Loss of power on boxster in second gear?

[madasafrog666]

A couple of times recently I have lost power while in second gear, pulled over to the side of the road the engine does not cut out.
Put back in first again and everything is fine in only a couple of seconds.
Then drive away as normal. Any ideas as to what this might be??
I would not like this to happen at high speeds on a motorway etc.

Thanks.

[frozen-in-wiltshire]

just second gear? or is that the only place you have noticed? sounds more like engine than gearbox - so just in second sounds odd. off to dealer and plug in to diagnostics asap I would think - if something wonky then that should show quickly - possibly coils, sparks, injectors or fuel supply as a thought - but would check diagnostics asap to see - unusual.

[madasafrog666]

I think its just that it has happened twice in a week and while I was in a 30 mile limit.
Its definitely engine related not gearbox.

[madasafrog666]

Full diagnostic check today and no faults found.
Even the garage couldn't think what it might be? done about 30 miles today and no problems.


Any ideas....anyone on here had a similar problem

[jakesmith]

Which model, engine, gearbox?
Can you give a bit more specific detail about what happened so the power dropped off - did you put the clutch down to prevent stall & pull over or what?

I'm wondering if it is a MAF issue that's causing air flow to drop or something

[Rockster]

madasafrog666 said:

Full diagnostic check today and no faults found.
Even the garage couldn't think what it might be? done about 30 miles today and no problems.


Any ideas....anyone on here had a similar problem

If no CEL then no fault the engine controller can recognize. Now it might be possible there is a Porsche proprietary (non OBD2) error code stored but the shop would need access to a proper Porsche diagnostic computer and know how to use it.

A cut out in power under hard acceleration suggests a fuel supply problem. Since the behavior hasn't reappeared what changed? Did you perhaps fill up the gas tank?

What can happen is a fuel line in the tank develops a crack/split or a fitting leaks. Under hard acceleration and with just the right level of gas in the tank the g-force and fuel sloshing can cause the line to move and the split to open up or the fitting to leak and the fuel pump is unable to deliver fuel at the required pressure. The engine controller causes the injectors to remain open a certain length of time with the assumption the fuel pressure will be within pretty narrow range thus ensuring a consistent delivery of fuel per injector pulse. If the fuel pressure drops insufficient fuel gets injected and the engine shows its displeasure by faltering. As soon as the high g-force subsides the internal fuel leak "heals" and the engine is back to normal.

[996Targa]

Have you tried changing the fuel pump relay? Failure can cause loss of power and shut down and in my experience can be hard to trace. For about £14 from an OPC it is worth trying or carrying as a spare.

[Bibbs]

Guy on FB had similar, was a brake switch near the pedal iirc. It'd kill power when giving an issue. Was a cheap fix.

Just had a look "brake pressure switch" and 15 quid.

(This was on a 987 manual)

Edited by Bibbs on Monday 8th October 10:47