Hesitating at full throttle ?

[Thrumbleux]

I wonder if it isn't a crank position sensor on the way out - but the usual symptom from them is complete engine cut out when warm when the engine has to idle (though I've heard the earliest detectable sign is occasional misfire while driving). and easy re-start once cooled.

[marcjero]

Removing the cap didn't solve the problem.

[Thrumbleux]

Yes that an idea I had. Increasing vacuum would make the pump working harder and harder. I will have a drive with the fuel cap removed.

To be honest I don't know how to check that now that tank venting is so complicated with purging kit. Maybe removing the cap will work. Or, when it plays up again, pull over and remove the cap and listen for any inrush of air?
If not that, I'd suspect an electrical/electronic component fading with heat.
Given you can induce the misfire at standstill, might be worth doing it at night with the engine cover off and looking for stray sparks from the coils to the plugs.

[marcjero]

Yes that an idea I had. Increasing vacuum would make the pump working harder and harder. I will have a drive with the fuel cap removed.

[Thrumbleux]

As a general rule, misfires under load are ignition related, general misfires are fuel related.

Check your tank venting system in case of blockage creating vacuum in fuel tank.

[marcjero]

Hi, the reluctor rings look good and I can get the misfire effect when parked as well. If I open full throttle when parked, engine hits max rpm then slow down to about 4000 rpm with misfires. It looks like something is missing after 1-2 seconds. Maybe fuel ?

[137699]

Check your rear reluctor rings.
Also, get yourself logged onto www.theroadster.net where you will find there are a lot more roadster owners than there are on here.

[marcjero]

Hi Mr T,

fuel filter was changed few thousands miles ago. Moreover problem happens after driving about 10-20 miles.

[Mr T]

Hi & welcome.
Could it be blocked fuel filter that is restricting the fuel flow? https://www.evilution.co.uk/index.ph...vicing&mod=977
Just a guess.

[marcjero]

Hello guys

I just bought a 2003 60kw roadster but I have an issue with it. When warm, the engine stops accelerating at full throttle. I can hear slight misfiring from the exhaust when this happens. If I release the throttle then it can rev up again. I changed map and air temp sensors and o2 sensors (this one was faulty). Turbocharger needed rebuild so I replaced the CHRA. Wastegate is ok. Boost is stable (rock solid 1 bar). I'm sure it's not going to safe mode. There is no error code from ECU.

I wonder what I could check now. I wonder if a faulty fuel system (pump or injectors) could not be the culprit. Spark plugs are new. I changed the fuel pressure regulator as well.
Using Torque I noticed that STFT is increasing to about 10-20% when accelerating. from my opinion it looks like the engine is missing fuel and the ECU tries to compensate with trim. But maybe this is a normal ECU behaviour I don't know. Is it possible that the fuel pump flow decreases when warm ?

Thanks for sharing.
Jerome