948Herald

Hi, so after draining water from the radiator, topping up with antifreeze and refitting radiator hose, I’ve noticed the hose dripping slightly when the car is running and small amounts of steam at times.

Is this to be expected? I’ve played around with the hose to get it as tight as possible but nothing seems to prevent it leaking slightly.

Looking forward to hearing your thoughts, thanks in advance.

- Zee

On 21/07/2022 at 07:44, yorkshire_spam said:

A diagnostic could be the colour of the plugs - if they are very light (indicating a weak mixture) that could point the way. A lean/weak engine will run hot. 

Will check this, cheers!

On 21/07/2022 at 18:03, Nick Jones said:

Sounds like your main problem is fuel vaporisation.  The rough running straight after hot start is the fuel boiling in the carb and loss of power on the move that can be  relieved with the choke is probably a combination of that and the fuel pump loosing efficiency because vaporisation is occurring in its inlet valve.  The latter has the potential to bring you to a complete halt.  Pouring cool water over the pump is the quickest fix for that.

 

As already suggested, a full service, including coolant flush, timing check and renewal of any fuel filters (highly recommended if none fitted) should help.  Modern fuel does have a higher vapour pressure though so you may need to go to an electric pump and re-routing fuel lines to completely eliminate it.  Eeven then the carb vaporising may persist.  Can't remember whether the Herald 948 & 1200s had (or were supposed to have) insulating spacers between carb and manifold?  That might help a bit.

Nick

Thanks Nick, having looked into it the problem points more to fuel vaporisation as you’ve mentioned. Not sure if it makes a difference, but I notice the car struggles to start the first time when its been sat in this heat for a while but after getting started and getting warmed up it appears to behave fine.

Does that still sound like fuel vaporisation to you or does it point to something else?

Will do a full service as mentioned, may look into a fuel filter as the car doesn’t have one fitted.

Appreciate the help so far!

On 21/07/2022 at 19:56, glang said:

One thing thats been suggested in the past is to remove, at least temporarily, the rubber seal between bonnet and bulkhead with the idea of increasing airflow in the engine bay. Its an easy thing to do and if theres an improvement points to the temperature being the problem....

Will give this a go, cheers!

On 21/07/2022 at 18:54, Wendy Dawes said:

This is the type of carburettor spacer on mine available on eBay 

Thanks Wendy, I will purchase one of these as I’ve seen a simillar one on eBay. Think it might help with the fuel vaporisation issue as a heat shield doesn’t seem to be available for the 948.

Thanks for the reply! Yeah I noticed a slightly ‘dirtier’ petrol smell than usual. Looks like the problem might be fuel vaporisation as mentioned below so will be having a play with some solutions.

On 21/07/2022 at 06:22, Piran2 said:

The water sounds ok, not saying that flushing and putting in new stuff isn't a good idea but it sounds unlikely to be your problem.

When starting the car or when it's running rough do you get a petrol smell from the exhaust?

I think you are looking at either fuel or timing for your problems

Hi, hope someone is able to help me with an issue I’ve been experiencing in my recently acquired Herald 948.

On the drive back from a recent long journey, after the car was sat in the heat most of the day, it struggled to start. After taking a few turns to start, it was idling very rough and would cut out after pressing the throttle which I usually play with to warm the engine up. Eventually it started idling somewhat fine and I was good to go.

On the journey back, I realised the car was struggling for power and ended up having to use the choke to make up for the sudden loss of power for some of the journey to prevent holding up traffic. 

Sidenote - I also noticed when stopping to fuel on the way back that the water in the radiator was boiling over after opening the cap (very carefully) and seeing the state of the water.

Anyway, since the journey back, the car still struggles to start and I have the same issue where the car idles very rough when started after being sat and stalls frequently after revving the throttle. Eventually after stalling enough times the problem seems to disappear and the car drives fine.

I’m planning to drain the radiator coolant this weekend and fill with suitable antifreeze to prevent boiling issue, but something tells me this will not solve the problem.

Any thoughts, ideas and recommendations would be much appreciated! I’m at a loss as I’m new to Triumph Herald ownership and after some googling don’t seem to see the issue on any other forums.

Thanks in advance,

Zee