93 Legacy won't rev in neutral at wot

[whippet]

The car is a 93 legacy lsi auto awd.

It will not rev in neutral or park when idling. If you step on the gas 1/2 down it drops to about 600 and stays there and never revs any higher. If you give it a little gas it will rev. When driving it has no power and will not start going. if you get it moving then give it a little gas then it will eventually get moving. It has no power at all. It has no codes or the CEL is not on. I have replaced the fuel pressure regulator, the TPS, MAF, ECU, (these came off a running car). Ran it with the exhaust dropped in case had a plugged cat. None of these things made any difference. Checked the fuel pressure and it was ok.

[nipper]

One of two things. The most common is a clogged catalytic converter. Hit the cat with your hand when its cold and see if it rattles.

 

Second one is a bad torque convereter, but in a subaru thats really rare.

 

 

nipper

[OB99W]

The ECU could be defaulting to a "fail safe" mode (although it would usually light the CEL and there'd be codes); some of those modes cut off one or more injectors. If you haven't already seen http://endwrench.com/images/pdfs/Fuel.pdf , I suggest you read it through.

 

A few questions:

1) Did the parts you swapped in come from the same model/year?

1) Does the CEL light with ignition on, before starting the engine?

2) Does the engine stumble if you try to accelerate, or just refuse to rev?

3) Is there any difference between cold operation and when the engine is warm?

[OB99W]

Another thought -- besides exhaust restriction (which was already checked for), intake problems can of course severely limit the engine's ability to "breathe". Blockage or even holes can be a problem. See http://endwrench.com/images/pdfs/EWMAFAug05.pdf , for example.

 

A vacuum gauge (yes, I'm beating that horse again ) might tell you a lot about what's going on. See the links in my previous post in another thread: http://www.ultimatesubaru.org/forum/showpost.php?p=596419 . If you do vacuum testing, let us know the results at idle and with the throttle opened further.

 

One other possibility is an electrical problem. Corroded or loose connections (grounds and otherwise) can sometimes cause strange problems with the engine management system.

[whippet]

Found out what was wrong with the car. I tried everything that I could think of. I went and asked a friend who owns a shop. I told him that it would idle but when step on it would drop to 600 and stay there. He then asked me if it had no power on the road and answered that it didn't. He then told me that he knew what was wrong. He told me that the crank pulley had came lose and then destroyed the key way in the crank. He then took me into the back and showed me a Legacy with the same problem. It really wasn't what I wanted to hear. When I tore my daughter-in-law's down the crank was ruined and the sprocket on the crank would turn freely about 5 degrees. Have it out and a spare engine to get ready to put back in. The engine was out of a 5 speed so I have to change the flywheel and put all the parts back on that I took off for this engine.

 

Thanks everyone

[OB99W]

Found out what was wrong with the car.[...]When I tore my daughter-in-law's down the crank was ruined and the sprocket on the crank would turn freely about 5 degrees.[...]

Congratulations on finding the problem, and condolences on what has to be done to resolve it. A loose crank pulley can be a real problem and cause significant damage if not caught soon enough. It doesn't tend to occur unless the pulley bolt wasn't sufficiently tight, and that typically happens when the torque spec isn't met during timing belt work. Before things get too bad, there's sometimes a clue: the engine-driven accessory belts (alternator, PS, A/C) will loosen, often causing strange noises or charging/steering/cooling problems.

 

Since the ECU needs timing information from the crankshaft angle sensor, if the sprocket is loose the pulses don't relate to actual crank rotational position and the timing of both ignition and fuel injection will be off. At best, the ECU uses the data it gets or defaults to a fail-safe/limp mode. That explains the symptoms you experienced.

 

I suppose I should add "timing light" to my suggestions of "old time" test gear that's still useful when OBD codes don't do the trick.