My CEL either flashes, flickers or goes solid on longer journeys, for the last 2 years. I have replaced the NPS, plugs, coil packs, cam sensor, front o2 sensor and had timing checked. The car is used for mostly shorter journeys, where the cel is not a problem.
It does not start 1st turn, and runs lumpy from cold, sometimes shaking at idle,
but pulls and drives well, with a tiny hesitation before boost comes.

I am checking earthing, cleaning maf, and checking for vac leaks and plug gaps, but this is driving me mad, so any suggestions would be most welcome; I`ve read that carbon build up on valves could be an issue, with the short trips, so am looking at injectors next.
There was also a suggestion from a mechanic that the fuel pipe connection onto the rail can perish, and we did have a fuel smell once in cold weather.
85000 miles, stage 1 05 wagon

Thanks, in hope.

 

Have you ever had a basic engine health check, like compression test or cylinder leakage test ?

 

is the car standard ?

 

I had a compression test 2 summers ago, when the light 1st started showing; all was fine. Martyn J read the codes this August, also said the engine was fine.

Just been out, 25 min drive, all fine, B roads; parked up, went for a walk for 45 mins, drove onto main road and accelerated in 2nd, not flooring it, and it clearly stuttered as it hit around 2800rpm, light flashed and came on solid within 10 seconds.
Stig, it`s stage 1, but hasn't ever felt progressively smooth under acceleration, more like it is a bit held back off boost, almost hesitates, and then flings itself forward, if that makes sense ?
I have had it 5 years, since 16 000 miles, always serviced, sports cat, panel filter. I want to sell it, but cannot with this, as I have an order down for a jdm grb hatch.
Thanks for your replies.

 

I would take it to rich at fb tuning.
I'm sure he would know what was wrong.
Maybe needs the map checked.
He's mapped two of my subarus and they've never missed a beat mate.

 

I just had the timing checked last week, after our chat about it, but was disappointed that it was fine; had a tensioner replaced, spent loads, and nothing solved. In fact it has been worse, if anything.
I am going to get another compression and leak down test, and start from there, as most of these "specialists" seem quite happy to throw parts at it without any logical methodology. Paul Finch has said that he has seen similar situations with valve problems, so the tests combined should give a clue, and he knows what he is on about.

 

who did the "stage 1 map" ?

 

Martyn at Enginetuner