1997 Subaru 2.2L - Stumbling & stalling

[sw99]

1997 EJ22 engine with 149K.

This mostly happens when it's hot outside. The engine will idle fine one minute and then start stumbling and almost stall out the next. When this is not happening (more and more frequently these days), the engine runs perfect, with no other issues. I was thinking maybe I should try cleaning the IAC valve and maybe toss in a new gasket but I am not really sure? MAF sensor maybe? Any other things to explore, this is getting frustrating. Thank you.

 

[Torquejumper]

I would take a look at the MAF and crank sensor.

 

[sw99]

Also remembered that I have been noticing that the exhaust smell is stronger than usual. I have no idea if it's related or not.

 

[sw99]

Is the crank sensor the same as the CPS sensor?

 

[tomcat27]

yes. Crankshaft Position Sensor.

 

[tomcat27]

unfortunately I am not familiar with the 4 cylinder Fuji motors, but on most cars I would recommend cleaning the throttle body, back of the throttle plate, and also the idle air control valve - removing carbon from all of them.

 

[meep]

engine light on? that's an obd 2 car. bulletproof motor. is the stumble rhythmic (like a failing coil pack) or chaotic (crank sensor)? There is a cam sensor on one of the banks to find cyl #1 as well as a crank sensor to find TDC. The crank sensor is a bit of a job to get to.

Does it do this while driving? (plugs, plug wires, coil pack)? Temperature related?

The crank sensor is a bit of a job to get to.
this is by memory--
1. pull serpentine belt
2. pull fans. maybe air filter too?
3. remove timing cover
4. use breaker bar to remove bolt on crankshaft pulley (I put the 5spd in 5th to lock the engine. don't know how to lock if it's an AT)
5. tap pulley off, no puller required
6. remove center timing cover
7. you can prolly see the sensor at this point.

you may not have to do all that--- you've just done most of the work to replace the TB, water pump, remove/tighten/change o-ring and crank seal on oil pump... so do it while in there. If you do decide to go that route, BUY THE OEM T-Belt!!!! learned that the hard way with this motor... the OEM belt is much sturdier than aftermarket.

m

 

[sw99]

No check engine light and it does not do is while it's actually driving, just at idle.

I was thinking of trying to clean the MAF and the TB today and see if that does anything. I don't want to open up the IAC until I get a new gasket.

Can it still throw a code if the check engine light is not on?

Thanks folks.

 

[mechtech2]

Originally Posted By: tomcat27
unfortunately I am not familiar with the 4 cylinder Fuji motors, but on most cars I would recommend cleaning the throttle body, back of the throttle plate, and also the idle air control valve - removing carbon from all of them.


This is very good advice. This should be done no matter if it is the primary problem or not.
Have the car checked for codes at an autozone for free.

 

[sw99]

OK, thanks everyone.

Broke the MAP sensor trying to remove it so I had to pick one up at the junk yard. I also found a newer MAP sensor as well. Not to mention the fender, bumper cover and headlights I ended up getting also...

Ran good while I briefly moved it, but too early to tell if it's fixed yet. Before I installed the replacement MAP sensor, I cleaned it really well with the MAP sensor cleaner. I will order a IAC gasket from the stealership and replace soon.