Losing power at higher (!) speeds

Standard & electronic conversions

Losing power at higher (!) speeds

Postby Harlequin1973 » Tue Nov 19, 2019 9:32 am

Hi all - I come to you in the hope that you can help me and my beloved Mildred (Morris 1000) :( . She runs as beautifully as ever at lower speeds (up to about 40mph) but is suddenly really struggling when going faster for more than about 20 seconds and/or uphill: including coming to a halt recently on a dual carriageway! She seems to be burning a little more oil than usual too - but that may be totally unrelated of course (new bottom end in order at some point). Carb dashpot all fine.

I thought at first it was the fuel pump or a dirty air filter but the pump (electrical) seems to be working fine and its not the air filter either. What should I look at next wise ones? All I can think of is replacing the vacuum advance pipe - I don't think it can be the timing as she runs just fine at lower speeds. Or could it be the head gasket is going (again!). Or is it more likely to be a general timing issue?

Thought much appreciated!
Jim
Harlequin1973
New Poster
 
Posts: 2
Joined: Thu Nov 09, 2017 4:12 pm

Great Britain (GB) UK England (.g)

Re: Losing power at higher (!) speeds

Postby Panky » Tue Nov 19, 2019 9:45 am

Hi Jim and welcome :)
Have you done any work on the engine lately? If so I would go over those things first and make sure all is OK, if not it could be fuel starvation. Check out the flexible fuel lines as they could be collapsing internally or possibly a blockage or air leak on the suction to the pump, do you have an in line filter? also check the filter mesh in the pump itself.
Hope this helps
Image
User avatar
Panky
.
 
Posts: 1265
Joined: Sun Mar 22, 2015 6:00 pm
Location: Cheshire

United Kingdom (uk) UK England (.g)

Re: Losing power at higher (!) speeds

Postby Harlequin1973 » Tue Nov 19, 2019 9:51 am

Thanks Panky -
Not done any engine work recently - good advice on the fuel lines: I'll give them the once over. I've not fitted an inline fuel filter - the extra pressure on the pump doesn't seem worth it - but will check the one in the pump.
Jim
Harlequin1973
New Poster
 
Posts: 2
Joined: Thu Nov 09, 2017 4:12 pm

Great Britain (GB) UK England (.g)

Re: Losing power at higher (!) speeds

Postby MM » Wed Nov 20, 2019 3:40 pm

Also check that the fuel filler cap isn't causing a vacuum inside the fuel tank - try undoing it with the engine running after a run; if it makes a 'whoosh' of air as you undo it, you may need to get a filler cap with a small vent hole in.

Other possible causes may be an accumulation of gunge (silt, etc.) inside the carb float bowl and/or jet.
Maurice, Kent.
1970 Trafalgar Blue Traveller

http://retrorides.proboards.com/index.c ... read=37056
User avatar
MM
.
 
Posts: 3745
Joined: Tue Jan 25, 2011 11:15 pm



Return to Ignition, Carburetion & Fuel



Who is online

Users browsing this forum: No registered users and 1 guest