924Board.org

[tscharke]

Only just started happening. The first start up in the morning on a cold engine there is no problems however once warm, everytime on start up it runs on 3 cylinders for about 10-15 seconds which then it comes good. It feels like it is flooding or something like that.

Is this a common problem with the 2.0 NA 924's? I suspects it has something to due with the fuel injection - my experience is all with webber carbed engines so I don't know where to start

Any suggestions?

I can try to rev the car until in starts running on all four otherwise I can just let is roughly idle until it rectifies its self!

The only different that I have recently made is putting a non-auto venting fuel cap on so I don'k know if that is linked to the issue - maybe something to do with the pressure in the fuel system, forcing fuel into one of the cylinder when sitting idel for a while....wild guess!

any suugestions would be graetly appreciated

I have the car booked in at a specialist Porsche garage charging AUD$150 per hour so it would be nice to have it fixed before thay start looking at it

Cheers
Scott

[larchie]

A leakly injector on that cylinder is a first possibility and the most likely. Check and see that the suspect injector produces the same volume and flow as the others (HanesCh. 3, sec 11). This section linked to the Hanes Manual covers how to troubleshoot for one cylinder not firing properly.

If spark plugs and wires are not replaced as a set and the plugs and wires are not matched, it is possible have variation of cylinder firing. How does the suspect plug look in comparison to the others? Is it properly gapped? Are the suspect plug wire connections properly seated? in the loom and away from a heat sources? wire checked when wiggled for continuity? As the wire or plug heats up, continuity might vary.

There are other factors but these probably might be checked first. If a different fuel cap were to be a factor, it seems all cylinders would be affected not just one.

[tscharke]

thanks mate, I will look at these possibilities when I get home tonight.

Cheers
Scott
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1981 Porsche 924 2.0 NA