Knichol Posted August 15, 2005 Share Posted August 15, 2005 I have a 1996 2.2L that is having some idle issues. Symptoms: once motor gets relatively warmed up the Idle starts to pulse form about 800 to 1300 back down to 800 at a beat of about once every 8 seconds. There are no MIL's (engine check light errors) current or pending when I check it with an obdII reader/scanner. Any suggestions on what it might be? Quote Link to comment Share on other sites More sharing options...
Sweden Posted August 15, 2005 Share Posted August 15, 2005 I'm no expert but I had the same problem with my 1996 2.2. See the thread 'new alternator/uneven idle' for some ideas; I posted today so its around here. There was everything from the temp sender to O2 sensor. My problem was the wrong alternator. Good luck! Sweden Quote Link to comment Share on other sites More sharing options...
Knichol Posted August 16, 2005 Author Share Posted August 16, 2005 OK, I had two extra alternator's, and I believe all three are good, I tried them all and still no change with the changing idle, Vacuum lines are good, and the temp sensors are still reading where they should, including the one that goes to the ecu. Change O2 sensors front and rear and still no change. Any Other Suggestions? I will resort to doing a magical Subaru dance if anyone knows the moves! Quote Link to comment Share on other sites More sharing options...
Legacy777 Posted August 16, 2005 Share Posted August 16, 2005 possibly the idle air control valve. May also want to look at the EGR valve. Quote Link to comment Share on other sites More sharing options...
Knichol Posted August 16, 2005 Author Share Posted August 16, 2005 possibly the idle air control valve. May also want to look at the EGR valve. I played around with the idle air control valve with no change. I will check the fsm to see what the spes should be or replace it completely. If I increase the idle to about 1100 the changing idle disappears. I will check the EGR to make sure that its not plugged and is working correctly. I heard rumor that Subaru stopped putting egr valves on after a certain year is that true? Thanks for your suggestions, if you come up with any more please let me know. Quote Link to comment Share on other sites More sharing options...
frag Posted August 16, 2005 Share Posted August 16, 2005 OK, I had two extra alternator's, and I believe all three are good, I tried them all and still no change with the changing idle, Vacuum lines are good, and the temp sensors are still reading where they should, including the one that goes to the ecu. Change O2 sensors front and rear and still no change.Any Other Suggestions? I will resort to doing a magical Subaru dance if anyone knows the moves! Underlined passage : do you mean you tested the resistance accross the connector of the ECU Temp sensor and if so how did you do it? Quote Link to comment Share on other sites More sharing options...
Knichol Posted August 16, 2005 Author Share Posted August 16, 2005 Underlined passage : do you mean you tested the resistance accross the connector of the ECU Temp sensor and if so how did you do it? To check the ECU temp sensor reading I looked at what its output temp was via an obdII scanner/software and then checked it to the temp of digital output on the guage sensor. They both read the same temp. I was going to follow it up by checking what the the resistance range should be and make sure its within that range. Quote Link to comment Share on other sites More sharing options...
frag Posted August 16, 2005 Share Posted August 16, 2005 To check the ECU temp sensor reading I looked at what its output temp was via an obdII scanner/software and then checked it to the temp of digital output on the guage sensor. They both read the same temp. I was going to follow it up by checking what the the resistance range should be and make sure its within that range. Did you do that during the bouncing idle episode? If the temps sensor is the culprit (I had similar symptoms on a Loyale that were coolant temp sensor related) you should see the temp readings also bouncing at that moment. If not you can rule out the temps sensor. Sorry if maybe giving advice too obvious. Just trying to help. Good luck! Quote Link to comment Share on other sites More sharing options...
Knichol Posted August 16, 2005 Author Share Posted August 16, 2005 No your advice is awesome! There has been more than once where I was sure I had ruled something out and it ended up coming back and getting me in the butt. I was checking while the idle was irregular and the temps stayed the same/rising slightly. The only flux in temp was when the fan turned on which made the temp drop until the fan turned off. Thanks once again for all your help and effort! Anything else you might suggest please do so! Quote Link to comment Share on other sites More sharing options...
1 Lucky Texan Posted August 16, 2005 Share Posted August 16, 2005 I guess the A/C and defrost modes are off when this happens? Carl Quote Link to comment Share on other sites More sharing options...
Knichol Posted August 16, 2005 Author Share Posted August 16, 2005 I guess the A/C and defrost modes are off when this happens? Carl Yes, the idle pulse happens reguardless of AC/Defrost/fan/lights. I say this only because I have driven it around at night and day with all on and all off and almost every combination between. What effects would the A/C and Defrost have if they were mal-funtioning? Quote Link to comment Share on other sites More sharing options...
1 Lucky Texan Posted August 16, 2005 Share Posted August 16, 2005 Yes, the idle pulse happens reguardless of AC/Defrost/fan/lights. I say this only because I have driven it around at night and day with all on and all off and almost every combination between. What effects would the A/C and Defrost have if they were mal-funtioning? Oh well, I was just wondering if the A/C compressor kicking on and off was possibly invovled - but you would likely have heard/seen that looking under the hood or otherwise. It seems not to be part of the problem though. 8 seconds is pretty fast - but I'll ask anyway, is it in synch with the rad cooling fan cycling on and off? Carl Quote Link to comment Share on other sites More sharing options...
Knichol Posted August 16, 2005 Author Share Posted August 16, 2005 Oh well, I was just wondering if the A/C compressor kicking on and off was possibly invovled - but you would likely have heard/seen that looking under the hood or otherwise. It seems not to be part of the problem though.8 seconds is pretty fast - but I'll ask anyway, is it in synch with the rad cooling fan cycling on and off? Carl No the fan turns on for about 1min and a half and then shuts off for about 30 seconds. (These are just guesses) The idle stays at about 800 jumps to about 1200 and then comes down to 800 for a two or three, then bounces again. the whole idle process takes about 8 seconds. The idle starts to bouce once it has ran for about 45 seconds, at which time the water temp is around 149 f. Thanks once again for your time and effort in helping with my problem Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.