Jump to content
Ultimate Subaru Message Board

SPFI running rich


Recommended Posts

Hello..

 

I have subaru SPFI 1987.

 

Excellent spark. New Oxygen sensor.

 

It has always flooded over 4000rpm for extended periods.

 

It is now putting out black smoke and smelling like bad gas.

 

Doesn't idle properly (rpm too low or too high depending on its mood).

 

If I take it for a short trip it will flood at about 3000 rpm. Running rough and smokey the whole time.

 

-I tested throttle pos sensor. OK (idle switch and pos sensor).

-Air flow meter is OK (v+ is good and output changes when I blow in it)

-I havent checked distributor or crank pos sensor yet.

 

No vacuum leaks.

 

disconnecting the coolant temp sensor during idle decreases idle speed (with cold engine)

 

The ECU is showing 14, "abnormal injector output".

 

I'm thinking it's probably 1)fuel pressure too high or 2)injector

is leaking or partially sticking in "open" position.

Link to comment
Share on other sites

probably 2. By "abnormal injector output" they mean electrically; not literal fuel output. The computer has no real way of measuring that.

 

Changing an SPFI injector is easy; just pick one up at the junkyard. Start undoing screws. Its pretty obvious. Be careful with seals and gaskets, and re use if you can, or get new ones for peace of mind.

 

You got FSMs?

 

http://ch601.org/engines.htm find subaru ea82 parts 1 and 2.

 

Included in the second file are directions for testing the resistance of the unpowered injector, so you can "check" the one in the junkyard before you buy it.

Link to comment
Share on other sites

you can also listen to the injector

 

put a screwdriver against it and listen at the handle, you will hear a very distinctive clicking noise if it works properly

 

does the SPFI have a return line for the fuel system? if not, it could be that your fuel pump was changed for a one that supplies to much fuel pressure and thus making it run pig rich

 

if it does have a return line, check the fuel regulator.

Link to comment
Share on other sites

>Changing an SPFI injector is easy; just pick one up at the junkyard. Start

> undoing screws. Its pretty obvious. Be careful with seals and gaskets,

> and re use if you can, or get new ones for peace of mind.

 

I had tested the injector and it was showing good values..

 

I replaced the injector about 2000 miles ago when I first

got the engine running. The one installed in the throttlebody

wasn't opening.

 

I didn't think there was any chance I had another injector

go bad on me...

 

Apparently it was sticking open and causing the engine to

flood.. I replaced the injector with a spare I had and it

still ran rough.. I "reset" the computer by removing power,

and problem is fixed!

 

Thanks...

Link to comment
Share on other sites

Hello..

 

I have subaru SPFI 1987.

It has always flooded over 4000rpm for extended periods.

It is now putting out black smoke and smelling like bad gas.

 

Doesn't idle properly (rpm too low or too high depending on its mood).

 

Replacing the injector (Again) fixed the high RPM floods

and the idling problem.

 

 

Rich

Link to comment
Share on other sites

Please sign in to comment

You will be able to leave a comment after signing in



Sign In Now
 Share

×
×
  • Create New...