had 2 months of nearly perfect motoring after putting my 'b back on the road after almost six years of storage. all it took to get it road worthy was a tune up and carb rebuild... making me mighty smug about the rumored unreliability of british cars :)

here in new england, today was far to nice not to drive, so i picked up one of my friends and set out to find brit-bits in rye, new hampshire. after drooling over a pair of tr6's and a rough gt6 in the front lot, we headed back to haverhill. along the way, the car started bucking and chugging. i topped off the fuel with high test and crossed my fingers that we might make it home without problem. over the next few miles, the car still bucked and jerked like an ill tempered mule, back fired a hand full of times and eventually ran fine. my buddy (more of a camaro and trans am kinda guy) thought it was probably a clogged fuel filter. does this sound right? and if so, where do i go about finding said fuel filter?

What kind of carburetor do you have?

If it is the fuel filter you can get them at NAPA ( I currently have a NAPA supplied filter in my 71) or Moss motors, Victoria British ETC. As to that being the problem I will let more experienced members take it further
Cheers
Paul

Mine did similar things twice; Once the fuel filter was clogged, the other time I had a lead to the fuel pump come a little loose.

Stock '78 ?
Fuel filter is next to the firewall, inboard of the bonnet hinge.
Problem you describe could be fuel related and thats a good place to start.
May have also been that fuel pump decided to take a rest.
What were the driving conditions at the time? Straight and level, constant speed?
RS

replacing the fuel filter is never a bad idea, but remember that most fuel problems are really ignition. how old are the plugs, cap, rotor? when was the last time the timing was checked? how are the points? (if it still has them?)

Check the carb diaphragm. If you rebuilt it, then its probably okay - but a pinhole in the diaphragm could cause the symptoms you describe. Take it out and hold it up to the light and see if you can see any holes.

I'm wondering if there was some sediment in the tank that has now clogged the pump, filter or whatever.

That's why I use 2 filters - one before the pump and one before the carbs.

I think the obvious bases have been covered. I'll be surprised if it's not a fuel related issues.

Steve

Sounds exactly the same as my car. Mine had been idle for 14 months and although working perfectly it started to do as you describe and went all chuggy. The problem was my old fuel pump (the points version) which had rusted a little and just started to stick. I replaced it with a electronic pump and the issue has never arisen again.

I would put my money on the filter. Remove it take it to an auto parts store buy a new one. If by chance that doesnt do it blow out the fuel line. If it still bucks try the fuel pump. NAPA has them.

Did the car get fresh fuel after sitting or have stabilizer in it? If not, you may need a drying agent.

Test the fuel flow by putting the fuel-line that connects to the carb in to a jug and let it run (approx 1qt per minute?) The flow shouldn't sputter or start/stop. Maybe run close to a gallon or so. That would also get water IF that's the issue.

There are two things I'd consider:

1. Make sure you buy a Fram fuel filter (G2 for my MGA, same for you I think) because they're clear! You can tell at a glance if the filter is full of crap, or water, or... dry! This can really help diagnose fuel problems. You'll likely see a small amount of crud get into it, and it will never become completely full (the air pocket in my filter used to vary in size quite a bit), but it will help you a lot to see what, if anything,is making it through the fuel lines to the engine compartment.

2. There's also another problem that comes to mind. Did you know BL fitted our cars with very clever "low coolant warning devices?" ;) Yes, if the heater control valve is leaking (which could lead to low coolant level and engine damage), the heater control valve dribbles on the distributor and causes erratic running before eventual shut down. Check your distributor for coolant inside!

3. Last thing is, did you by chance go for platinum spark plugs? My Dad threw a set on his A and, even after removing and flushing the tank and fuel lines multiple times, the residual lead in the fuel system poisoned his plugs in about 20 miles and the car wouldn't run. I had an MGB that also poisoned the platinum plugs, although it took a lot longer than 20 miles because I'd been running for a years with unleaded gas. I don't use platinum plugs anymore!

Good luck, it won't be that hard to find the problem I'm sure!

Ad'm - for suspected fuel delivery problems, see the article, Fuel Delivery Troubleshooting Guide in the SU Fuel Pump Articles section of my web site at: http://homepages.donobi.net/sufuelpumps/
Cheers,

While it certainly could be a fuel problem, it could also very easily be electrical. One way to tell is to watch your tach when the bucking occurs. If fuel related, the tach will drop slowly; if electrical, it will drop like a rock to zero and bounce quickly back up as power is recovered. A good place to start, if it turns out to be electrical, is the nut on the starter where the positive from the battery attaches. If it's loose or corroded it will cause the exact symptoms you describe.

Pretty much any small clear fuel filter will work fine. Walmart has one a bit bigger than I like but it will work. The parts chains have the better, smaller ones. I try to buy 2-3 at a time and make sure each B has 1-2 spares in each bag (You DO have more than one B don't you?? :) ). If not, I will find you a nice GT to go with the roadster. Great New England car.

I'm missing one response: sticking carburettor float needle. Not sure if the 1978 has these.

Not trying to hijack this, but have a question about the crud you guys talk about in the tank. Has anyone used the POR-15 tank cleaning and sealing kit? Or anything similar? And does that help with the crud issues?
Only asked cuz my tank probably comes off next week.
Thanks,
Frank