Impreza 1800 , 1993 , awd , auto , 100.000 miles.

 

The car is using much more gasoline lately as before , at least 50% more as still 3 months ago.

 

Filters , plugs , spark plug cables ,O2 sensor , all new (oem)

 

Put some cleaning stuff for injectors into the fuel rail for 15 minutes , no improvement.

 

The two spark plugs at the right hand side of the engine (passenger) are clean and represent the perfect color as seen in all exemples.

 

Plugs at the left side (driver) are both black as in all exemples for

a too rich mixture.

 

What makes this difference ? Both injectors at left kaput ?

What more could be a common reason for both cilinders ?

 

Oh yes , the nearest place of a dealer is 3000 Km away.

It is the only Subaru in the region.

White elefants are more common.............

 

thanks for any suggestion !

Impreza 1800 , 1993 , awd , auto , 100.000 miles.

 

The car is using much more gasoline lately as before , at least 50% more as still 3 months ago.

 

Filters , plugs , spark plug cables ,O2 sensor , all new (oem)

 

Put some cleaning stuff for injectors into the fuel rail for 15 minutes , no improvement.

 

The two spark plugs at the right hand side of the engine (passenger) are clean and represent the perfect color as seen in all exemples.

 

Plugs at the left side (driver) are both black as in all exemples for

a too rich mixture.

 

What makes this difference ? Both injectors at left kaput ?

What more could be a common reason for both cilinders ?

 

Oh yes , the nearest place of a dealer is 3000 Km away.

It is the only Subaru in the region.

White elefants are more common.............

 

thanks for any suggestion !

 

 

It's unlikely that both injectors failed on one side, but to be sure, you could swap the injectors from the left side of the engine to the right side of the engine and see if the spark plug carbon fouling shifts to the other side as well.

 

Do a compression test. It's possible one cylinder bank's camshaft slipped a tooth.

 

Any misfiring?

 

Nathan

Do a compression test. It's possible one cylinder bank's camshaft slipped a tooth.

 

That is my guess.

that's easy enough to check by just taking off ONLY the cam covers on the timing belt cover. 3 bolts each side 10mm bolt head

 

You don't need to pull the whole timing belt cover unless you need to replace the belt. You will probably find it easier to use the main crank bolt (22mm) to turn the crank

 

Just do a side-to-side sprocket to notch check - they both must line up at the same time or you are out of time. At that point, you will be disassembling the front of the engine to replace the timing belt.

 

Get some kind of paint pen (or a bottle of the old "white out" typing correction fluid) to mark the sprockets for the "mark" - it makes it a lot easier to see.

 

IF you slipped a tooth, change the belt because a whole "cam quadrant" length of the belt will be damaged at the tips if nowhere else.

 

IF you slipped a tooth, change the belt because a whole "cam quadrant" length of the belt will be damaged at the tips if nowhere else.

 

Thanks to the helpfull hints , as this weekend is a long one I will check what is recommended by your folks.

I have already a belt for "you never know", so in case .........

The cam shaft positions where perfect , both cams in line with the marks.

I then changed one injector from front left to front right.

 

Strangely ennough , there are stickers on one of the two left and right

injectors , marked L and R. as they are adjusted for r or l ?

 

The result : a lot of smoke out of the exhaust and it seemed to run on 3 cilinders.

 

I measured the resistance of each injector , 3 are in between 13 and 16 ohms , one is 7 ohms ,that is the one with problems.....

I do not know the nominal value , but it seems strange.

Disconnecting it does not change the rpm in idle , all the others do.