Loss of power

Discuss mechanical problems here.
Forum rules
By using this site, you agree to our rules. Please see: Terms of Use
Post Reply
BorthMark
Newbie
Posts: 5
Joined: Mon Jul 25, 2005 6:28 pm
MMOC Member: No

Loss of power

Post by BorthMark »

:cry: Can anybody help me, I'm at a loss. My minor came out of retirement at the begining of the year was ticking over fine but couldn't keep power up. My first thought was fuel startvation but that was not it. I tried everything, gave up and gave it to to a garage. They replaced the fuel pump & the coil and she ran fine for a month or so.

On returning from the National Rally the power went again only a few miles from home. Again I've checked the pump and although is only sparking on one side seems to be feeding fuel. I have re-set the carbs again (thank you Mr RAC man for messing that one up) but still no luck. Any ideas?
johnm
Minor Fan
Posts: 108
Joined: Wed Nov 03, 2004 8:42 pm
MMOC Member: No

Post by johnm »

Assuming the pump is OK and you can check for fuel flow by disconnecting the fuel pipe from the carb and getting it to pump into a petrol can. Should be a gush not a trickle and the pump should be ticking frantically. Careful, ideally use two people, one to turn the ignition on and off fairly quickly and one to hold the pipe and can.

The other possibility is blocked fuel tank vent. I have the car occasionally just not start or hesitate and lose power and the solution is to remove the locking petrol cap. It's very intermittent on mine.
Kevin
Moderator
Moderator
Posts: 7592
Joined: Thu Feb 14, 2002 12:00 am
Location: Watford, Hertfordshire.
MMOC Member: No

Post by Kevin »

Is the replaced fuel pump a proper SU one as the aftermarket Hardi ones are renowned for problems, and has the right type of coil been fitted, I would also have a look at the carb needle to make sure its clean as your symptons are the same as I had earlier in the year and the needle had some tiny bits of dirt on it which once removed solved the problem.
Cheers

Kevin
Lovejoy 1968 Smoke Grey Traveller (gone to a new home after13 years)

Herts Branch Member
Moderator MMOC 44706
BorthMark
Newbie
Posts: 5
Joined: Mon Jul 25, 2005 6:28 pm
MMOC Member: No

Loss of Power

Post by BorthMark »

John M - Excellent and so simple, hadn't thought of that.

Kevin - Coil looks to be correct and you are right the mechanic replaced the trusty old SU pump with an aftermarket copy. Carb needle is good, have cleaned it several times to no avail.

Hope to re-attack on Friday so will try all your suggestions. Cheers
Willie
Minor Legend
Posts: 3204
Joined: Tue Feb 12, 2002 12:00 am
Location: S E London
MMOC Member: No

loss

Post by Willie »

If your problem is caused by fuel starvation(faulty petrol pump)
you should remove one of the plugs as soon as the fault condition
returns and observe the colour of the electrodes. If the mixture is
too weak then they will be white. This condition would often cause
spitting back in the carb.
Willie
[img]http://i39.photobucket.com/albums/e197/wuzerk/mo9.jpg[/img]
bmcecosse
Minor Maniac
Posts: 46561
Joined: Wed Feb 16, 2005 11:24 pm
Location: ML9
MMOC Member: No

RE: loss

Post by bmcecosse »

But fuel starvation should only affect full bore running - the pump should be able to deliver 1 pint per minute - which is more than enough. You say 'carbs' - has it more than one ?
ImageImage
Image
BorthMark
Newbie
Posts: 5
Joined: Mon Jul 25, 2005 6:28 pm
MMOC Member: No

RE: loss

Post by BorthMark »

Thanks for all your suggestions. Turned out to be a leaky manifold gasket!!! All back , up & running again!!! :D
bmcecosse
Minor Maniac
Posts: 46561
Joined: Wed Feb 16, 2005 11:24 pm
Location: ML9
MMOC Member: No

RE: loss

Post by bmcecosse »

Don't understand how manifold gasket can leak - unless the securing nuts had come loose ?
ImageImage
Image
Post Reply