SoobDood05 Posted May 29, 2015 Share Posted May 29, 2015 (edited) So after having my fuel tank boiled and cleaned of rust. i blew out all the fuel lines and soaked the injectors in cleaner. got it all put back together with the modified fuel rail to fit the adjustable fuel pressure regulator. i actually had the car running very well with no issues with the fuel pressure set correctly. then all of the sudden the car would not start again with the original flooding issue. if it does start you have to have the throttle wide open and it bareley will start at that and misfire badly. and if you let it die it will not restart. but if you shut of the key it will restart. when i block off the return line i cannot see any noticeable pressure loss so that tells me the injectors are not leaking. im wondering if my issue is with the pcm. i had it running perfect and it just shut off and wouldnt start suddenly. if the pcm is opening the injectors to much or holding them open too long then i think it would definatley cause this. i have no codes. some times when i turn the key over the oxygen monitor light flashes rapidly and sometimes wont kick on the fuel pump until i give the pcm a tap. unless its just coincidental i dont know. when the car does run without missing, it runs perfect with no issues. then all the sudden it has a terrible misfire/and flooding. so if anyone who has input please help me out. i will be testing the resistance of each injector and circuit. injectors for proper power supply, and ground drive circuits and other pcm crap. Edited May 29, 2015 by SoobDood05 1 Link to comment Share on other sites More sharing options...
SoobDood05 Posted June 21, 2015 Author Share Posted June 21, 2015 So when testing the injector circuits the readings seem to fluctuate a lot. But I have source voltage on the control side of the injector circuit and the test connector side. So good. When testing from each injector on the check connector to the positive battery cable at first I got an excessive resistance reading of 5+ ohms on each one. Then the last time I got between 2-3 ohms which is within spec. At first from check connector ground to body ground I had lots of resistance. Then after a few hours i checked again and it went back down to 0-0.1 ohms. Within spec. But when I check the resistance from each injector on the check connector to the ground driving circuit for the injectors now I am getting between 3-0.556 mega ohms. Which I didnt before. Keep in mind this car runs. But has a steady miss under all conditions. No codes. And if you unplug the injectors they all make a noticeable difference. Any input from you subaru gurus would be awesome. Most of my tests are leaning toward pcm replacement. But I dont want to condemn it just yet. Link to comment Share on other sites More sharing options...
Dinky26 Posted June 21, 2015 Share Posted June 21, 2015 What model and year are dealing with, manual or auto, 2wd or 4? Link to comment Share on other sites More sharing options...
turbosubarubrat Posted June 21, 2015 Share Posted June 21, 2015 (edited) What model and year are dealing with, manual or auto, 2wd or 4? ea81t's were made from 83-84 and only came with a 4wd 3at from factory. I kind of had the same problem with ea81t wagon luckily i had a good ecm that came as a spare in another ea81t wagon i had. The fuel system did weird things with that ecm injectors wouldn't turn on sometimes, fuel pump would run sometimes, and other times it startup just fine. With the ecm the other ecm it ran great and didn't have any problems. If worse came to worse you could wire in a mega squirt system. Edited June 21, 2015 by turbosubarubrat Link to comment Share on other sites More sharing options...
SoobDood05 Posted June 21, 2015 Author Share Posted June 21, 2015 Its an 84 2dr coupe 3at all original besides the adjustable fpr ive installed. I'm trying to source a new pcm at the moment. Link to comment Share on other sites More sharing options...
naru Posted June 21, 2015 Share Posted June 21, 2015 (edited) So when testing the injector circuits the readings seem to fluctuate a lot. But I have source voltage on the control side of the injector circuit and the test connector side. So good. When testing from each injector on the check connector to the positive battery cable at first I got an excessive resistance reading of 5+ ohms on each one. Then the last time I got between 2-3 ohms which is within spec. At first from check connector ground to body ground I had lots of resistance. Then after a few hours i checked again and it went back down to 0-0.1 ohms. Within spec. But when I check the resistance from each injector on the check connector to the ground driving circuit for the injectors now I am getting between 3-0.556 mega ohms. Which I didnt before. Keep in mind this car runs. But has a steady miss under all conditions. No codes. And if you unplug the injectors they all make a noticeable difference. Any input from you subaru gurus would be awesome. Most of my tests are leaning toward pcm replacement. But I dont want to condemn it just yet. You have a bad ground. Tighten/clean the connection or run a new wire. Check the ground on Check Connector I as well. Measure resistance between body ground and battery negative too. I`m not sure how you are taking the second measurement. You cannot measure resistance between the injectors and ground(ecu semiconductors are in the way) Maybe more than one problem. The ECU should not respond to taps. The fuel pump driver transistor has failed in mine.I use alternate power. Edited June 21, 2015 by naru Link to comment Share on other sites More sharing options...
SoobDood05 Posted June 21, 2015 Author Share Posted June 21, 2015 (edited) Ive been taking all the readings with the ecu connectors unplugged. An ifdy ground is what I have been suspecting. But I'm not sure where this one is. The second reading I'm taking is from the check connector side of the injectors through them and to battery positive cable while disconnected. I used battery negative to check the ground too and a few times it was high resistance. Then another time there was barely any. The ground for the injector drive circuit is shared by the fuel pump relay/fuel pump. And the ignition relay. Ive had the pump not kick on before until I messed with a few things and tapped the ecu. Coincidence? And a few times id turn the key and it wouldnt crank. So I think the ground is a good suspect. Now just to find where its located. Edited June 21, 2015 by SoobDood05 1 Link to comment Share on other sites More sharing options...
naru Posted June 21, 2015 Share Posted June 21, 2015 Check connector IV to battery positive should only be injector resistance,not megaohms. There is a bad connection at one of the wiring harness plugs/bad fusible link/poor connection from battery positive to the fusible link etc. Variable ground resistance suggests a poor connection at a plug too, Like I mentioned previously,body ground is above the fusebox(remove it) A poor connection to the fusible link box could give cranking problems. Link to comment Share on other sites More sharing options...
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