General 2010 Evo 1.48v : Struggling to get over 60mph

[aicwilson]

Looking for guidance to an issue on my sons 2010 1.4 8v Punto Evo with 62k on clock. Vehicle has been sat for around 9 months. Just changed plugs and air filter.... oil had been done just before being laid up. Car drives perfectly around town.. spritely and as would be expected. However get it onto a faster road either flat or up hill and the vehicle is toiling, spluttering / stuttering and running out of puff.

Thought may have fuel starvation from contamination, rust from lay up, but no codes on daig.... idea was to change fuel filter but apparently lifetime filter I am told? Could be clogged injectors...which will now run application through fuel to clean/clear.. but then would I get the drive round town I am getting?

Do have a EML issue currently as a result of a start stop / neutral position sensor re-learning fault....but cannot see this causing limp mode

Any guidance, solutions, thoughts greatly appreciated.

TIA

 

[eeeno]

Which fault codes does the car have?

If the issue wasn't there 9 months ago, it'd have to be fuel related. Fuel has accumulated lots of moisture and in Britain there's plenty of rain all the time. The issue will most likely resolve itself when you refuel the car. You could drive it in the slower roads to burn off that old fuel. The car most likely has just a small filter in the fuel pump housing which can't be replaced.

My other guess would be that the timing belt needs to be changed. When was it last changed? Or it was changed without carrying out proper self-learning procedure or the crankshaft pulley is out of alignment.

If the car just drove beautifully before, there's no reason to start changing parts before seeing if it actually is a fuel related problem.

 

[aicwilson]

@eeeno thanks. fault code is P1305-62 Neutral signal learn.

Have replaced fuel through already tbh. Not used injector cleaner additive though so could be issue but as said doubt would allow it to run nicely sub 50mph.

Note on timing belt ....worth checking

 

[chris3234]

Which fault codes does the car have?

If the issue wasn't there 9 months ago, it'd have to be fuel related. Fuel has accumulated lots of moisture and in Britain there's plenty of rain all the time. The issue will most likely resolve itself when you refuel the car. You could drive it in the slower roads to burn off that old fuel. The car most likely has just a small filter in the fuel pump housing which can't be replaced.

My other guess would be that the timing belt needs to be changed. When was it last changed? Or it was changed without carrying out proper self-learning procedure or the crankshaft pulley is out of alignment.

If the car just drove beautifully before, there's no reason to start changing parts before seeing if it actually is a fuel related problem.

Fuel issues are quite rare these especially with modern plastic tanks so minimal condensation issues

 

[eeeno]

Still very possible for the condensation to occur if the tank was never full.

Another guess, check the pcv breather hoses. If you have an obd fault code reader, you could check engine coolant temperature sensor reading when cold and warmed up. Also check that the obd readiness monitors have "passed" for catalyst and lambda. However EML light would illuminate if there was any fault.

You could try some kind of fuel additive. However they're never recommended.

 

[chris3234]

Still very possible for the condensation to occur if the tank was never full.

Another guess, check the pcv breather hoses. If you have an obd fault code reader, you could check engine coolant temperature sensor reading when cold and warmed up. Also check that the obd readiness monitors have "passed" for catalyst and lambda. However EML light would illuminate if there was any fault.

You could try some kind of fuel additive. However they're never recommended.

Not really pretty uncommon now don't recall any posts of issues on here last few yearsmore an issue on large statics tanks then on cars