hi i've just brought my first zx tt. ran like a dream at first but now seems to be over fueling. its fine when i first start it up then when it gets warmed up it sounds like it splutters and miss fires every time i put my foot down and the warning light for the cats comes on. it back fires and there is a strong smell of fuel but no leaks. what could be the problem and could i sort it myself, or is it going to be expensive? please help cheers

One of your cylinders is not firing.

Could be a connector to a coil pack but more than likely its your ptu. Try cleaning all the connectors as they get a build up of green stuff.

 

Thanks

hi i've just brought my first zx tt. ran like a dream at first but now seems to be over fueling. its fine when i first start it up then when it gets warmed up it sounds like it splutters and miss fires every time i put my foot down and the warning light for the cats comes on. it back fires and there is a strong smell of fuel but no leaks. what could be the problem and could i sort it myself, or is it going to be expensive? please help cheers

 

Not an expert by any means mate but overfuelling is often caused by one of the measuring devices not working properly, sounds like mayb the o2 sensors or AFM are not working properly. AFM is easy to get to, try it first un clip it and see if the car runs better although your revs will be limited, if it is the o2 sensors, not that difficult to do just awkward as its on the exhaust manifolds and hard to get out after 15 odd years of high temps. Have you been in any really bad weather recently as the AFM doesn't like this much?

 

Let us know how you get on

 

Cheers

 

Ste

wow what a quick reply! will check tomorrow and let you know. cheers

With mine I had the same. If it is just when the engine heats up then its the PTU. If its when the weather is bad then its the AFM. Mine both went at the same time and trying to drive 200miles getting high on fuel vapour and the CAT warning light on constantly was rather stressful, especially having to stop at every services to cool the PTU down. It sounds like its your PTU. If it starts doing it, turn the engine off and get a wet tea towel and hold iton to it to cool it down. If the car starts running fine again then its definately your PTU.

Check PTU and engine temp sensor connectors ;)

Check PTU and engine temp sensor connectors ;)

 

Listen to this man he is the expert :bow:

it was the PTU! put a new one on and it runs perfect. thanks for the help, saved me loads of £££££££££££££!

glad its sorted mate