81subaruglguy Posted April 15, 2011 Share Posted April 15, 2011 so we just picked up a 92 legacy had to hot wire but it fired once and ran for i would say 10 seconds then wont run again. one plug wire needs to be replaced but that shouldnt cause it to not run but is this a normal problem and im thinking its a bad TPS or MAF senor or something any ideas Quote Link to comment Share on other sites More sharing options...
bstone Posted April 15, 2011 Share Posted April 15, 2011 There is insufficient information for a meaningful answer. How many miles? Manual or AT? How old is the gas? Did you check for spark? Any lights on? Quote Link to comment Share on other sites More sharing options...
81subaruglguy Posted April 15, 2011 Author Share Posted April 15, 2011 it has like 135000 M/T has spark gas is good fuel pump is new has good compression Quote Link to comment Share on other sites More sharing options...
Cougar Posted April 17, 2011 Share Posted April 17, 2011 Try spraying some starter fluid into the intake to see if that will help the engine fire up. If it does then you know you have a fuel delivery problem. If that doesn't work then check the ignition system for a problem. Quote Link to comment Share on other sites More sharing options...
Manarius Posted April 17, 2011 Share Posted April 17, 2011 What you describe is exactly what a malfunctioning MAF sensor causes. Quote Link to comment Share on other sites More sharing options...
Durania Posted April 17, 2011 Share Posted April 17, 2011 What you describe is exactly what a malfunctioning MAF sensor causes. I agree as well. Quote Link to comment Share on other sites More sharing options...
Cougar Posted April 17, 2011 Share Posted April 17, 2011 (edited) If it is a bad MAF sensor causing the trouble shouldn't disconnecting the electrical connection to it allow the engine to start up? I seem to recall others using that trick in the past. Edited April 17, 2011 by Cougar Quote Link to comment Share on other sites More sharing options...
Manarius Posted April 17, 2011 Share Posted April 17, 2011 If it is a bad MAF sensor causing the trouble shouldn't disconnecting the electrical connection to it allow the engine to start up? I seem to recall others using that trick in the past.That's what the book says. The car is supposed to use pre-programmed a/f settings, but in my experience that doesn't work. If you remove the MAF, the car just flat out won't start. When my MAF was busted, the car would just shut off randomly, not run for very long, and then eventually not even start. If the TPS was busted, the car would probably just run pretty poorly. Quote Link to comment Share on other sites More sharing options...
1-3-2-4 Posted April 17, 2011 Share Posted April 17, 2011 That's what the book says. The car is supposed to use pre-programmed a/f settings, but in my experience that doesn't work. If you remove the MAF, the car just flat out won't start. When my MAF was busted, the car would just shut off randomly, not run for very long, and then eventually not even start. If the TPS was busted, the car would probably just run pretty poorly. Is that for the 2nd gens too? I ran my car without the MAF plugged in and while it ran the A/F ratio was nuts first time I've never seen the temp gauge climb higher then at normal operating temps. It never flat out died or anything. Quote Link to comment Share on other sites More sharing options...
Manarius Posted April 17, 2011 Share Posted April 17, 2011 Is that for the 2nd gens too? I ran my car without the MAF plugged in and while it ran the A/F ratio was nuts first time I've never seen the temp gauge climb higher then at normal operating temps. It never flat out died or anything. TPS = Throttle Position Sensor Quote Link to comment Share on other sites More sharing options...
1-3-2-4 Posted April 17, 2011 Share Posted April 17, 2011 TPS = Throttle Position Sensor yeah I know what it stands for I was just wondering because it seems like some cars ran without them plugged and some died not too long after starting without them connected. Quote Link to comment Share on other sites More sharing options...
81subaruglguy Posted April 17, 2011 Author Share Posted April 17, 2011 well just found out that when i hot wire it the fuel pump only works when im cranking the motor. so were thinking thats the problem but still not sure Quote Link to comment Share on other sites More sharing options...
