zuki1100 Posted August 13, 2011 Share Posted August 13, 2011 I've read a lot of info here about people experiencing similar problems, however I haven't seen anyone mention an observation that I made...which leads me to believe I may have a unique problem??? About 2 months ago I was climbing a hill (4wding) and when I got to the top the idle was very rough. I was hitting WOT. From there it wouldn't idle at all and would stall. Drove home fine, the engine would run fine at cruising speed but when I came to stop it would idle rough and stall. Ran fine after that for a few weeks then did it again heading to work one day and didn't come right at all. So I swapped over my carb for one off an EA82 thinking that will fix the issue, but it didn't. Was out yesterday and found that the car runs fine if you DON'T give it full throttle. As soon as you go WOT, when you come to a stop immediately after the idle is rough and the engine eventually stalls. Have found in doing this if I engage the Air Con, this helps keep the revs up if it's threatening to stall...but only works sometimes as when it's about to stall (I assume) it's not generating enough vacuum to engage the AC idle up solenoid. So I'm quite sure this issue comes about right after going WOT. Something else to add...while out yesterday I went WOT, the idle went very low and would keep stalling every time I came to a stop, did this for 5 or so mins then while coming up to stop it did it again, I crash started it (using the engine to to restart while still moving) and the idle came back to normal. Cold starting is fine, electric choke works normally and well. Engine seems to idle fine after warm up. Sorry for the long wordy post...just trying to offer as much info as possible. Look forward to some idea's and advice on where to look. Link to comment Share on other sites More sharing options...
zuki1100 Posted August 14, 2011 Author Share Posted August 14, 2011 A little update, have replaced fuel filter this morning to at least eliminate that as a potential problem, only cost $5.00 and I cut the old one open, was very dirty and had bits of "stuff" in the bottom of it. Link to comment Share on other sites More sharing options...
Dirk Posted August 15, 2011 Share Posted August 15, 2011 Could be that the plugs are fouling at WOT. Seconardy too rich? or maybe a sticky power valve. When you swapped over the carbs did you swap over the jets? Link to comment Share on other sites More sharing options...
zuki1100 Posted August 15, 2011 Author Share Posted August 15, 2011 No, just swapped the carb directly over. I'm wanting to think it's not a carb issue as the problem happened on both carbs, surely the same issue wouldn't be evident on both carbs? Went out last night to get a bottle of wine, car ran fine. Stopped and got the wine, went back to the car, started and the idle was stumbling again, almost stalling but came right within 1-2mins of driving. I'm planning now to clean up all the valves and manifold of non-essential items, so remove the EGR, plug non essential vacuum lines and clean the PCV valve. Link to comment Share on other sites More sharing options...
phantomD Posted August 16, 2011 Share Posted August 16, 2011 I had this on an EA81...alternator/battery/charging system/other electrical. Link to comment Share on other sites More sharing options...
zuki1100 Posted August 16, 2011 Author Share Posted August 16, 2011 Cool, I'll check that out. Battery appears to be OK, but I suppose you never know. Have found also that if it goes into the stall situation while still moving like when slowing down for intersection and I release the clutch in gear to restart the motor, the rough idle is immediately gone and revs go back to normal. What do you suppose is happening when I start the car in this way that makes this problem go away? Link to comment Share on other sites More sharing options...
zuki1100 Posted August 26, 2011 Author Share Posted August 26, 2011 A bit more to this story... Have found the rough idle/stall usually occurs after the choke has disengaged, but will also happen during acceleration (not always WOT) and not all the time. Sometimes, however, WOT will also correct the problem and the idle will return to normal afterwards. So I'm perplexed as to what could be causing this...some thoughts... -Intermittent vacuum leak? -Intermittent problem with the carb idle circuit (although have tried two different carbs with the same problem...coincidence??) -Electrical problem? Battery shows 13.89V at idle which is about right for a normal charge. -Throttle linkage problem, not fully returning to fully closed position? At idle I have noticed a loudish sucking sound at the front of the carb where the power steering pump is. But the idle will be normal while this sound is there. Might try changing back to my original carb and see if the problem is worse/better. Very keen for some more thoughts from everyone out there and trouble shooting. Link to comment Share on other sites More sharing options...
