Thread: 3.5 Carby V8 hard to start when hot

Maybe the refiners have switched to "winter" petrol and the increased volatility is causing vapour lock in the current hot weather.

Have you tried dousing the carbs in water then trying? as much as I hate to recommend water near a V8.LOL.

Regards Philip A

Gary,
It does sound like a vapour lock.
Another thing to check, could it be the fuel pump (I'm having issues with my fuel pump at the moment) or maybe a split or leak in the fuel line letting air in?

Thanks guys - with the fuel pump in the tank it is unlikely to be fuel line vapour lock - there is plenty of fuel to the carbies but I am not sure about a vapour lock in the carbies - it has only been about 30 today so outside temp is not a major issue.

Will not even start on areostart.

Just about to go out and check the electrickery and see if there is a spark to the plugs etc.

Garry

if it wont start on areo start then its spark related...

probabley the points arcing just enough or the condensor not playing when its hot.

hi Garry

has it got a stablizing resistor (large ceremic resistor)near the coil if so try shorting it out (may have a high resisttance contacts on starter motor)

or it could be a faulty coil ---when hot may have an internal short

hope this helps

Maurice

Originally Posted by Blknight.aus

if it wont start on areo start then its spark related...

probabley the points arcing just enough or the condensor not playing when its hot.

Decided to check the carby diaphragms so took off the tops of the carbies - they seem OK but I have a spare set so I will put them in. When they were off I squirted aerostart directly into each inlet manifold - still no start so leaning towards ignition.

Checked No 1 plug lead and there is plenty of spark - jumped into my left hand and out my right hand as it earthed on the ignition switch as I was cranking.

So I think a new set of plugs, leads, points, condensor and we will see.

So some questions related to settings noting that it is dual fuel.
1. I will just use the same spec plugs as are in it as they seem to have been working well - what is the best gap for dual fuel? The book says Champion RSL 92Y with a gap of .6mm.

2. Noting that I have dual points - is a different gap required for dual fuel. The book has .35 to .4mm. Any special tricks for dual points??

3. Timing - what is appropriate for dual fuel - for 91 - 93 octane fuel the book says 3 degrees before TDC. As a side any recommendations for when I go to premium unleaded/lpg when E10 comes in to replace standard ULP mid year.

Thanks

Garry

Garry

does it have an electronic module on the distributor?

LPG will handle 20 degrees of advance on a low compression engine and premium about 5-6 over standard

fill it up with premium burn through a tank and refill then with the engine hot and the vehicle loaded up drive it hard till advancing 1 degree or so at a time till it just starts to ping on the premium then back it off 2 degrees.

in winter you can run more advance due to the cooler running of the engine.

you might have a problem with the dual fuel control and its trying to run both fuels at once flooding it out completely. areostart wont help you then.

points gap remains the same across the range of fuels but messing with the plug temp and the gap is worth doing. lpg likes a colder plug and Ethanol fuels like a hotter one.