91 XT6 FWD has me stumped, please help!

[IraSummers]

The car has 106k miles on it and runs good. I've mainted it well and everything. but last week, it just started something it's never done. It kinda stalls coasting down hill. To some of ya'll it may not seem like much, but I live in the mountans, so everything is either down hill or up hill. Oh, btw, it's an automatic (to be wife's car). Ok, now what I mean by kinda stalling is that it does'nt do it like any other car I've ever seen, where it will just kill off, rpms go to zero and it's dead. It coasts, holds whatever RPM your at (usiualy 2k), but when you start to give it some gas agian, it has NO power, like it's starved of fuel or something. soon as you give it any amount, it starts to sputer a little, rmps slowly drop to about idle and then the car shuts off coasting. It starts fine, runs fine, will idle all day long with no problem and accels fine. I did a tune up on it, replaced the fuel filter, did a fuel injection service on it, and cleaned the Idle control valve, none of which helped it one bit. Now, 2 things that may have something to do with it, I don't know. Just before it started doing this, the speedometer cable broke (replaced today probly) and she got gas at a place that has a history of bad gas.

To me, it does'nt sound like bad gas, becuase that's the only time it does it, every experiance I've had with a gas problem, it caused a rough idle and lots of other things. I'm out of ideas, please help me. I can't afford to go out and buy her a new car, but that's what it looks like. I've taken it to 2 shops and they can't find anything wrong with it. ya'll are my last link.

 

oh, no codes, but when you start it back after (and mabie when it does it), the "POWER" light flashes, no idea what that means...

 

thanks a million!

[idosubaru]

the "POWER" light flashes, no idea what that means...

thanks a million!

the POWER light flashing means the TCU (transmission computer) has a stored code and sees an issue. this may be speedo cable related, but i'm not sure of that.

[idosubaru]

there is an XT6 specific site http://www.xt6.net you will find lots of XT6 information and owners there.

 

2 things come to mind, first is a tune up. distributor cap, rotor and plugs. wires dont' typically cause issue but not a bad idea to replace if they have any age to them. replace all of these items at the same time. use NGK spark plugs only. replace the PCV (use subaru only) while you're at it. though this isn't the cause of your problems.

 

second thing i'd check is the MAF (mass air flow sensor). it's the electrical gizmo bolted to your air box. the only physical way to check it is to remove it and look inside of the sensor box. you'll see very thin wires stretched across the intake air flow. if one of these wires breaks you'll encounter issues similar to what you're having. even if those wires are intact though the MAF could still be causing an issue. get a used one for $25 and swap it out is my suggestion. any MAF from an XT6 will work, Automatic AWD, FWD, Manual, transmission doesn't matter. i think even some 4 cylinder MAF's will work, but no worries an XT6 MAF should be easy to find.

 

not much of chance of this being an issue if the check engine light doesn't come on, but the coolant temperature sensor (the one next to the thermostat housing and coolant housing - to the left of the alternator) causes all sorts of issues in over half of the dozen XT6's i've owned. look at it and see if the plastic harness is in good shape. check the connections inside of it and on the sensor that screws into the block. any green corrossion or bad contacts there will cause issue. but they will usually show up at idle and start up, so this most likely is not it.

 

at 106,000 miles this thing should be about half way through life, so i'd get it fixed. they run forever (like most soobs of this vintage). unless it's transmission related (doubt it) i can promise this is a sub-$50 fix with a 99 percent certainty. i've owned 10 or 15 of these things, though none were FWD.