mk2 Golf 1300 transistorized ignition system - jumpy engine

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Sat 14 May 2011 18:15
mk2 Golf 1300 transistorized ignition system - jumpy engine - golf-driver

Whilst driving when I ease off on the accerlator pedal the engine becomes somewhat jumpy & hestitent. When I'm accerlating the engine is not jumpy and is normal, this is also the case when the foot is completly off the accerlator pedal.

I reckon the fault is with the vacuum advance unit on the distributor, I removed the pipe and sucked on the vacuum unit, I was continously drawing air.

If I replace the vacuum unit will this stop the jumpy engine? I wanted to make sure as I've read that it's very tricky to replace the vacuum unit.

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Sat 14 May 2011 19:14
mk2 Golf 1300 transistorized ignition system - jumpy engine - dadbif
Is the vacuum advance unit on the sideof the distributor? If so, does the arm or did coming out of it move when you suck on the pipe?
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Sat 14 May 2011 22:12
mk2 Golf 1300 transistorized ignition system - jumpy engine - golf-driver

The vacuum advance unit is on the side of the distributor.

As the vacuum unit is connected to the distributor I'm not sure if the arm moved. I was continously sucking air, is not the diaphram damaged/erroded as it's letting through air.

This distributor is a used unit that replaced the original distributor. I removed the vacuum unit from the original distributor and did the same test, here the arm did not move.

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Sun 15 May 2011 15:26
mk2 Golf 1300 transistorized ignition system - jumpy engine - Peter D

It should not be letting air through. The arm will move if sucked hard enough on a working unit. Regards Peter

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Sun 22 May 2011 13:40
mk2 Golf 1300 transistorized ignition system - jumpy engine - golf-driver

The vacuum unit does let air through.

If I fitted a new vacuum unit will there be any problems fitting the lever as it looks fiddly.

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