subaru dealers can't even fix this one..

Hi everybody.. I've posted on this problem in my car before but sadly every time I thought it was fixed it turned out not to be. Ok so my car has had some problem with the engine cutting out the last two months. It happens usually when the car is up to normal running temp. and can happen at slow speed or high speeds on the freeway. When it dies the rpms drop to zero and the car begins to coast. If dropped to neutral the engine starts right back up and continues to go. I have had the fuel pump, fuel regulator (I think), and both 02 sensors replaced. The MAF has been tested fine. The engine keeps coming up with codes of #32 and #37 but the local subaru dealer can't figure out what is wrong since the o2 sensors have been replaced and tested. (btw the mecanic there owns 2 svx's so I'm shocked this can't be figured out.) I have seen the previous post about people that had the same problem as me but if the MAF is tested fine could this be something different? Thanks and sorry to fill the tech forum with my probs.

[SVXRide]

check the gas cap...it almost sounds like the engine is being starved for fuel - does it cut out "soft" or does the idle get rough and then the engine cuts off?

well when it cuts out its one of two things. Either the rpms just drops to zero instantly with no warning at all, or the car will sputter a few times then drop to zero. (note even when the engine dies and all the lights come on the headlights and stereo will continue as if nothing happened.) The subaru dealer stated that the fuel pressure was good at 28-34 PSI and the vaccum fuel system had no leaks. I could check the gas cap but if the fuel pressure was good when they tested it would that rule out anything in the fuel system? (especially considering that almost everything having to do with it has already been replaced hehe.)

[SVXRide]

It's just a shot - if the tank isn't venting correctly it could be building up a vacuum which would cut off the flow of gas. Is this happening no matter what the level of gas you've got in the tank? Does it happen if the car is just standing still at idle?
The other thing is seems to remind me of is when I had a bad capacitor in a MSD unit in a Camaro I built - turns out the capacitor would ground out within the MSD unit under certain driving conditions - the car would die, I'd pop the trans into neutral, and it would start right back up. Sooo, you might want to check the electrical system for an intermittent short - start jiggling wires to see if anything is loose (start at the battery and work back).

p.s. given that the system is throwing O2 sensor codes and the sensors are supposed to be good (you have had them check to make sure, right?) - you might want to check the circuit the O2 sensors are in for a short.

the problem seems to happen with a full tank or empty. Also it does not happen when idling, only when the car is in motion, but it does not have to be going fast.. 10-20 mph will do it. I think you are on the right track with the electrical connection thing since the problem happens when the car is warm (wires warm and expanding) and happens at random times with random speeds. (wire moving around during driving). If I can't find it I'll have to take it back to the subaru dealer to have them look at it again, though they handed it back to me this time with their hands in in the air with no idea on what was causing it.

[lee]

Seems likely to me this is an electrical problem & intermittent electrical gremlins suck (believe me I know, having an old Norton with Lucas electrics.....). Since the lights & stereo work I think you can eliminate the battery/alternator issue (car restarts OK) and probably the ignition switch (car starts, radio & dash lights respond appropriately), but I'd still search the forum on the ignition switch and read about loose connectors.

A couple of freebie things I'd also try would include:

look in the How To and run the diagnostics plug thing to see if any codes are stored for the ECU.

get under the dash and try unplugging then replugging in the ECU.

Same for connectors under rear package tray (between speakers).

might try to open up the back seat area and remove the plate hiding the fuel pump, listen for it working or not when it dies.

Check connectors under the hood like MAF, and the various temp sensors.

You could buy some contact cleaner at Radio Shack and give a blast to each of these.

I wonder if the starter interrupt relay could be failing, any issues with the security system?? ...some work, but the relay is somewhere under the dash and you could unplug it as a trial.

Good luck.

Check the ground on the back of the igniter. I've had trouble there before on 2.5L motors. I believe the igniter itself grounds to the chassis through its backing plate. I forget whether the system on the SVX is the same or not, worth a check though.

[lee]

chiming in with Porter, I had forgotten the universal adage that the vast majority of intermittent electrical problems turns out to have a grounding issue.

Well the only other electrical thing that recently has gone wacky is the dash fans no longer working for the climate control (in any mode). I don't see how the two would be related but eh.. who knows. I'll run my multimeter all over this thanksgiving weekend as well. Thanks for all the hints, Worst that can happen given time is that the car has this problem occur much more often which would be a blessing as the dealer could finally have it happen there.

[svxistentialist]

Justin

This is just a thought, or a wild suggestion[well, maybe not so wild ]

It could be you have a loose connection or bad earth on your igniter circuit, as suggested by Porter and some others. This is probably momentarily killing your ignition, and you get shutdown.

Your car will only restart in Neutral because of all the relays that allow it to start only in P or N.

The reason I think you are getting O2 sensor codes, with ignition off and the engine still turning, unburnt fuel is passing them, and the readings are off scale for the ECU.

It is also likely the dealer is not finding this because the dealer is trying to find the problem on the ramp, as they all do, and the problem only happens under movement and vibration when the car is underway. A bad or loose ground to the igniter or associated capacitor as suggested by SVXride would be where I would start looking.

Best of luck with it.

Joe

[michael]

I had this problem after I changed my o2s I used a universal bosch. IMO you need to use the o2 for the svx different wire length=different resistance. Make sure they are not universals you can tell by the connection type it should match the stock plug, also check to be sure there plugged in properly. Good Luck