Multisurface-Legacy Posted March 29, 2018 Share Posted March 29, 2018 (edited) 1999 Subaru Legacy 30th anniversary edition 5 speed MT ej22 Car starts, runs for a few seconds, then dies, will not idle. With proper TPS adjustments car runs without MAF connected, but dies as soon as it's plugged in. Car ran perfectly healthy until I replaced coolant temp sensor, tried putting old sensor back in, did not help. Tried pumping gas while starting car, caused motor to sputter,buck and die. Whats new: MAF (has been replaced three times over the course of two weeks) TPS PCV valve Hoses that connect to the PCV from the torque box Battery Thermostat Coolant temp sensor What's been tested: Fuel pressure within spec gets spark gets fuel All sensors have been back tasted and are receiving and putting out the proper amount of electricity. Smoke tested for vacuum leaks (there were none) I have absolutely no idea what could be wrong, after the extensive amounts of diagnosis I'm at a standstill. Any suggestions would be appreciated. Edited April 3, 2018 by Multisurface-Legacy 1 Quote Link to comment Share on other sites More sharing options...
Fairtax4me Posted March 30, 2018 Share Posted March 30, 2018 Has an air leak between the MAF and the throttle body. Did this start suddenly or after doing some work? Which "Proper" TPS adjustments? Anything except the factory setting is improper. TPS is critical for the ECU to determine idle speed and idle air fuel ratio. Quote Link to comment Share on other sites More sharing options...
keith3267 Posted March 31, 2018 Share Posted March 31, 2018 In addition to a possible air leak between the MAF and throttle body, you could have a bad intake manifold gasket or even a cracked intake manifold. Other possibilities include a vacuum hose disconnected, major break in a vacuum line, especially the one to the brake booster or a bad brake booster. But, I would first disconnect the battery overnight, or even for up to 24 hours, then reconnect everything and restart the engine. Give it a chance to learn the new MAF sensor. Quote Link to comment Share on other sites More sharing options...
Multisurface-Legacy Posted April 2, 2018 Author Share Posted April 2, 2018 Has an air leak between the MAF and the throttle body. Did this start suddenly or after doing some work? Which "Proper" TPS adjustments? Anything except the factory setting is improper. TPS is critical for the ECU to determine idle speed and idle air fuel ratio. "Proper" TPS adjustment means adjusting the new TPS to the factory setting. As can be read in the original post, I smoked the system to check for vacuum leaks, there are none. This began after changing the coolant temp sensor, I tried putting the old sensor back in, there was no change. Car still starts, but dies immediately. Quote Link to comment Share on other sites More sharing options...
Multisurface-Legacy Posted April 2, 2018 Author Share Posted April 2, 2018 In addition to a possible air leak between the MAF and throttle body, you could have a bad intake manifold gasket or even a cracked intake manifold. Other possibilities include a vacuum hose disconnected, major break in a vacuum line, especially the one to the brake booster or a bad brake booster. But, I would first disconnect the battery overnight, or even for up to 24 hours, then reconnect everything and restart the engine. Give it a chance to learn the new MAF sensor. I have disconnected and reconnected the battery in this manor at least ten times whilst trying to fix this problem, I smoked the system and discovered no vacuum leaks. Quote Link to comment Share on other sites More sharing options...
Gloyale Posted April 2, 2018 Share Posted April 2, 2018 99 legacy (with 2.2, not outback) has the weird double air box setup. I will bet that the second air box (long one) is probably not sealed tightly. It's often difficult to get the bottom tabs fully engaged and the whole unit tightly sealed. Take the box off and get it completely sealed, then install back onto the engine. $20 bucks say's that's yer problem. Quote Link to comment Share on other sites More sharing options...
Fairtax4me Posted April 3, 2018 Share Posted April 3, 2018 What Gloyale said or one of the hoses for the PCV/ breather tubes near the back corner of the bell housing might have broken or isn't connected properly. Quote Link to comment Share on other sites More sharing options...
Multisurface-Legacy Posted April 3, 2018 Author Share Posted April 3, 2018 What Gloyale said or one of the hoses for the PCV/ breather tubes near the back corner of the bell housing might have broken or isn't connected properly. I'm intrigued by Gloyale, will have to try that I replaced both the PCV and the y shaped configuration of hoses that connects to it. Quote Link to comment Share on other sites More sharing options...
Multisurface-Legacy Posted April 3, 2018 Author Share Posted April 3, 2018 99 legacy (with 2.2, not outback) has the weird double air box setup. I will bet that the second air box (long one) is probably not sealed tightly. It's often difficult to get the bottom tabs fully engaged and the whole unit tightly sealed. Take the box off and get it completely sealed, then install back onto the engine. $20 bucks say's that's yer problem. I have not tried this but it seems very plausible, would you recommend replacing the air filters? I know they have a rubber sort of setting around them, could that help the box seal? Any suggestions on what to seal it with? I don't recall there being a gasket. Quote Link to comment Share on other sites More sharing options...
lmdew Posted April 4, 2018 Share Posted April 4, 2018 The filters seals up the air box pretty good. I have replaced the newer style double airbox with the older 90-95 intake tube. It works well on the 2.2 swaps. Quote Link to comment Share on other sites More sharing options...
Gloyale Posted April 4, 2018 Share Posted April 4, 2018 I have not tried this but it seems very plausible, would you recommend replacing the air filters? I know they have a rubber sort of setting around them, could that help the box seal? Any suggestions on what to seal it with? I don't recall there being a gasket. no gasket. Just a good air filter should work. Quote Link to comment Share on other sites More sharing options...
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