engine stalling when cold...

[vettn]

I just bought a 94 SVX LS couple of days ago. Awsome car. As far as I can tell it's got the cone K&N filter, and has the muffler removed. Not sure if anything else was done to it. But anyway, when I first start it in the morning, it starts right away, but the idle goes up, then down, then it stalls. If I crank it over one more time it starts just fine. It also idles very smooth. Anyone know why that is happaning? Thanks.

[Aredubjay]

The "up and down" is the ECU "searching" the "system" and doing a diagnosis. As far as the stalling, I'd suspect the MAF sensor, but, don't hold me to that, especially if it idles fine once it has started. Apparently, the ECU is hitting something during the diagnosis process that it doesn't like. Are you getting any "blinks" from any of the idiot lights in the instrument cluster? You might just try disconnecting the battery overnight and let the ECU clear its brain, so it has a fresh start on your next start-up. I'm not sure about this, either, but, the cone filter may have something to do with it (possibly allowing too much air on first start-up, the ECU senses it and adjusts, just intime for stall, then, on second start, it reads the "correction." -- just thinking out loud).

[vettn]

Thanks for the help. There are no idiot light flashing at all. I will try disconnecting the battery tonight and see what happens. Thanks.

[Phast SVX]

Theres no muffler at all? That could be your problem, wiht a fualty MAF sensor and almost no backpressure at all it dosnt make for a happy engine

[vettn]

Yeah, I haven't had a chance to look at it completely yet, but I know for sure that the guy took out the muffler and put in straight pipes instead, and I do believe that he also took out the resinator. (Not sure there was one on those cars, but I think there should be)

Wouldn't a bad MAF sensor show error codes, and check engine light?

[Rev Hard]

two replies....
<<but I know for sure that the guy took out the muffler and put in straight pipes instead, and I do believe that he also took out the resinator.>>

LOUD!!!

and....

<<Wouldn't a bad MAF sensor show error codes, and check engine light?>>

YES

[immortal_suby]

when you clear the ECU memory by disconnecting the battery remember that at the first startup, do not touch the accelerator, let the car warm up for 10-15 minutes until at normal temp, then shut it off and drive as normal. also - leave the cover for the radio open.

[deligeds]

I also have a 94 w/ a cone air filter, and I've had the same problem for years. It's worst in the 20-30 degree (F) temp range. I've tried many things to resolve the issue. Nothing worked 100%, but you might try disassembling and cleaning the throttle body and idle air control valve. Though I'm not sure that that was the key factor, it seemed to help. My SVX no longer stalls, but often comes dangerously close. Let me know if you find a way to fix it completely.

[vettn]

Well, I disconnected the battery last night and let the car sit overnight. This morning I reconnected the battery, and crancked the car over without giving it any gas and for the first time it didn't die. I sure sounded like it wanted to, but kept on going. Ran it for about 15 to 20 minutes. Shut it off for couple of minutes, restarted without a problem and drove to work. Have to wait and see how it starts when I go for lunch. It normally took two tries after the car has been sitting for few hours.

[Aredubjay]

If the problem reoccurs, you might try putting the standard airbox back in, that is, if you're not just perfectly bent on having the cone filter. That may cure it.

[vettn]

I do like the cone filter, and I would try the stock air box, but since I bought the car with the cone filter already installed, I don't have the stock air box. I'll have to see if the problem is still there, I might modify a stock lid from my old car and put it in (They look almost identical).

[deligeds]

Based on my experience, I don't think that the cone air filter is the problem. My SVX was having the problem long before I replaced the factory airbox.

[vettn]

Well, I tried clearing the ECU like you guys suggested, and it lookes like it worked. For the last three or four days, the car started on the first try and didn't die. Thanks For All Your Help...

[svxxx26]

I was wondering - Immortal Suby - what the reason was for the procedure you described in resetting the ECU.
This goes beyond just unplugging the battery overnight. Do you know any of the technical reasons for warming the car up, shutting it down and restarting?
I plan on trying it out soon to see if it has any different effect.

[immortal_suby]

A tech or suby engineer could probably explain the technical reasons, I could only speculate. From what I have read, on a turbo subaru you reset the ECU and then beat the daylights out of the car immediately. On a NA subaru you let it sit for a complete cycle of warming up and then shut it off, and then you start it up again and beat the daylights out of it. It has something to do with how the ECU learns your driving habits.

[1994SubaruSVX]

i have reset my ecu several times and my car still idles weird every now and then?? sometimes it does it and sometime it doesnt?? i am going to take it to the dealer and have them check the MAS and the ECU. i added a k&n filter and of course i have the true dual exhaust so maybe my car is just really confused. either that or it has a very slow learing curve. HELP!!!????