ignition problem: Knock sensor?

RiskyBusiness · **Posted:** Mon Mar 15, 2010 7:08 pm

Hello all, hope everyone had a good weekend.

Decided to take a trip to Slough on Saturday to have company called Profusion Customs look at my 85 S2 and give me a quote for a custom exhaust system. I was impressed by the set up and they seemed knowledgeable and so I will be having the new system installed on Thursday.

However (as always), the car didnt seem to be running at 100 %. When accelerating hard, from 4000 to 6000 rpm the performance was much weaker than normal, although sometimes it felt as if full power was briefly returned. I'm guessing that its something timing/mixture related, but it has also been suggested that it might be the knock sensor or hall sensor playing up. Has anybody had similar problems/experiences?

Brett928S2 · **Posted:** Mon Mar 15, 2010 8:40 pm

Hi

Generally speaking, lack of power is not anything fancy like sensors its usually the simple parts failing under load, particularly if on a light throttle things improve....

Soooo...when did you last CHANGE the plugs, dizzy caps, rotor arms and leads ??? Also the fuel filter and air filter ?

I emphasise change not check ??

All the best Brett

RiskyBusiness · **Posted:** Tue Mar 16, 2010 10:22 am

Morning Brett,

Thanks for your advice, as ever. I had the plugs changed at Paul Anderson's in January and I replaced the air filter with a K&N item at xmas. \I asked Paul to service the car at the same time as having the fuel lines repaired and the problem seems to have developed since then. I was hoping to take the car to JDS in Cambridge to have them run the Sharktune on it but i need to get everything 100 percent first. Unfortunately, regular trips to Stroud eat into my limited mileage allowed by my insurance............. The joys of classic car motoring.

JDSPorsche · **Posted:** Fri Mar 19, 2010 10:06 am

Your S2 doesn't have knock sensors.......

Brett928S2 · **Posted:** Fri Mar 19, 2010 6:11 pm

RiskyBusiness wrote:

Morning Brett,

Thanks for your advice, as ever. I had the plugs changed at Paul Anderson's in January and I replaced the air filter with a K&N item at xmas. \I asked Paul to service the car at the same time as having the fuel lines repaired and the problem seems to have developed since then. I was hoping to take the car to JDS in Cambridge to have them run the Sharktune on it but i need to get everything 100 percent first. Unfortunately, regular trips to Stroud eat into my limited mileage allowed by my insurance............. The joys of classic car motoring.

Hi

JDS will find ANY electrical problem, but before that if you do not know WHEN they were last changed . I would CHANGE the dizzy caps and rotor arms.....personally I would never use caps and arms for more than 2 years.....they WILL cause miss-fires or low voltages....and weak spark equals lack of power...

All the best Brett

stratfordshark · **Posted:** Fri Mar 19, 2010 7:13 pm

JDSPorsche wrote:

Your S2 doesn't have knock sensors.......

...or a hall sensor

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ignition problem: Knock sensor?

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