My '90 S2 has a bit of a misfire if I slam the accelerator to the floor. The car judders for a few seconds, then picks up and off we go. If I accelerate slightly smoother everything is fine and the car accelerates just as rapid as usual. I've also noticed some puffs of black smoke when the juddering is happening.

I've checked the plugs, and they are all sooty black, which makes me think its running too rich. I'ts also using more fuel than usual. It''s gotta be the mixture right?

Does the S2 have a manual adjustment screw or is it off to someone with a plugin diagnostic kit?

Its a long holiday weekend here in the UK and I need to get this sorted before next Wednesday because I'm leaving for Le Mans

Thanks,

Paul

'90 S2 Panther Black
'89 Turbo Baltic Blue
'91 Metro Gti (Brit shopping cart)

 

I am almost positive that there is not a manual adjustment screw.

You did not mention if this problems happens at low RPM’s only or if it happens anywhere in the power band.

My first guess is that it may be the O2 sensor (and it is a guess), but I would also check the condition of the plug wires, the coil, and the distributor cap & rotor.

I think a plug in diagnostic may be in order.

 

Thanks Michael, I don't think there is either.

It happens at all revs and in all gears, but only if you slam your foot to the floor. I first noticed it whilst overtaking at 70mph on our Freeways. I saw a much, much faster car coming up behind, so floored it to get out of his way and move over, but all I got was judder.

In normal (and even spirited driving) you would not notice a thing, you can even floor it slightly gentler and its fine???

I've visually checked the leads and coil and distributor and they do seem fine.

I guess I will just have to wait for the mechanics to open tomorrow and hope they can fit it in before I leave next week.

Paul

 

Hooray for plug in diagnostics

The problem was the engine temp sensor.

It was reading cold no matter what, so the ECU just kept on pumping in fuel until it would get warm.

$20 part and I'm happy once more (so is the car)

Paul