Hot Running at low revs

[jmgtaylor]

straing thing happended today. Took the car out for a run for some 30 miles top down - had to be done, but at a couple of junctions on the way she was very hesitant at low revs to the point of stalling and dipping the clutch and reving seemed to get her singing again then ok again and no problems until the next junction and no problems at high engine speed - only low speed.

Finally, pulled up at home, went to reverse back in the drive and she cut out and would not start again. Had to push back onto drive - emabarrasing.

Anyway, lifted bonnet, nothing untoward apart from smalll water leak from under manifold somewhere. Plenty fuel in filter bowl, no fuel leaks, had a spark. Left it for 5 minutes and she started first time - really peculiar.

Fuel vapourisation was my first thought but the under bonnet temp was low enough when its only 4 DegC outside. If that was the case it would be undriveable in 30 DegC heat. Note car is a twin stromberg ex USA import though nothing untoward with these as essentially the same carb as on my Stag which run at very hot under bonnet temp.

Any thoughts?
kind regards
Mark

[DaveK]

Mark,

Check the leads and dizzy they don't last forever in fact if you haven't changed them might be a good place to to start looking.
Also it could be the coil breaking down.
Change one item at a time and see how it goes otherwise you'll spend money for nothing and never know the cause.

Please report back as the diagnosis could help others.

Dave

[PoB]

Hi

Good advice from Dave, also check water leak perhaps on to Distributor causing low engine rev problem, high speed may blow water back away from leads etc

Regards
600

[chris.g]

Be careful of repro distributor caps. The one I bought caused no end of problems the rotor arm was hitting one of the contacts. Causing the rotor arm to over heat and breakdown

[DaveK]

Chris,

I bought one from a very well known supplier and had problems after a short while. I then bought one from Holden and its held up very well.
www.holden.co.uk I also bought my rotor arm from there which seems good quality and has also lasted well.

Dave

[chris.g]

I've gone back to the old one. With a new old stock as a spare. The rotor arm came from Ken Jenkins. 80 miles so far with out a problem. Now waiting warmer weather.

[jmgtaylor]

thanks to all who posted, but resolved - I think.

Very slight water leak from the stat housing onto the dissy cap which was being drawn up ino the plug lead rubber caps by capilliary action. Never actually saw it leak, but the colour of the "water" was teh same colour as the antifreeze and does expain my slight coolant loss once hot.

Also slight $h!t (actually more like tarnish / oxidation) on the rotor arm did not help, cleaned that and that helped improve.

So thanks to all, and theres the tip, just because you have check teh cap once does not mean it has not got wet again even on a dry day!.

[DaveK]

I bought some spray on lead sealer from Halfords which seems to work quite well.

Dave