Intermittent misfire/power loss

[Dan K]

Can anyone help I'm loosing it now. Leon Cupra

Basically under high acceleration high revs the car seems to misfire / loose power then immediately comes back after letting off. Sometimes harsh like there's nothing there and sometimes like a mild misfire.

I've changed coil packs and plugs. Found s split pipe fixed that. Just put a genuine dv valve back on.

I have noticed that on colder weather the temp gauge can drop then rise again more so with heaters on. But normal round town gauge doesn't really move unless heaters are on then it drops and comes back up.

Any help as I'm loosing it now. Scanned on a Aurel computer no codes.

 

[mty12345]

Hi mate, first off the temp thing is your thermostat that needs changing. Classic symptoms there.

As for the misfire, if the coil and plugs are ok and it only happens at high revs/load, then i'd guess that maybe it's not getting enough fuel for some reason.... Could be a weak pump, partially blocked injector or something as simple as a really clogged fuel filter. It needs scanning with VCDS really, as that often shows codes that a generic OBD2 reader won't and without a code or fuel trim info then it really is a best guess.

If no codes showing on VCDS then use it to do some logs of the fueling and boost, groups 002,031 and 115

 

[Dan K]

Thanks for the reply. It didn't seem to do it today after putting a genuine dv valve on but it's only been a day. Fuel filter was probably done about 1.5 to 2 years ago so a possibility. I've got Cupra r injectors how do I clean them if blocked and how do I find out if there blocked.

It's just trying to get to someone with vcds and also without having to keep shelling out.