d-jet a.a.r. question, 8/18/ AAR open vs closed - effect on setting timing-advance |
|
Porsche, and the Porsche crest are registered trademarks of Dr. Ing. h.c. F. Porsche AG.
This site is not affiliated with Porsche in any way. Its only purpose is to provide an online forum for car enthusiasts. All other trademarks are property of their respective owners. |
|
d-jet a.a.r. question, 8/18/ AAR open vs closed - effect on setting timing-advance |
DRPHIL914 |
Aug 10 2011, 08:50 PM
Post
#1
|
Dr. Phil Group: Members Posts: 5,769 Joined: 9-December 09 From: Bluffton, SC Member No.: 11,106 Region Association: South East States |
I e tested 4 now and after 10 min none of them close completely or at all. Either way could it be because of a bad connection? Not hot enough? I know atleast one, the newest one was tested as good and is very clean. I know they can go bad inside but I do not think they all are.
But after 10 min of car at idle its still pulling air thru, suggestions please. Phil |
DRPHIL914 |
Aug 18 2011, 06:13 AM
Post
#2
|
Dr. Phil Group: Members Posts: 5,769 Joined: 9-December 09 From: Bluffton, SC Member No.: 11,106 Region Association: South East States |
I had a thought on this, wondering if this makes sense.
If when i last set the timing the aar was partially open, would this not have caused the distributor to be placed different to compensate for the effect of the AAR, so now if i close off the AAR it almost kills it, and even if the idle screw is out its not there, and so i was thinking that maybe timing might not be where it should be, if i advance the distributor slightly this should bring that idle up a little with the AAR plugged(as if it were closed- when hot)- like it should be. right now after running it 20 min last night idle was at 1100- 1250 while hunting and is running great down the road, and i could live with that - but i know its not right- with the a.a.r. half open it seems this is the best i can do - unless i can get a spare MPS to test(043). PW |
scott_in_nh |
Aug 18 2011, 06:24 AM
Post
#3
|
Senior Member Group: Members Posts: 808 Joined: 10-December 10 From: Hampton, NH Member No.: 12,471 Region Association: North East States |
I had a thought on this, wondering if this makes sense. If when i last set the timing the aar was partially open, would this not have caused the distributor to be placed different to compensate for the effect of the AAR, so now if i close off the AAR it almost kills it, and even if the idle screw is out its not there, and so i was thinking that maybe timing might not be where it should be, if i advance the distributor slightly this should bring that idle up a little with the AAR plugged(as if it were closed- when hot)- like it should be. right now after running it 20 min last night idle was at 1100- 1250 while hunting and is running great down the road, and i could live with that - but i know its not right- with the a.a.r. half open it seems this is the best i can do - unless i can get a spare MPS to test(043). PW Hi Phil, The timing is a mechanical setting indepedent of the issues we have here, but do check it. So it is still surging indicating a lean condition? Does adjusting the idle mixture on the ECU have any effect (even if it isn't the desired one)? No part throttle surging down the road? Considering that most all failures, even vacuum leaks, default to rich condition and because I know you already replaced FI points and most everything else, I think we are still looking at a MPS setting that your engine is not happy with. |
Lo-Fi Version | Time is now: 17th June 2024 - 10:38 AM |
All rights reserved 914World.com © since 2002 |
914World.com is the fastest growing online 914 community! We have it all, classifieds, events, forums, vendors, parts, autocross, racing, technical articles, events calendar, newsletter, restoration, gallery, archives, history and more for your Porsche 914 ... |