Discussion
Hi All,
Just wondering if anyone has any ideas what could be the problem, the garage reckons it is the boost solenoid. They had it the other week and cleaned it through, but it hasn't solved the problem.
The symptoms do not show as much when cold. Say you are sat behind a truck at 70 (ish) and you plant your foot down to go past it, at 3000rpm it really coughs and splutters, through to about 3800rpm. This happens in 3rd, 4th and 5th, haven't really noticed it in 2nd, but you probably wouldn't. If you put your foot down nice and gently, it's not too bad, just a slight hesitation.
Other than that the car is fine - starts and runs/idles fine.
Cheers.
Just wondering if anyone has any ideas what could be the problem, the garage reckons it is the boost solenoid. They had it the other week and cleaned it through, but it hasn't solved the problem.
The symptoms do not show as much when cold. Say you are sat behind a truck at 70 (ish) and you plant your foot down to go past it, at 3000rpm it really coughs and splutters, through to about 3800rpm. This happens in 3rd, 4th and 5th, haven't really noticed it in 2nd, but you probably wouldn't. If you put your foot down nice and gently, it's not too bad, just a slight hesitation.
Other than that the car is fine - starts and runs/idles fine.
Cheers.
In very basic terms the spark is jumping to ground, it takes the easiest route. The pressure, fuel mixture, rpm will effect how easy it is for the spark to jump the plug or to the head via a crack in a coilpack or spit in a ht lead or if coil is weak jumping anywhere.
Usually occurs at peak torque.
So depending on which model, year and mods you have (hence my question) 3000-4000rpm
Simon
Usually occurs at peak torque.
So depending on which model, year and mods you have (hence my question) 3000-4000rpm
Simon
Unfortunately there are a million and one reasons why this sort of thing starts to happen. There are also a few things that have the same effect on the car, ie loss of power, hunting, spluttering etc etc especially on the older models now.
I know as I went through most of them....here is a list.
Spark plugs - Pull one and tell us what the code is, check gaps replace - free
Coil packs breaking down? - Are they on the plug on RB5s? Check the tip for cracks, damage or carbon build up.
MAF sensor Spray electric contact cleaner on it (don't touch it)
Boost solenoid spray through (done - its not that)
Detonation / Pinging? - Possible, have you ever tried the Subaru top engine cleaner? Carbon build in boxer cylinder > detonation > boost reduction - I had this on my Classic STI. Octane booster temporarily improved it, engine spray cured it.
Good luck.
I know as I went through most of them....here is a list.
Spark plugs - Pull one and tell us what the code is, check gaps replace - free
Coil packs breaking down? - Are they on the plug on RB5s? Check the tip for cracks, damage or carbon build up.
MAF sensor Spray electric contact cleaner on it (don't touch it)
Boost solenoid spray through (done - its not that)
Detonation / Pinging? - Possible, have you ever tried the Subaru top engine cleaner? Carbon build in boxer cylinder > detonation > boost reduction - I had this on my Classic STI. Octane booster temporarily improved it, engine spray cured it.
Good luck.
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