idosubaru Posted April 5, 2006 Share Posted April 5, 2006 i have a non-turbo XT that won't start. three different ECU's, one won't run the fuel pump, the other two no spark. no codes. my intake/vaccuum set up is marginal at best. can the intake/vaccumm lines cause a no start or no- spark condition? the purge control solenoid and AAV, anyone know if they can cause these problems if they aren't hooked up right? i get the same thing if they are plugged in or not. pretty sure the vacuum connections to them might be incorrect. if anyone can tell me where the input/output to these is routed that would be great. Link to comment Share on other sites More sharing options...
Loyale 2.7 Turbo Posted April 5, 2006 Share Posted April 5, 2006 Well... I really think that bad connections on Vacuum lines can´t make any engine to unstart, due to the fact that vacuum only exist with a running engine. But in the other hand, bad connections on electrical cables can do that. I sugest to: First: Check the main electrical Lines. The ones flowin´ from the Battery. Also a Rusty Fuses Links can do that too. Check for burnt / Corroed Fuses. False contact in any main cable. Also, if you wanna put all your vacuum lines in correct order, I think that is a Good Idea to send us a Image of those lines actually config. to tell wich ones are exactly the bad connected ones. Good Luck! Link to comment Share on other sites More sharing options...
idosubaru Posted April 5, 2006 Author Share Posted April 5, 2006 the XT6 ECU starts and runs the car fine in first and second gear so i think the connections, power and fuses are all fine. but who knows at this point??? i like the idea of posting pictures. i'll snap some pics of my current vacuum hose routing and of the AAV and purge control solenoid and see. these shouldn't interfere with creating spark, so i agree with what you're saying about them not affecting starting. thanks for keeping me straight...i'm starting to loose track of where i need to go from here. Link to comment Share on other sites More sharing options...
Subarian Posted April 5, 2006 Share Posted April 5, 2006 Gary, You mentioned one of your ECUs won't run the fuel pump. It might not be helpful to you, but I run the fuel pump on my carbed wagon directly off the + terminal on the coil. You might want to try a jumper and see if that will get it running. Link to comment Share on other sites More sharing options...
idosubaru Posted April 5, 2006 Author Share Posted April 5, 2006 You mentioned one of your ECUs won't run the fuel pump. It might not be helpful to you, but I run the fuel pump on my carbed wagon directly off the + terminal on the coil. You might want to try a jumper and see if that will get it running. on man, don't suggest this. i did this and the car ran GREAT with that ECU. except it wouldn't idle. i wired the fuel pump directly alright with a switch in my center console. a couple days later i was near death when the interior carpet caught fire, filled the cabin with smoke and i'm trying to figure out which position is on/off on the switch....bad news that was. finally smarted up and drifted it back into the field away from my house and barn!!! ripped the wires out by hand and dumped water everywhere. no fire. i drew up a wiring system with a fuse and relay which im' going to put together tonight. trying to think of a good option for switching the relay....you say the ignition coil? should i put the fuse on the POSITIVE battery cable and the relay on the Negative ground wire of the fuel pump? i figured on doing this, then trying to figure out the idle.....then go from there. all the details are confusing the CRAP out of me....some ECU's only fuel no spark. some spark and no fuel...and the 4 cylinder car only runs on a 6 cylinder ECU....i don't even know what tail to chase anymore. i'm going to persure the fuel pump hard wire again, that will at least get the car driveable for now until i can get some ECU's tested. i'll search for some wiring info, i'm not a wiring expert and want to make sure i do this right. Link to comment Share on other sites More sharing options...
Subarian Posted April 5, 2006 Share Posted April 5, 2006 Unless I'm mistaken, the negative post on the coil grounds through the distributor, so it might cause some issues with your relay. The positive post is always hot when the ignition is on, which is why I chose that one. I haven't experienced any problems with it and I've used it like that for about 50,000 miles. Link to comment Share on other sites More sharing options...
idosubaru Posted April 5, 2006 Author Share Posted April 5, 2006 Unless I'm mistaken, the negative post on the coil grounds through the distributor, so it might cause some issues with your relay. The positive post is always hot when the ignition is on, which is why I chose that one. I haven't experienced any problems with it and I've used it like that for about 50,000 miles. cool thanks! i'll test it for kicks with the meter and then wire the positive terminal to the relay. did you wire it with no relays or fuses in place? i'm too scared too now, but wondering if you did it. Link to comment Share on other sites More sharing options...
Subarian Posted April 5, 2006 Share Posted April 5, 2006 It's fused, but no relay. Link to comment Share on other sites More sharing options...
Dylan86GL10 Posted April 5, 2006 Share Posted April 5, 2006 Gary, Things I would check, it seems that one at least some ECU's, the ECU supplies not only the fuel pump relay trigger (ground) but also the pump ground. If you check out the wiring diagram you'll see what I mean. Also there are a number of switches in the harness that could impact starting. Not sure what you have setup in the harness as far as the boost switch? I think the later cars got rid of the overboost switch and incorporated into the MAF so that probably doesn't apply to you. I would start with ensuring that the fuel pump kicks on, on any of the ECUs that appear to not be working. If not ground both the relay and the (-) on the pump. If you have a big enough Vac leak on a MAF car it won't start as it will be running much leaner than it should. This is a dumb question but is the turbo MAF and MPFI MAF the same? Link to comment Share on other sites More sharing options...
idosubaru Posted April 5, 2006 Author Share Posted April 5, 2006 thanks for the suggestions, i'm beat on this one and the wife is telling me to just buy an impreza...NOOO!!!!! i'm too stubborn! the fuel pump relay clicks and the fuel pump cycles properly in diagnostic mode every 1.5 seconds and i have good fuel pressure at the engine. the motor runs with the XT6 ECu or with the one ECU and a hard wired fuel pump - so the fuel pressure regulator should be good i guess though i don' t know how that works. anyway....seems to me the fuel system is good...definitely smells like it's running way rich though, but maybe that's just the exhaust gasket leak at the converter. boost switch i think i left it connect...is this the same as the Waste Gate Solenoid? i have that connected but no lines connected to it since i has no turbo. someone told me that should be fine. i think i tried it unconnnected and no difference, but i'll try again. although maybe the boost pressure switch is difference, above the WGDS, i have the disconnected i think. it is a MAF sensor and the NA and turbo ones i have are identical in part number, but i'll double check that tonight. now...the vacuum lines i'm sure are ALL jacked up. i have the charcoal canister lines all exposed and only the 4WD switch getting vaccuum. mabye i'm missing one that should be connected to the purge solenoid or AAV, but i don't know where they go or are routed. if these can affect starting then that's my issue. but they start and idle on the XT6 ECU??? i'm getting tired of posting this...too much info and details, getting confused......head hurting....blurry vision.... Link to comment Share on other sites More sharing options...
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