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Starting problems- PLEASE HELP!


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Link to Sound my car is making (MP3 file)

Hey guys,

 

I have a 1990 Subaru Legacy 4wd. This morning my dad took the car to go run some errands. On the return trip, she started acting real weird. When my dad got to a red light, the cars RPM's dropped and the car cut off. Now this has been happening for awhile when I cold start the car and drive it immediately, but I assumed that this was the case. My dad said that it wouldn't crank over at all. So we towed it home and I am here asking for your help. My dad wants to get rid of the car, but I want to fix it and keep it just a little bit longer. Here is a little history of the car so you'll have an idea of what I'm working with...

 

149,860 mi, Tranny won't stay in park, car rolls (have to use parking brake), Tranny slips in 1st gear when cold start in morning, and shifts fine after driving it for a few miles. Check engine light has been on for awhile too. (changed O2 sensors, one of the causes of the light, but have yet to change the canister purge that came up on the last diagnostic). I have attached a link to this message at the top so you can hear what sounds she is making. The guy that we towed the car home with (from AAA) said that maybe the engine had blown or the timing belt has busted. I don't know for sure, but maybe it's just a sensor or something (I hope:( ) Listen to the MP3 and tell me what you think. I need this car to go to school and work, so If I can do anything to fix it, let me know. Thanks.

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I'm no expert just a shade tree mechanic. So here's my opinion for what it's worth (2 cents to be exact...)

I hear an engine that's quitting immediately after having started. Engine turns over for a second.

What it would tell me if it were my car is that the engine is getting insufficient fuel volume or pressure. Like the pump get just enough fuel together to have the engine start but it starves just has it's getting to it's idle speed.

What's the cause of that? I would guess bad fuel pressure regulator, clogged fuel filter, clogged fuel line, bad pump, clogged pump intake.

Hope someone with a better ear than mine listened to your recording.

Nice accent by the way. Must be warmer where you are than here!

Good luck! I'm not completely familiar with US states acronymes But I guess GA must be Georgia?

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I tend to agree with Frag, that this sounds like a fuel-starvation problem. I had a similar experience with a 1968 Ford Mustang (oh, those were the days!). But that was a carburetted engine. The fuel-filter was clogged, but allowed just enough fuel through to slowly fill the float-chamber; hence the car would start for a few seconds, running off the residual fuel in the float-chamber, and die a few seconds later. If I cranked it hard, it would restart and then die again. Since we were miles from anywhere, with 3 small kids in the back, I had to do something quickly. So I borrowed one of my wife's knitting needles, and pierced a hole through the fuel-filter element, reassembled it, and away we went!

 

Could this type of temporary fuel-starvation happen on a fuel-injected engine? I don't know.

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If this car had crank angle and cam angle sensors, they are used in tandem. one as a check against the other, if your cel was on because one was bad, AND THEN the other one goes, that might cause this symptom. Do subies have a 'run resistor' that is bypassed during satrting? maybe it finally burned up - though the symptom is more like 'cranks - fires - dies when key released' kinda thing.

 

physicusman...if you don't give us more info. I'm sending snotty over to rip off your TB covers!

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Forester, never tried it myself but the manuals (Haynes and Chilton's) tell to unplug the fuel pump, start the engine and let it starve to relieve fuel pressure before replacing the fuel filter for example.

So I guess a fuel injected engine can run at leat for a very short time on residual pressure.

That does'nt prove anything but only makes it a possibility.

Hope the cold does'nt hit you in the west as soon as it's hitting us here in the east.

Cheers!

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If you have fuel get a meter and check the coil pact, a good manual will tell you how. Also are you sure the transmisson is not causing it to stall. Our 92 Buick with auto trans. would stall when we stopped at stop sign, just like a standard trans would if you stopped with out pushing clutch in. Had transmisson shop put in some valve and fixed it.

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yep, sounds like a fuel starvation problem. Start by checking your fuel systen to see if you're getting fuel to the injectors. If you are, then prceed to checking to see if you have spark. If both of those are in fine shape, time to pull the TB covers off and see if your timing is screwed up. If its not and it all looks fine.......well......time to get a gen 1 wagon:brow:

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Three things are needed to run an engine: air, fuel, and spark.

 

Looks like you guys have talked about spark and fuel, but not air.

 

 

AIR:

 

My 1993 Legacy had a odd occurance with its idle air control valve. At some red lights it would idle very erratically, and sometimes it would stall. Sometimes I could prevent it from stalling by opening the throttle, other times opening the throttle would cause the engine to stall. The ECU stored no codes, but the dealer diagnosed the idle air control valve. It was expensive, so I tried disassembling and cleaning the valve with brake cleaner. I put it back together and the car ran fun for more than 300,000 more kilometers. I am not sure if the idle valve is the same on automatic and manual transmission cars, sometimes they are different.

 

The idle air control is on the passenger side of the intake manifold. It is a round gray (may be another color on your car) plastic component about the size of a 35mm film canister with two screws holding it in place. You will note that if the screws are loosened it may be adjusted. If you want to clean it, mark the part so it can be replaced correctly. Remove it and you will find a metal round valve that is magnetically opened and closed. Clean the cap and valve with brake cleaner and reinstall.

