engine cuts out when starting and while driving at any and every speed!

[earthkin]

I have pretty much the same problem with my '92 LSL. I have error codes 23, 24, & 28, which doesn't narrow it down enough really, since these could be the "Air Flow Sensor," "Bypass Air Control Solenoid Valve," or the "Knock Sensor 2 (LH)." I took it into the local Subaru mechanic (S-Wings), where they read & cleared the codes, but the codes didn't come back at that time, so we didn't do anything. Since then, the codes have come back (it has died many many times). S-Wings said they have seen problems with a faulty Knock Sensor causing similar problems. Has anyone else seen this with the Knock Sensor?

The dying happens randomly: at medium revs, low revs, when starting, when idling, when cold, when warm: basically, anytime. It originally wasn't running rough, but as the problem has been getting worse, it seems to run rougher. Also, sometimes it barely runs, has little power, and then dies. On the alternator possibility: I have noticed my lights dimming sometimes when my turn signal is on, but nothing else. The battery is something around 750cca (yes, I bought a big one) and is fairly new (around 6 months). About all I've done is run 1/2 tank of Fuel Injector cleaner treated gas through it, and drove it about 5 miles with Octane boost, since I was having trouble getting it home the last time. None of this seems to have made any difference.

[vkykam]

Code 24 is the IAC, and can cause low idle problems. Code 23 is the MAF, and can affect it at all ranges.

The knock sensor wouldn't cause the engine to cut out as you have described.

I know I'm repeating myself here, but try the MAF first. There was advice from another thread that a MAF from an Impreza would work as well, so it should help in hunting one down at a reasonable price from the wreckers.

Good luck.

VK

Originally posted by earthkin
I have pretty much the same problem with my '92 LSL. I have error codes 23, 24, & 28, which doesn't narrow it down enough really, since these could be the "Air Flow Sensor," "Bypass Air Control Solenoid Valve," or the "Knock Sensor 2 (LH)." I took it into the local Subaru mechanic (S-Wings), where they read & cleared the codes, but the codes didn't come back at that time, so we didn't do anything. Since then, the codes have come back (it has died many many times). S-Wings said they have seen problems with a faulty Knock Sensor causing similar problems. Has anyone else seen this with the Knock Sensor?

The dying happens randomly: at medium revs, low revs, when starting, when idling, when cold, when warm: basically, anytime. It originally wasn't running rough, but as the problem has been getting worse, it seems to run rougher. Also, sometimes it barely runs, has little power, and then dies. On the alternator possibility: I have noticed my lights dimming sometimes when my turn signal is on, but nothing else. The battery is something around 750cca (yes, I bought a big one) and is fairly new (around 6 months). About all I've done is run 1/2 tank of Fuel Injector cleaner treated gas through it, and drove it about 5 miles with Octane boost, since I was having trouble getting it home the last time. None of this seems to have made any difference.

Would the Idle Air Control unit possibly cause my SVX to shift poorly at low rpms? Cause that is what she seems to be doing. I went and cleaned my MAF as well as the Throttle Body, and the dying has decreased in frequency, but shifing is poor.. As I described before, going from 1st to 2nd, and more so from 2nd to 3rd, the rpms will jump up and the car will act as though I had slipped her into neutral for a few seconds before the rpms drop and the next gear catches) This only seems to happen at low speeds/low rpms (when I have only depressed the accelerator pedal lightly). When I use more gas from 1st gear, she shifts fine, if not a little less smoothly than I would like. Could this be related to the IAC? Any other ideas? Would a simple transmission rebuild be the only solution? If so, I'll have to shoot the car through the hood.

[vkykam]

If your RPMs are "flaring up" in between shifts, I'm afraid that's not good news.

You could cross your fingers and change your tranny fluid, but it may end up being the transmission.

VK

I've been having the same problem as many of you guys. It started about 6 months back and only did it once in a blue moon. Then once a day. Now everytime I drive some where I have to restart the car about 10 times. Dealer said it was a coil and charged me 420.00 to change 1 and all the plugs. No Good! Then they said it was the fuel pump. Well I learned my lesson and ordered it and installed it myself. Still no good! Now heres where it gets tricky. I did see no fuel pressure when we tested the line before I replaced the pump. But changing the pump didn't help so is there a control module or relay for the pump that could be bad? According to Subaru Parts there is. But I have no idea where it is? I'm going to try the MAF solution first since I found a used one for 75.00 . Wish me luck! I Also tried pulling the codes from the ECU accrding to the instructions I found here but got no reaction so I think I must be doing it wrong. Could someone send a picture of the diagnostic plug with the wire inserted into the correct hole for newbies like me?

[Clydesvx]

It's probably the Mass Air Flow Sensor. It's the thing in your air intake. According to my Subaru guy it only shows up on the diagnostic computer if it is hooked up when it fails. I got mine from SUBARUPARTS.COM. I saved about $100 on the part and installed it myself. My failure wasn't as often as yours but the symptoms were the same. Riding down the road the engine would die. A slip into neutral and a turn of the key and I was up and running until the next failure!!!

No problems (knock on wood) since the MAF sensor was installed.

Just to be sure, why not WD-40 the MAF sensor connector and reconnect. Maybe someone loosend the connector when they were playing with the coil or plugs.

