HELP!!!! Unknown fault... any ideas???
 

I put my foot to the floor it doesn’t accelerate cleanly , it hesitates and shudders most notable at 4000rpm. Once it gets past that it feels like the turbo isn’t boosting.

This has been going on for months and I have changed the MAF sensor and now on Saturday changed the ignition leads at a dealer after their fault finding exercise. Drove it from Forfar to Aberdeen, 50miles on a duel carriageway, with no problems at all, it accelerating normally and pulled cleanly from various speeds in 5th gear. I even gave it full throttle in 2nd gear going on to the duel carriageway and felt like it should. Got up to Aberdeen a happy man, then stopped at e shopped for about 30mins then jumped in and the faults is back again, not quite as harsh as it was but still hesitating.

I don’t want to keep throwing money at this without knowing what the real problem is. Has anyone had anything like this before? I’m now thinking it could be the coils or a fuelling issue.

Anyone any idea,

Thanks in advance

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Hello
First of all, can you let us know what car you have? mods? etc etc

My first shot in the dark would be........................have you changed the spark plugs as you changed the coils?

Also if you have a standard ecu I'm surprised it doesn't showup a fault code?

Kev

cat collapsed?

I have a UK Impreza Wagon Turbo 2000, X REG, only mod is a K&N pannel air filter.

The plugs got changed when the last service got done (Oct 05). The cars done 94000 miles, if the coils are the originals then would this point to them being at fault?

Cheers

Ignition leads/coilpacks are the same thing depending on what year car you have?
So as you have mentioned you have new leads and plugs, therefore can you just confirm, are you gettting any cel warning light coming up?
Kev.

No warning lights, I have a coil pack that’s got all 4 leads sockets on it. Looks like one solid square black module sitting to the right of centre on the engine.

With the changed leads the hesitation feels smoother if that make any sense.

It's going in for an oil change next month so I'll get the plugs checked for the gap size.

I would just go and get a new pack but it's going to cost me £150 form Subaru, trying to source a second hand one at about £50 but difficult to know if it's the right kind. If it's not the coil then I don't fancy being out of pocket £150 because that half the cost of a new exhaust that I want...

...I wonder if they would do a sale or return and I could try the good part and see if it sorts the problem.


Thanks all for the responses