[Toomanycars]

Our gti engine as you look at it from the inlet manifold side has some sort of vacuum sensor thing on the top LHS of the manifolt and it has one hose going to a vacuum plug and the other hose just comes out of this sensor and hangs in the air between the middle of the 4 inlet manifold pipes... Should that end be connector or does the pipe just hang there..

[losfer]

Hose goes to the purge canister. Usually on gti not far from manifold. Furter away on gti in sierra..

[Toomanycars]

Ahhh that would explain why the purge canister hose is just hanging down to the transmission....LOL.. Cheers Mate...

[Toomanycars]

We connected the canister hose to the Sensor and straight away the hesitation from idle stopped...Obviously that "sensor" was happy to see fuel vapors instead of just air being sucked through it....It's gone to a friends tonight to check the timing after it had it's new 90 degree dizzy cap and rotor fitted..