[Mgs] Performace queery

[The Roxter]

Richard Ewald wrote:
> A problem such as this can be caused by several things.  Paul 
> mentioned misfire and high voltage break down.  This is a strong 
> possibility.  Your B probably needs about 10-12K volts to fire the 
> plug at idle.  Open the throttle and it might take up to 20K volts.  
> If your car's plug wires start firing to ground at 15K volts it will 
> run fine at idle, and low throttle openings.  A large throttle opening 
> will cause the engine to misfire and no acceleration.
> A low output from the coil could also cause this.  If there is not 
> enough voltage going into the coil due to poor connections this could 
> show up.  It could be a bad coil, but honestly, these are real rare.  
> Coils almost never go bad.
> These are just some of the reasons that back in the day tune up shops 
> had O-scopes in them.  About 30 seconds on a scope and I could nail 
> the problem.
> I very seriously doubt it is a vacuum leak.  As a percentage of total 
> air going into the engine a vacuum leak is greatest at idle.  A vacuum 
> leak having an effect at 3500 RPM would require a huge leak, and I 
> doubt the engine would idle.
> Stuck carb pistons could cause such an issue, but I would look at the 
> electrical stuff first.
Another possibility would be a clogged fuel filter or weak fuel pump.

-The Roxter
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