Dolomite 1300 - Running issues; advice please!

[garycox]

Hi all

I’ve been using this daily for a few months now and covered 2,000 trouble-free miles.

 

It has, however, developed an issue with loss of power. It’s difficult to describe but essentially at higher speeds/revs it’ll intermittently lose power in “surges” getting progressively worse until it gives up.

It idles fine once started but can be difficult to get going again if it’s cut out  rather than being switched off properly.

I’ve replaced:

- fuel filter

- all fuel lines in the engine bay

- fuel pump

- coil

- ignition leads

...and it seems to have made absolutely no difference.

I really need it to be working by Friday; any suggestions?!

[Cavcraft]

Can only guess at duff plugs (breaking down under heat) or fuel evaporation. No pipes a bit close to the exhaust and have you tried new plugs as a matter of course in case the old ones are playing up?

[garycox]

Haven’t tried new plugs; the ones in it seem okay but I guess it’s fairly cheap to try that anyway - I only haven’t because I also need to buy a plug spanner as I have no sockets deep enough!

Don’t think there are any fuel lines close enough to the exhaust for that but, again, a good thing to check!

[320touring]

Condenser?

[lanciamatt]

Stuck float in carb,? 

[garycox]

The float moves freely and fuel seems to be getting to the carb okay (there’s not much en route that isn’t new!)

 

Condenser seems a popular suggestion; will probably try that next..,

[320touring]

Good luck- they seem to be a fairly common failure point nowadays

[SiC]

What condenser is on it? Cheap ones are almost guarantee to fail. They'll take the points out with it. 

[SiC]

I'd check fuel flow too. Might have the pump starting to fail. 

[wuvvum]

When it loses power, is it a partial loss or is it as if the engine's been switched off?  In my (admittedly limited) experience a failing condenser tends to produce the latter effect.  If it's a partial loss it could be fuel related - might be worth bunging out for a cheap electric facet pump off eBay and bunging that in to see if it makes a difference.

[Tamworthbay]

Is the carb clean? For the first few months with me it needed weekly clean out sessions even with the filter, it would collect a very fine sludge in the bottom of the float bowl. Use seemed to solve it but worth checking (it stood a year before I recommissioned it, then I ran it a year before SF had it from me).

[SiC]

If you remove the petrol cap, does it help and/or let air in after a run?

[garycox]

Wuv - it’s significant; not quite “engine off” but not far from it.

 

TB - I’m crap at carbs so haven’t fiddled with it; if it’s foolproof to check it’s worth a look I guess though; the float bowl’s definitely clear but I’ve not opened the “main bit”.

 

Petrol cap off’s a free check at least...

[garycox]

SiC - I’ve just replaced the pump and no change... no idea what condenser’s on it but will change that too if I can pick one up tomorrow 

[purplebargeken]

Usual culprit for this type of thing is coil or condenser breaking down as mentioned. I had the same issue with one of my 1300 Dollies and a 110 land Rover.  I tend to run a decent Lucas 'sports' coil. 'Lecky components may be new but still shite.

[SiC]

Is there fuel still in the filter when this happens?

[Mr_Bo11ox]

Does it still have points or an elec ignition? I'd be straight on the points if it still has em.

[Three Speed]

I'd also suspect the coil. I imagine it may have a ballast resistor as I think Triumph were in the habit of fitting such things in the 70s. You could try shorting it out for a while and see if the problem goes away. 

[garycox]

Still points - worth a try!

[garycox]

SiC - yes, still fuel in the filter 

[SiC]

4 minutes ago, garycox said:

Still points - worth a try!

I reckon it's the condenser. 

The distributor doctor one is the only modern one worth having. 

This: https://www.moss-europe.co.uk/condenser-lead-25d-high-quality-gsc111hq.html?assoc=534797

(Other suppliers are available)

[SiC]

I made a video that basically explains the problem with the cheap ones:

More details on this page: 

http://nonlintec.com/sprite/cap_failure/

[barrett]

Easy way to check is to put your hand on the coil after its happened. If the coil is hot it's been put under extra load or is breaking down which is probably a side effect of the condenser failing: coils don't tend to just give up, but condensers often do and this can have a knock-on effect on the rest of the ignition system. I'd try and find an NOS condenser and coil and swap both at the same time as no modern items are as good as originals in my experience.

[garycox]

Might have to make do with whatever I can find locally tomorrow - but then will track down a decent one ASAP.

[bunglebus]

Don't think it would cause the problem you describe, but it's always worth checking the oil in the dashpot on the SU carb too.

[garycox]

Dashpot oil is present and correct 

[captain_70s]

New points and condenser would be my first point of call. Even if it transpires it isn't them a spare set is always hand to chuck in the glovebox.

 

Doubt it is vapour lock, that is usually at its worst when the engine is idling hot and the fuel flow is lessened. 

I would say that don't always rule out a component once it's been replaced. I've had brand new starter solenoids and fuel pumps be DOA.

[garycox]

FUUUUCK

So, we’ve now changed all of the above plus the condenser, rotor arm and plugs.

Seemed like it was working but has got as far as Cuckfield (from Hayward’s Heath) and has died again. Exactly the same problem.

It’s now being towed home by a friendly man who was passing on a tractor.

AAARGH!!

[GBJ]

You may find that the points have closed up or something.

[purplebargeken]

Good call re: points gap.

The fuel pump is pumping out a goodly amount of go juice is it? Have you taken off the dome bit on t he fuel pump to check the fine gauze filter?