Cougar Posted April 17, 2011 Share Posted April 17, 2011 Can you hear the pump run briefly when you turn the key from OFF to ON? Another thing in case you aren't aware of it. If the ignition system isn't working then fuel pump circuit is shut down when the ignition system is set to the ON or RUN mode. Quote Link to comment Share on other sites More sharing options...
gbianchi Posted April 18, 2011 Share Posted April 18, 2011 crank angle sensor, cam sensor, knock sensor, just some ideas..........G Quote Link to comment Share on other sites More sharing options...
81subaruglguy Posted April 18, 2011 Author Share Posted April 18, 2011 ya but we dont want to start throwing sensors at it not knowing if it even needs them. wish there was a way to read the codes so we new what it really needs Quote Link to comment Share on other sites More sharing options...
Durania Posted April 18, 2011 Share Posted April 18, 2011 http://www.surrealmirage.com/subaru/engine.html Quote Link to comment Share on other sites More sharing options...
81subaruglguy Posted April 26, 2011 Author Share Posted April 26, 2011 ok so we messed with it today and hooked up a electric fuel pump to see if that was the problem and kinda made a difference but still wouldnt run. pulled the plugs and check compression and 3 out of 4 had 120 the front right or front left from front of car had 25 to 30. put oil in the cylinder and got it up to 120. i know that a trick ppl use if the rings r bad but then tested spark and its very weak but but it all back together and tried it and got it to run for 15 20 seconds. anyone know what it could be. oh we pull the crank sensor out when doing spark test and had no spark when it was out but were lost still thinking it could be a fuel problem but we have to get this car done this week so please help me out Quote Link to comment Share on other sites More sharing options...
81subaruglguy Posted April 27, 2011 Author Share Posted April 27, 2011 what could be going on here? we have tell saturday to get this car running and smogged so every little bit of help would be great thanks Quote Link to comment Share on other sites More sharing options...
johnceggleston Posted April 27, 2011 Share Posted April 27, 2011 the crank sensor generates spark, the cam sensor generates fuel. pulling either will kill the related event. fuel pressure?? if it really ran better after messing with the fuel pump, maybe the fuel pressure regulator has a problem. passenger side front cylinder is the #1 . low compression does not sound good but one bad cylinder should not keep it from starting. 120 sounds a little low but since the 3 were the same it could just be the gauge or how you tested it. Quote Link to comment Share on other sites More sharing options...
81subaruglguy Posted April 27, 2011 Author Share Posted April 27, 2011 whats the fuel pressure suppose to be at ? Quote Link to comment Share on other sites More sharing options...
81subaruglguy Posted April 27, 2011 Author Share Posted April 27, 2011 and test what line cause there r a few there but need to know cause running out of time Quote Link to comment Share on other sites More sharing options...
81subaruglguy Posted April 28, 2011 Author Share Posted April 28, 2011 ok checked the fuel pressure and it pegs out the gauge only when cranking. acts like a mechanical pump instead of a electric pump. only thing we can think of is a bad pump and were going to by pass the relay and see if we can even hear it cause we cant hear it all all but with a electric pump hooked up and we crank it over 30 times we get 5 gallons of gas from the tank and only cranking for 5 to 10 seconds at a time. so could it be a wiring problem or could it be the pump is bad and is working like a mechanical pump. this is that last things we can think of Quote Link to comment Share on other sites More sharing options...
81subaruglguy Posted April 28, 2011 Author Share Posted April 28, 2011 ok well the fuel pump is no good was able to find the plug for it and test it and nothing. so now trying to drop the tank and having the hardest time trying because the front one i cant get too cause there is a bracket in my way and have to undo the hole rear end of the car to get to the bolt or unless i mess up a tool to get up in there. anyone have any ideas? need to know like today Quote Link to comment Share on other sites More sharing options...
Olnick Posted April 28, 2011 Share Posted April 28, 2011 You don't need to drop the tank IIRC. Remove the cover plate under the rear seat and remove the pump from the top. Quote Link to comment Share on other sites More sharing options...
81subaruglguy Posted April 28, 2011 Author Share Posted April 28, 2011 we dont see a cover plate at all so were is it Quote Link to comment Share on other sites More sharing options...
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