2a backfire/ rough running and stall.

[Xavie]

HI guys. I bought a 2a a while back to learn a few skills on and to enjoy driving. It ran well for a couple of months and has the original 2.25 petrol donk.

Just before I moved house and became really busy it started to run rough and basically became unusable. The engine back fires some times and when you put your foot down on the accelerator it just dies. I just took it down the road and in low range it will move but come to a slight hill and say goodbye. It took me two tries at getting up this hill. The engine died a couple of times trying to go up.

It will idle fine as long as the choke is on a little however it does not like to much.

Now... please realise I have no idea about mechanics and everything I have learned has been done by reading here. When someone mentions a part I generally look in rave or google to find out what it was 'cause I really have no idea. But... that's why I'm doing this, to learn. Please be patient though.

So my ideas are possible fuel pump issue, fuel filter needs changing, ?carby.... what else could it be?

I'm not sure where to start.... I don't understand why it would back fire if it is the fuel pump though but as I said I don't really know much about any of this.

Thanks in advance.
Xavier.

[Fusion]

Hi Xavie , It might pay to see if the timing is out as well . make sure the distributor has not come lose and moved . Uncle Ho should be able to set things right for ya ;).

EDIT: might pay to check leads and spark plugs too. And give the air cleaner a good cleaning ;)

[dandlandyman]

Sounds like an inlet air leak. Either carby/manifold gaskets or maybe vacuum advance diaphragm/hose. Could be brake booster if fitted.
Timing may be out, through wear or loose bits. Try doing a valve clearance check if all else fails. Hope this helps (at least, more than it confuses...).

Dan.
69 2a 88" pet4, 74 3 109" pet4, 68 2b FC pet6.

[Xavie]

I can see I'm going to have a lot of reading to do, lol. But that's okay. It's also the tools which are an issue. I don't have many. But once I can figure out the best way to buy them I will.

Xav.

[JDNSW]

The fact that the choke improves it suggests strongly that it is a mixture or fuel supply problem. Likely causes are:-

1. Dirt or water in the carburetter, blocking passages or jets.

2. Intake manifold or carburetter loose or with a damaged gasket.

3. Partial fuel blockage, carburetter union filter on a Solex carburetter, strainer in the water trap on the fuel pumps, or the strainer on the bottom of the tank pickup pipe.

4. Fuel pump sick - dsiconnect pipe from carburetter and operate the hand priming lever under the pump. If it gives a good flow, then the problem is not a fuel blockage or pump problem.

5. It may not be fuel - these symptoms can be mimicked by an ignition problem, usually the points having closed up, but possibly the condenser or even the coil, or a bad connection in the ignition circuit.

There are other possibilities, but these are the most likely.

John

[Blknight.aus]

Cmon guys lets start simple for the bloke.

Go buy a can of Areostart or Brake/carby cleaner from supercheap or wherever

take the aircleaner horn or aircleaner off of the carby and eyeball down with the choke in the off position you'll see 2 butterfly valves. The top ones the choke the bottom ones the throttle.

if its air induction after the throttle your going to have problems heres how to find them

1. put the aircleaner back on and start it up, get it to idle as smoothly as possable as slowly as possable use the choke, a little throttle whatever it takes.

2. spray areostart around EVERY joint on the air intake side of the engine where a hose or fitting could carry a vacume or air pressure and connects to the carby below the throttle or on the manidfold itself. Dont forget you need to do the whole line and all its connections as well INcluding the Vac advance on the dizzy and the brake booster if its fitted. If you have a vac leak then you will notice a difference in running when you spray the culprit area it might take a couple of seconds if its a weepy gasket joint but it will happen. Dont ignoe the major joints between carby sections the carby adaptor plate OR the inlet manifold to head as well.

Next up is a timing/spark problem.

First things first is the dizzy loose ? grab it and twist (pay close attention to where it is first incase it does move) if it moves thats not good and will need fixing.

next start it up and get it idling smooth and slow, put on some DRY leather riggers gloves and shake all the HT leads off of the dizzy, any difference? push the end conectors on wiggle them, pull them off a little then push them back on on both sides of the lead. IF one makes a lesser difference than the other then you have a dodgy lead or plug.

If you have a known good spare plug open its gap to about 5mm and connect its body to a good earth on the motor (the rocker cover bolts are tops) with the engine off take one lead at a time from the plugs connect it to that plug then (not mandatory but it will let you look at the plug and what the engine sprays out of the plug hole the odd one out is the problem child)before you start it up remove the plug from the engine that doesn have a lead on it. when you start it will run rough but you should get a nice fat blue spark on the test plug on top of the motor. replace the plug, lead and repeat for all plugs.

Next with the engine stopped take the dizzy cap off, dont unplug the leads just unflip the catches look inside is there any dust or track marks inside that look like carbon? is the rotor button on correctly if you turn it by hand does it move in one direction and then spring back a little when you let it go? is the spring point in the cap ok (its the pin in the middle that points down from the center) if you take a small screw driver and pull back the small leaf like spring on the points (theres only one in there and it has 2 small "buttons" on it) does all the wiring in there look secure?


With out going into too technical terms that'll give you a good grounding, if its none of them then the odds are that its internal to the carby or the fuel supply itself (doubtfull it starts and runs so fuel is getting to the carbys needle and seat).

All of those check can be done with just the tools that used to come with a series landrover. spark plug spanner a couple of screwdrivers and the most common open enders (3/8 7/16, 1/2, 9/16th inch).

let us know what you find out and we'll help ya narrow it down. If your not sure of some of the parts or where to find them eyeball the howthingswork website and type in the part name your interested in.

cheers.

[Xavie]

Thanks for all the replies. With the manuals and what you have said I should not have much problem getting through this stuff. It seems wrong to be pleased that it was having issues but I'm looking forward to jumping in there tomorrow and seeing what I can find.

I do miss driving it though.

Xavier.

[Scouse]

Xavier, as you seem keen to learn what goes on with your cars, may I suggest you obtain a copy of the Readers Digest Book of the Car.

It's quite old now but it makes it very easy to understand the operation of the various systems that a car uses.
The first half explains the operating priciples, the second half goes into diagnosis & repairs.

I'm sure your local library would have a copy, if not I can lend you mine.

[Bren]

Hopefully you have solved your problems by now. I had the same problem with my 2a the start of the year. I renewed the spark plugs, leads and then set the timing. Not hard just read the book. It solved the backfiring. The fuel system problem I put on a Stromberg carby with a variable jet and works like a dream. The motor never misses a beat now. One handy hint I read on a post was if you think your carby jet is blocked with crap, rev the motor up and with a cloth in hand put it over the intake. A bit dangerous but start with low revs until you get used to it - it works a treat.
Cheers
Bren

[Blknight.aus]

a note on that rag on the carby trick...

It works but dont use a rag, they will occasionally get sucked into the carby and can cause damage especially if it manages to get sucked past the carby.


Use a thong and no, not the kind your wife might wear to bed if your a lucky boy but the kind that goes on your feet.