12 replies to this topic

[booton]

ok after being on the track in castle comb on the weekend. car drove lush on the track.

after the car cooled down, there was a loss of power. i originally thought it was the spark plug.
the car has a lack of power, idles well. changed the carb to another i have car ran better with slight more power but still not there. couldn't drive it. [But did not have change to tune it stop on and the Carb has be sat in the garage for a while nearly a year. ( can not guarantee the carb.)]

ok new plugs fitted.
vgood spark on all 4.
compression 150, 150, 155, 150.
no loss of water,
no loss of oil.
no smoke.
all valves adjusted as they should be. (did not need changing, but all checked.)
dizzy timing not changed (all marked up.)
I do have a veneer pulley could that have slipped?
Carb does sound like its sucking air more than it used to. on both carbs.


But I think its the carb. could the carb just break down after cooling down on the track. originial carb was rebuilt start of the year and modified to vizs guide.

You options please. thanks

Edited by booton, 01 October 2012 - 06:29 PM.

[bmcecosse]

Assuming the carb piston rise and falls ok - and you have now tried another car - I would be looking at the dizzy. Any chance the HT leads got muddled up?? 1342 anticlock around the dizzy.

[booton]

both rise and fall.

leads not mixed up.

u think the electronic module playing up or the internal spring seizing, did happen before.

[booton]

so far far general opion is carb or dizzy.

anyone think it could be a bigger issue.
rings bad valve. (but compression all good.)
Adjustable timing slipped, ( but was all tight when fitted.)
???

[jaydee]

Define loss of power.
Because the electronic module cause it to bog down and missfire under load when its gone. And all sort of rev counter buggery.
An air leak leaning off mixture can cause the power loss. Theres a possibility that gaskets were burnt and now slightly leak.
Its unlikely but it could also be the vernier.
Compression is a bit low, was it with no oil in the bores?

[bmcecosse]

Stick in a spare points dizzy and see how it runs...... If you think the cam timing is wrong - do an 'equal lift at TDC' check.

[booton]

thanks bmcecosse.
test with no oil down the bores. justed turned over for 10 seconds.
loss of power.
well under load no power will not pull up my hill. revs up fine, but as soon as you drive it will not pull really bogged down.
when i was driving it back from castle comb hour and a half under 3000rpm would bog down and not pull. would have to change down.
over 3000 car would pull but not with the same power.
will check gaskets tomz.
i do have an eletronic ign New in the box so won't hurt to change it.

Edited by booton, 01 October 2012 - 08:22 PM.

[jaydee]

If pulls over 3k rpm could be timing gone wrong (maybe the dizzy moved about, it just happened to me today ) or the gasket thing.
How do the plugs look like?

[richw911]

Sounds like the Ignition module mine had similar symptoms when it was faulty

[booton]

the dizzy was all marked up and has not moved.
again spark plugs are new and look as they should no oil. not over heating not over fueling.
will check gaskets tonight and change the ign module.
prob been in the car now three years,

[booton]

after stripping everything down. turn out there was two problems.
one a bad earth lead in the dizzy and the timing some how had jumped but not on the dizzy.

i had to replace cable in dizzy and advance the timing by 7degrees.

very strange how the timing had changed. and the dizzy not moved. ( know this for sure as its all marked up.)

only thing i can think of it the veneer timing moved when running over 6500 rpm.
or something is breaking slowly and slowing the spark down thus adjusting the timing.

[booton]

should i be concerned that i had to alter the dizzy timing.

[jaydee]

Its the funny of magnetic ignition units..i'd try different spark plug gaps
Had similar issues with poor quality fuel, required different mixture/timing settings