Had a 16v recently that had ruff idle and didn't like initial throttle opening, all else was ok. Took the new pattern distributor off (ebay) OEM distributor trigger wheels 15.5mm Ebay one 13mm and one was 14.5mm Also the ebay one had a different set point in relation to the rotor arm and trigger window. Also the hall sensor was a copy of the OEM type See pictures for attached. Put the OEM one back on with new seal and sensor and all is well and drives great First picture is ebay top/OEM bottom Second picture is ebay Third picture is OEM
Interesting stuff... are you saying the non-standard dizzy trigger wheel had some gaps of 13mm and some of 14.5mm or do you have 2 x non-standard dizzies one of which has 13mm and the other 14.5 mm gaps? The diameter of the non-standard trigger wheel... does it match that of the standard one? I'm thinking if the non-standard wheel isn't the same then it might account for the different gaps though 1.5 mm seems a lot)... in theory one'd be turning faster than the other and therefore need to be open for a longer / shorter duration to obtain the same open periods ? Hard to gauge from the angle of your images but is the air gap between the visible portion of the Hall sender and the wall of the trigger wheel (that has the gaps in) smaller on the non-standard dizzy... apparently that gap can have an impact on the good running of the engine. You having an aftermarket dizzy and a standard one is a good oportunity to compare differences. Do you have the VW/Bosch and aftermarket dizzy numbers, curious to see what the non-standard one is claiming to fit?
yeah we have seen similar with other 16v owners having poor performance with pattern dizzy vs the old one they just took off. all we could theorise at the time was incorrect trigger wheel so good to see a confirmation
Yes the stock OEM was all 15.5mm that was the same on two other OEM ones ebay one was three at 13mm and one at 14.5mm with a different break point in relation to the rotor arm.
Wrong gap size in itself is concerning, but different sized gaps is another level... QC must be non existent.
And this is why spurious parts are to be avoided like the plague whenever possible - absolutely staggering
