Stage Rally Car Fault After Hot Stage

[2ltrrabbit 0]

Hi all, I got a problem which only happens during an event if its hot.

After a stage or two with the car and weather hot, the car won't idle without help and struggles to rev. Take plugs out at service and there black.

Flat out its not noticeable.

I've got twin 45s

I've replace coil and plugs on the ignition and its still there?

Could it be starved of oxygen ?

Cheers

Edited July 25, 2013 by 2ltrrabbit

[welshpug 1,626]

Get the carbs serviced and setup properly, black plugs is running far too rich.

 

Guess you havent a choke cable fitted?

[2ltrrabbit 0]

With the carbs I've already stripped, cleaned and rebalanced. Running fine in all other conditions only happens after a hot event. Nope no choke cable!!

[DamirGTI 327]

Id try an known good ignition amp. (old , Bosch blue amp is the best one ..) along with fresh layer of the heat sink paste .

 

 

Ingition components are sensitive on heat and vibrations .. thus i guess it's something ignition related .

 

D

Edited July 28, 2013 by DamirGTI

[2ltrrabbit 0]

Cheers, Worth a go! Trouble I have is replicating the conditions to make it happen prior to swapping for a new one.

[adman 5]

personally i would listen to WP. to me it sounds like its running far to rich and you won't fix that just by cleaning and balancing the carbs. if it was ign related it would be worse under load not at idle.

[2ltrrabbit 0]

Thats why i cant understand the problem. a revving engine doesn't give the coil alot of time to energise between sparks. I understand what he had said, however on a rally in normal weather it runs faultless and plugs look perfect. It's only in very high ambient temps. Again the car was set up on rolling roads not to long ago. Webers are fixed jets so nothing other than throttle and pump jets mechanisms move. I'm going to fit a bosch if not already on i.t may try and gets some fresh air aimed at carbs or fit a filter box with direct vent to atmosphere.