The Triumph Dolomite Club - Discussion Forum

I am problems with an engine on a 1500HL, basically if you rev it and then let it idle, the engine struggles, then gets back up to idling speed. I can get the same effect by turning on the headlights. The battery is very weak and I can only turn the engine over with the help of another battery which came off an XUD engine.

Would a weak battery cause these symtoms? Can I try connecting the other battery to the engine? It is from an 1.9td XUD diesel, and is a bigger battery than the little Dolly one. Would it damage the Dollys electrical system?

Is this when Cold or Warm?

What's the normal Idle speed?

I wouldn't imagine it would be anything to do with the battery as that's not "powering" the engine in any way.

Most likely you'r idle speed is either a little to low if this happens when warm.

If this happens when cold, then perhaps it just needs a bit more choke.

It is happening when it is warm, tried mucking around with engine timing and carbs. Think we have cracked it and next time same issue. Very frustrating.

Your battery either needs a proper charge, or replacing. Check the voltage with a multimeter. Also, check the voltage while running to make sure the alternator is doing its job, should show 13.5 with the engine at idle iirc.
Engine struggling when extra load is applied to the alternator would suggest it's goosed, or you have an incorrect fuel mixture.

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1978 Sandglow Dolomite 1850HL The Lolomite - MOT pass! (broken again in 55 miles though...)
It's 106 miles to Chicago, we've got a full tank of gas, half a pack of cigarettes, it's dark, and we're wearing sunglasses.
Hit it.

My guess is fuel mixture, the volt meter gives a reading of 13 volts or there abouts. I have taken the battery out and put it on a battery charger. Last time I did this I used a low charge setting, bit afraid of destroying the tiny Dolomite battery. This time I am going to give it the full beans and see what happens.

As stated it will probably either be a too low idle (should be 700~ min when warm) or a lean mix. Check your plugs for colour.

This isnt really a restoration project thread, more general dolly.

Sure it will get moved in due course....

I'm happy to look at this for you if you are anywhere near west london.

Sounds like a discharged battery. How or why needs a bit more diagnosis....

Jonners

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Note from Admin: sadly Jon passed away in February 2018 but his humour and wealth of knowledge will be fondly remembered by all. RIP Jonners.

Thanks, turns out it wasn't the battery. Got it going, then found fuel on top of the float chamber nearest the grill. Engine off quickly, didn't want a fire. The float chamber is loose, and we need to take off to get a better look. More than likely ruining the mixture. Oh well, at least it didn't catch fire.

Lots of threads on this.

and this article....

https://www.dollywiki.co.uk/wiki/SU_Carburetor_Tuning

Jonners

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Note from Admin: sadly Jon passed away in February 2018 but his humour and wealth of knowledge will be fondly remembered by all. RIP Jonners.

Thanks I am going to need all that. Hope that will fix it, well that and replacing the middle section of the exhaust that has a hole in it.