Clydesvx

[svxistentialist]

Originally posted by Lasher
Would the Idle Air Control unit possibly cause my SVX to shift poorly at low rpms? Cause that is what she seems to be doing. I went and cleaned my MAF as well as the Throttle Body, and the dying has decreased in frequency, but shifing is poor.. As I described before, going from 1st to 2nd, and more so from 2nd to 3rd, the rpms will jump up and the car will act as though I had slipped her into neutral for a few seconds before the rpms drop and the next gear catches) This only seems to happen at low speeds/low rpms (when I have only depressed the accelerator pedal lightly). When I use more gas from 1st gear, she shifts fine, if not a little less smoothly than I would like. Could this be related to the IAC? Any other ideas? Would a simple transmission rebuild be the only solution? If so, I'll have to shoot the car through the hood.

As VK says above, Lasher, this is not good news, particularly if it is caused by the tranny slipping.

However, another avenue to check first which is cheaper would be the TPS, the Throttle Position Sensor. This is a potentiometer, and the rate at which it changes voltage from 0 to 5 tells the TCU how and when to shift. It can go faulty, give signals difficult to interpret, and will give the revving you describe at low speeds. You should check this out first. A new one costs about
$150 from Subaru.com. Remember, if it is the TPS and you do not fix it, the continual revving will be slipping and wearing the tranny clutches.

Joe

Well as some of you may know I was having an awful time with my SVX cutting off. I tried replacing the fuel pump and ingnition coils and spark plugs with no help. Finally after reading these posts I ordered an Airflow meter and sure enough the problem went away.

hmm well this thread has moved along a bit since i last posted... seems unanimous decision is to change the MAF. Did you get one yet Lasher?

However, at first I think I will just clean and tighten the alternator connections, to see if that helps.

My revs do flare a little between changes in the lower gears, though I hope this does not mean the transmission is in trouble. It was only rebuilt 25k or so ago.

I had considered there was a problem with the TPS, but I think there is something over-riding the throttle when the car cuts out. I think this, because the POWER mode light still comes on when i pump the accelerator during the cutting out process (as described in my previous post). So the car still knows i stamped on the gas, but something else prevents the engine revs from increasing.

Another thing, when the car is cutting out, it doesn't 'coast' as i previously described it. It is more like I simply took my foot off the gas completely. It is not that the tranmission is disconnected, like driving a stick-shift with the clutch in. There is noticeable engine braking just before the engine dies, if the cutting out process occurs in second gear.

If the pre-cutting-out 'throttle death' happens on the freeway with cruise control set to 80mph, the car will start to slow down from 80, and to compensate, the cruise computer presses the accelerator hard to the floor. (Usually to no avail.)

gabe

[earthkin]

I replaced the MAF with a used one, and am declaring victory. (This is the 2nd SVX with the same symptoms that the MAF fixed, by my count.) I bought a used Air Flow Sensor from a parts place that I found on Car-Part.com (details below), it was only $40 + $10 shipping. Only problem was I had to buy it COD (used a money order from the Post Office) since they didn't take plastic. Too bad all SVX problems aren't this cheap & easy to fix...

Part name: Air Flow Meter
Web Portal: Car-Part.com: Used Auto Parts Market, http://www.car-part.com
Vendor: All Foreign Auto Parts
My experience with them: delivered in a few days. Part was dusty, but cleaned up easily, and works. Hey, at roughly 20% cost of a new part, a great deal.
Tip: look for an ad that says "Tested"
Part Number: 22680
... yes, they have more available.

[kpcusa]

Hey, guys,

I am experiencing the very same problems reported in this thread. Twice I have gone to the dealer (who has a mechanic with 22 years of Subaru experience working on the car) to find the source of and resolution to the problem. The engine quits when accelerating rapidly, decelerating rapidly, in nromal traffic or when idling (basically anytime). It will also "buck" at times when on the highway. The dealer has been able to replicate the symptoms but no check engine light appears; hence no stored codes. The dealer pulled the codes prior the last visit but none were stored.

I had them replace the fuel filter just to rule it out this last time around. They also swapped out the MAF from a '92 in the shop at the time (for a power steering pump) and the stalling still occurred (the owner of the '92 has no such problems I am told).

The car has a new fuel pump and filter, power steering pump and timing belt.

It's a smooth runner with the exception of the occasional stalling or bucking. It will idle below 1,000 frequently and just stall out.

Any input would be GREATLY appreciated.

Ken

[kpcusa]

Finally fixed!

A $45 MAF air flow meter (used plus $10 S&H from Weber Bros. Auto in PA) was all it needed - it runs like a champ now.

I see a lot of rough running and stalling issues that can be traced to this sensor.

It's great that everyone reporting the same problem has had such high success rates with replacing the MAF. A real success of this website.

I am ordering my MAF today from a salvage yard, and i see from my service manuals, that the MAF sits rather conveniently atop the engine - when i get the used MAF in the mail, are there any complications with installing it myself???

I don't have much mechanical experience... but williing to try! Feedback appreciated before I get my hands dirty...

Gabriel

[kpcusa]

Gabriel:

It is a snap, de-installing my old mass airflow sensor and replacing the new one took me maybe 20 minutes. If you are all thumbs and not at all mechanically inclined it may take an half hour; maybe an hour. It's not a complex procedure.

I suggest you go to http://www.geocities.com/kuleshoff/MAF.htm and review the SVX instructions prior to your install.

Good luck.

Ken