Dirk Posted August 26, 2011 Share Posted August 26, 2011 I'm still thinking the plugs are fouling. Maybe due to weak spark. I would like to see the condition of the plugs. When did you last change them? Maybe check the igition system. Make sure you are getting a good spark. Plugs Points Cap Rotor Leads. You got a manual? Link to comment Share on other sites More sharing options...
zuki1100 Posted August 27, 2011 Author Share Posted August 27, 2011 I'm still thinking the plugs are fouling. Maybe due to weak spark. I would like to see the condition of the plugs. When did you last change them? Maybe check the igition system. Make sure you are getting a good spark. Plugs Points Cap Rotor Leads. You got a manual? Changed the plugs about 12 months ago, they are the NGK V-Groove type. Interesting you say that...the front plugs both sides are a brownish colour which suggests they are OK ad the the back plugs, both sides are black (carboned). It's an electronic distributor, how do I check this is functioning correctly? Any test/check I can do? Cleaned cap contacts, they are passable, can't get a replacement easily and a new one from Subaru is $150.00 and 1 week ex-Japan. Brand new Rotor put in 2 days ago. Leads are Bosch Super Sport from memory, they were new about 12 months ago, same time as plugs. Yes I have a manual. You think it's worth while changing out the plugs & leads for a spare set I have? I suppose it would be good comparison. Link to comment Share on other sites More sharing options...
Dirk Posted August 27, 2011 Share Posted August 27, 2011 Odd that only two plugs are fouled......... I would make a start on the dizzy. First up, is there any play in the shaft? Next, check the air gap between the paddle and the pickup. Should be 0.14" Be absolutely sure there are no cracks in the cap. Maybe you could borrow a cap from someone to try just to be sure. Cheers. Dirk. Link to comment Share on other sites More sharing options...
Dirk Posted August 27, 2011 Share Posted August 27, 2011 'You think it's worth while changing out the plugs & leads for a spare set I have? I suppose it would be good comparison.' Always worth a shot but better to change only one thing at a time. Link to comment Share on other sites More sharing options...
zuki1100 Posted August 31, 2011 Author Share Posted August 31, 2011 Have adjusted the air/fuel mixture screw for a mid setting between what I assume is too rich and too lean...I realise this is a bit of a black art to get right without proper equipment and going just by ear. Also swapped over the coil to distributor HT lead and the two rear cylinder leads that were running black plugs. At this stage, run to work and home it stalled once and that was in the morning on the way to work when the choke had opened up and the engine was still quite cold. Seemed to idle around 600-700rpm this morning and about 800rpm on the way home. With a bit of WOT the idle improved, up to 900-1000rpm for a period of time. I'm going to try making the mixture a bit richer and see if that improves the idle and also adjust the choke to stay on a bit longer. Will update again once I've done a few runs to work and back Link to comment Share on other sites More sharing options...
Dirk Posted August 31, 2011 Share Posted August 31, 2011 (edited) Sounds like you are about right with the idle mixture screw but remeber a few things. Firstly, that it is just an idle mixture screw. it only affects idle and just off idle. Secondly, if the plugs are fouling up then if anything something could be too rich already. Thirdly, Anything you do to the carb will be affecting all four cylinders. Since you have narrowed the problem down to two cylinders it would suggest that it is not a carb related problem. I think you should be looking more closely at the igition system. Since timing will affect all four cylinders it is unlikely to be timing related. Did you check the condition of the distributor already? Also clean up those plugs and reset the gaps. My primary suspect would be a cracked distibutor cap or perhaps some moisture in there. Maybe leave the choke alone for now untill you have eliminated all other variables Edited August 31, 2011 by Dirk Link to comment Share on other sites More sharing options...
zuki1100 Posted September 25, 2011 Author Share Posted September 25, 2011 Have still not had any luck resolving this issue...but...I think I have made a minor break through. As previously mentioned #1 & #2 plugs (both front) appear normal colour & condition. #3 & #4 plugs are both carbon fouled very badly. Tried replacing the entire distributor and problem is still there so I feel safe to assume it's not an issue with that. Replaced coil back to standard from the Accel Super Stock one I did have...still have the problem. Today I swapped the plug leads over. I did have Bosch Super Sport Inductive Coil type fitted (only 6 months old) and put in an old set from an EA82. I then pulled the plugs out for a check and #3 & #4 plugs have cleaned up nicely to the normal colour after a very short test drive. Could all this problem be from the plug leads??? I will feel very STUPID if I find it's lead related (being such an easy fix) and for some reason my ignition system doesn't like the Bosch Super Sport type. Anyone else reading this had issues with Bosch Super Sport Inductive Core HT Leads?? I'll now be trying a standard set of leads and see what happens... Link to comment Share on other sites More sharing options...
Loyale 2.7 Turbo Posted September 25, 2011 Share Posted September 25, 2011 ...some thoughts...-Intermittent vacuum leak?... I believe that your subie's engine has an intermitent Vacuum Leak, So I Kindly Suggest you to Check the entire intake Manyfold for small Cracks, and / or worn seals. Kind Regards. Link to comment Share on other sites More sharing options...
Recommended Posts
Please sign in to comment
You will be able to leave a comment after signing in
Sign In Now