First breakdown

[Funkin Go-nut]

Well I had my first breakdown in my 126 this week, left me stuck in the middle of rush hour traffic in norwich (Some people are so impatient btw )

Anyhoo the car runs absolutly fine when cold and starts first time , when it gets a little hot or after it has run for a bit it starts to bog down, then it starts to back fire and lose power, eventually it will stop and will not re-start.

If you let it cool for a bit it will run, but then the process repeats..

Its running an electric fuel pump and there is good pressure all the time

The carb is only a year old and I have checked and cleaned it through.

The coil is 6 months old

Plugs are a month old

Its running a mini electronic ignition kit.

Timing is about spot on (maybe ever so slightly retarded)

I have stripped most things down and cleaned them, and all looks ok, does anyone have an idea what teh problem is/what I should look at next?

Thanks  

[Darrell]

You running that fuel from the electric through the mechanical pump or have you disconnected and by-passed the mechanical pump?

Sometimes coils quit when they warm up with these new electronic ignition set-ups as they supposed to produce more black magic or something.

[Rusty's Uncle]

This is always a tricky one but in your case with an electric fuel pump and electronic ignition then even more baffling. How does that mini ignition square with a 2 cylinder engine ?
You could try giving it a good run when you have time on your hands . When it packs up do a check for spark and fuel at the plugs. Have you done a compression test ?

[Funkin Go-nut]

Hi Rusty and Darrell, thanks for the responses

The mechanical pump has been taken out of the fuel system.

I havn't tried a compression test when hot as I dont have a gauge, I will see if I can get one tommorow.. (could compression be lost with an increase in temp?)

Can you explain what you mean by "Square with the engine"?

Obviously something is failing when it gets hot, and it doesn't take long for it to cool enough for things to start working again...

The coil does get hot, but I put this down to its location in the engine bay (Over the exhaust)

[Darrell]

In these instances is to look for two basic errors.

Lack of spark or lack of fuel.

I doubt compression would be anything to concern yourself with.

It is the classic symptom of the fuel pump problem but if you have removed that then I'd have to say go back to basics, induce the problem and check for spark and fuel. that means lead off with a plug attached and held with insulated pliers against the block, fit a hose to the pump outlet into a bottle away from the hot engine to see if there is petrol.
Have someone hold the bottle while ignition/pump is switched on, and just to well and truely cover my butt have a fire extisguisher ready and do this in a well ventilated area etc etc.

Just seen Rusty's reply so we say basically the same thing although I have found my compression goes-up a little when it gets warm.

[Funkin Go-nut]

Well I took it to my local garage and they set everything up properly and road tested it and all seemed fine...until I took it to work again and the same problem occured.

Its deffinitly getting worse and once warmed will only drive 2-3 miles before stopping..If you leave it 10 mins it will fire straight away.

The garage has it again and I now have another burn on the back of my hand from where I removed the dizzy cap and caught it on the exhaust.. Not good working on these engines at 2am..

Hope this gets fixed soon as I had to buy another car to keep me mobile for work, at least it has a 1 and a 6 in its name..and its italian 

[nrg19uk]

Try a new coil and condenser I had similar problem and this sorted it

[Hazey-n-Marc]

Or the tank might be rusty, flakes of rust pick up and block the pipes after it's been shaken a bit.

[Draigflag]

Sounds similar to my problem which i plan on fixing in the spring summer!

Let me know if/when you get it fixed what the problemo was.

[dajwid]

Condenser. thats my guess.

[Funkin Go-nut]

Coil is new(ish), and electronic ignition so no condenser, plenty of fuel pressure as well...

[dajwid]

Only really leaves Carb then.

[DEYAN IYI]

If the clearance is less than normal, when hot, the valves can't close properly. Then compression leaks and the fresh mixture backfires in the exhaust (or in the inlet manifold). And starting becomes harder.

Maybe something's wrong with the fuel pressure when hot. If there's too much pressure in the hose, and the needle can't hold it, it will flood the carb before the next start.

[Funkin Go-nut]

Well so far so good, I have just been on a 20 mile drive and all seems well  

Had a mixture of town, a and b road and a dual carriageway blast as well.

I have:
converted to twin coil ignition
Fitted a ballast resistor
replaced the dizzy with a new one and re-set the timing
Fitted new points
Changed the plugs to irridium tipped ones
Changed the plug leads
Cleaned out the fuel lines, electric pump and changed the filter
Cleaned out the carb again
Blasted a can of carb cleaner through the engine while running
Flushed the engine, changed the oil, added some upper cylinder head treatment, run the car then drained the lot out and put in fresh oil.
Put a bottle of nitrox hot shot in the fuel tank.

Seems to be running really well now, got it up to temp and working hard with no loss of power or failures....

Fingers crossed its ok now