Random loss of power

[beagle]

My 1992 TL has developed a bad habit.

When crusing at 60mph (top speed) on some journeys the engine will loose power at the car will only go 40 ish (changing down helps) then after a while e.g 20 seconds it picks up again and is fine.

My thoughts are possibly dirt in the carb or water in the fuel or perhaps an ignition component packing up (leads are new).

I'm about to start systematically checking everything but was wondering if anyone knows of a likely soultion to this problem common to R4s?

Many thanks

Tim

 

[malcolm]

Do you have a hose from the air filter to the exhaust manifold? And do you get most of the power back if you pull the choke out a little?

Sounds like the main jet getting a bit blocked, and given the wintery conditions I'd not be surprised if it was caused by carburettor icing.

Though if 60mph is your top speed there might be some other fault - late TLs should be good for 75.

 

[Steve Hennessey]

It would worry me that the car only does 60 flat out!! There's nothing you have said that make this a problem peculiar to R4's. Just wondered if it's to do with the cold weather and the carb may be icing up. Have you pointed your air intake pipe towards the exhaust front pipe? Otherwise check all the normal things.

 

[Steve Hennessey]

Amazing Malcolm - we were typing our almost identical replies at the same time!!! I think it's time for me to retire!!

 

[beagle]

Thanks for quick reply. Yes the winter hose thing is in place. I'll try the choke thing next time it happens. I think I'll strip the carb this weekend, I like taking things apart. I'm no expert by any means but I think my engine is on its way out (89000 miles) as there is often a bit of white smoke (not just after start up). Could this explain low top speed?

 

[malcolm]

Amazing Malcolm - we were typing our almost identical replies at the same time!!!

We're good.

I'd start at a good service - points, plugs, condensor, and fuel filter. If pulling the choke out it could be a blocked main jet, but they don't tend to clear themselves after a bit. Maybe blocked fuel filter could explain it.

What's your fuel economy like?

 

[beagle]

I'm used to old landrovers of the fuel economy is great. I recon about 35-40mpg. I'll buy the parts you mention over the weekend. Will a normal motor factor have them or will I need a specialist?

Thanks again for your sppedy help; much quicker than the AA.

 

[woody]

Classic Carb icing Symptoms me thinks. Most prone at near full throttle operation for long periods of steady speed motoring. The solutions already detailed apply.

 

[angel]

I would bet a clogged fuel filter or clogged pick-up gauze in the tank-have you checked these? Maybe fuel pump not delivering enough petrol?

P.S. The typical carburettor icing problems occur on initial throttle opening (frozen prograssion orifices, not on full throttle.

 

[malcolm]

I've only had icing on full throttle, though that's probably down to my driving style.

Does sound more like fuel filters though. Is there another one on the inlet to these carbs? - the fuel pipe unscrewing from the carb or a brass plug beside the fuel inlet pipe. Well worth cleaning that out too.

 

[beagle]

Thanks a lot for the advice everyone, i've a lot to check this weekend. I'll let you know how it goes. I'm sure I'll be back soon!