 

This trick worked for me, but it may not always work. I have heard that moisture gets into the valve, freezes and then cracks something in there.

 

Will your car start and run ok if the throttle is stlighly open, but then stall or run erratic with the throttle closed? If so it is most likely, but not always idle air control.

 

Idle Air Control failures seldom store an ECU code, unless the electric wire is disconnected. There is no provision in the valve for it to validate that the requested opening angle matches the actual opening angle.

 

You could have a bad air flow meter, but the ECU will usually be able to use its internal air/fuel map and other sensor readings to compensate. The ECU will also store a code for this failure.

 

FUEL:

 

If the engine runs ok at speed with no noticable loss of power your fuel pump is probably ok. Your fuel filter could be clogged, but it is somewhat rare for a fuel filter to cause an engine to stall unless it has ice in it.

 

Never disconnect a fuel line and turn the key to on, it is not a valid test of anything... and it is dangerous.

 

You can tell if the fuel pump is working by having someone place their ear on the cargo area floor immediately behind the passenger side rear seat. When the key is turned to on, the fuel pump will run for 2 or 3 seconds to pressurize the fuel line, you should be able to hear this. No noise = bad pump or wiring to it.

 

After you determine that the pump is at least priming the fuel line, you must check fuel pressure. Do this with a fuel pressure guage capable of reading up to 100PSI.

 

Release the fuel pressure by disconnecting the fuel pump wiring harness under the back seat bottom (I think this applies to all Subaru's). It is on the passenger side below some insulation. Then start or try to start the engine. This will release the pressure. Allow engine to die (if it started) and then reconnect the fuel pump wiring.

 

Install a T pipe fitting into the fuel system between the lines into and out of the fuel filter (easiest way). When the key is in the on position (do NOT start the engine) the pressure must be above 35PSI (not positive, but 35PSI seems to ring a bell). I think 47 PSI is normal with a 35 PSI minimum for your vehicle (it will be in the Haynes guide).

 

If no pressure, you have a bad pump or blocked line.

 

If low pressure you have a blocked line, bad pump or bad fuel pressure regulator.

 

Note that since we bypassed the fuel filter by installing a T for the fuel pressure gauge, the filter can not be determined to be bad. If it is more than 2 years or 30,000 miles old, just change it....

 

SPARK:

 

If the engine was running fine at 3000+ RPM without storing a misfire code in the ECU, your coilpack, wires and spark plugs are ok. Coilpack failures almost always occur at high RPM leading to misfire, at lower RPMS, they just seem to work ok.

 

 

I would diagnose any stored ECU codes, as sometimes the ECU will go into limp home mode, which can cause starting or stalling problems.

 

A bad purge control can cause stalling!! As can a problem with the EGR valve.

 

Your tranny slipping when cold could be normal. In cold weather the ECU will signal the TCS to slip the transmission. With this slip the engine and catalytic converter will heat up quicker to reduce emmisions. If you have a bad O2 sensor or catalytic the tranny may be in the slip mode for too long or in some cases all the time. The ECU will terminate the cold temperature TCS slip signal as soon as it processes good data from the O2 sensor and the engine temp reaches normal.

 

The sound you recorded doesn't tell me much. Other than it sounds like the starter is straining to crank the engine. You could have a weak battery or a warn starter.

 

Or Perhaps a blocked catalytic convertor. Some Subarus suffer from blocked catalytic convertors, which will cause the engine to start to run extremely bad, and then stall and not be able to be restarted. I see this all the time on old Subaru's, which yours would qualify as being.

 

I would feel for exhaust pulse at the tailpipe when the engine is cranking. If none are felt I would disconnect the Y Pipe from the heads of the engine and see if the engine starts. If is starts shut it off immediately, as you have identified a clogged catalytic convertor and running the engine with the Y Pipe disconnected is extremely bad for the engine.

 

A new catalytic convertor for your car is very expensive, at least $600 from Subaru. You might find an aftermarket model for lot less but the afternarket ones that I have seen are not well built. How long you want to keep the car will determine which one to get. If your car ran really bad with little or no power for 5 or 10 minutes and then died and could not be started, this is the likely cause. It could have been immediately verifyed because the catalytic converter will be glowing red it is blocked.

 

I don't think timing is a problem. Your car has a crank and cam angle sensor and would detect this. You can check timing easily by removing the left and right timing belt covers (nothing else needs to come off). Turn the crank with a 22m wrench clockwise to TDC (notch on the crank pulley matches marks on center belt cover. Note the location of the camshaft pulley marks, they should be at 12 o clock matching the marks. If the pulley marks are at 6 o clock, rotate the crankshaft one full revolution again to TDC. The cams should now read at 12 o clock. Remember that the crankshaft rotates a twice the speed of the camshafts, which is why the camshaft can read 12 o clock or 6 o clock.

 

Hope this helps....

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You already have a code for the evaporative cannister, right? Go ahead & check it and call us in the morning. With that high of milage the can should be about full and if it is it backs up into the float bowl on a carb and into the fuel on FI. Let us know what you find there before you tear the engine apart and disconnect the exhaust. Do the easy stuff first.

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