ICV? Maybe? try taking a pair of needle nose and crimp the hose and see if the idle comes down.....
Pirate air leak (Arrgggggg)
- Thread starter 7thousandpiecesMGTE
- Start date
Scot;1640438 said:
Plugged all ports to the intake manifold including the ISCV and the motor still runs, it should die with no air supply but it still runs at about 600-700 rpms. I need to check the tb plate to further narrow the air leak but its dark and raining right now. I will check it tomorrow.
Check the vacuum lines for the wastegate, fpr, and EGR. If one of those isn't hooked up, it'll idle high.
GrimJack;1640459 said:
External wastegate is currently only actuated by pressure line from turbo overcoming a 6psi spring, no boost controller hooked up and no vaccum line to it so thats out. FPR and EGR lines are all in good condition and connected properly.
Pirate air will not cause idle speed increase on an L Type engine. If it's induction leak related it has to be due to metered air.
jetjock;1640553 said:
Ah great... then I likely have another issue to sort out. Something else causing the high idle (could the afm be a suspect? I do have a code 31... ) AND a pirate air leak as confirmed by doing what Jdub says in post# 14 of this thread:
http://www.supramania.com/forums/sh...ed-help/page2&highlight=pirate+leak+high+idle
I plugged every stinking orifice on the intake manifold and the motor runs at 600-700 rpm. The motor is getting air from a leak somewhere between TB inlet and the cylinder head and I need to fix that issue as well. Unless its sucking air past the rings or through the MHG, God I hope not. it doesnt over heat, no white smoke no milkshake in the overflow. The motor hasnt run for very long maybe its possible the rings arent seated just yet (I did the reccommended break in procedure but it still has less than 50 miles on it. Guess I should do a compression check as well.... sigh. My vacuum at 1100 rpms sits steady at 14inhg, at that rpm level does that make sense, or is that a dumb question?
I am going to check the throttle plate, as previously suggested, tomorrow. If its good then I will remove the TB and ISCV inspect the gaskets put them back on and see if that fixes it. After that I will have to take the intake manifold off and check all of that.
Is there a better course of action that could be recommended?
Thanks for everyone's input I do appreciate your time and thoughts.
Pirate air only causes high idle on D Type (pressure metered) systems. On L Type (airflow metered) engines idle quality is effected. Assuming it's induction related L Type high idle has to involve metered air.
Throttle plate not fully closed or some issue related to TB bypass air eg; ISC path or power steering idle up. Note all of these "leaks" involve metered air. All pirate induction air on an L Type does is cause leanness, which is responsible for deterioration in idle quality, not speed.
It does sound like you have a leak. Just that the leak won't cause high idle. A bad AFM could sure do it though. Besides, there's little point in doing anything else until you get rid of the 31.
Throttle plate not fully closed or some issue related to TB bypass air eg; ISC path or power steering idle up. Note all of these "leaks" involve metered air. All pirate induction air on an L Type does is cause leanness, which is responsible for deterioration in idle quality, not speed.
It does sound like you have a leak. Just that the leak won't cause high idle. A bad AFM could sure do it though. Besides, there's little point in doing anything else until you get rid of the 31.
Understood. I will tackle the code 31 then get back to the leak. Thanks!
EDIT: You don't have to explain if you dont want to but I am curious as to why the two engine types react differently.... I may be getting a little above my head here but I'd like to learn....
I understand the AFM never sees the pirate air but wont the o2 sensor pickup the lean condition and then the ecu try to compensate with more fuel? does this late reaction cause the loping type idle?
With the map based system the ecu will see a difference of the pressure if the manifold right? But then would the ECU on this engine add more fuel before it combusts lean and therefore never be picked up by the o2 sensor as actually being lean and just cuases a higher idle?
EDIT: You don't have to explain if you dont want to but I am curious as to why the two engine types react differently.... I may be getting a little above my head here but I'd like to learn....
I understand the AFM never sees the pirate air but wont the o2 sensor pickup the lean condition and then the ecu try to compensate with more fuel? does this late reaction cause the loping type idle?
With the map based system the ecu will see a difference of the pressure if the manifold right? But then would the ECU on this engine add more fuel before it combusts lean and therefore never be picked up by the o2 sensor as actually being lean and just cuases a higher idle?
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jetjock;1640553 said:
Damn... I feel a little dumber today. In my defense, it's been a long time since I've run anything but MAP. Let the beatings commence...
You should feel a little smarter Dave. To feel dumber means I've failed
You're right about an idle increase when the FPR hose is disconnected though. However that's due to enrichment, not pirate air...
You're right about an idle increase when the FPR hose is disconnected though. However that's due to enrichment, not pirate air...
lol - no, I feel dumber because I *forgot*. Your reminder just made me better educated.
I know the differences between AFM / MAF / MAP type systems - hell, I've been one of the primary educators here, and if I'd been thinking scientifically, like I've been trained to do, instead of walking around in a stupor, I'd have realized the obvious. Anyway... back to our regularly scheduled thread.
I know the differences between AFM / MAF / MAP type systems - hell, I've been one of the primary educators here, and if I'd been thinking scientifically, like I've been trained to do, instead of walking around in a stupor, I'd have realized the obvious. Anyway... back to our regularly scheduled thread.
Are you absolutely sure about the linkage? My stepson's GE, had a high idle, and it finally turned out to be the adjustable rod in the linkage. The locknut was stripped, and vibration caused it to rotate, changing the length of the rod, and forcing the throttle plate open. Drove me crazy trying to find it.
rayall01;1640775 said:
100%. I can disconnect the metal rod and it makes no difference. There is actually slack in the throttle cable itself. But I do need to check the actual tb blade itself.
Just tested the AFM per tsrm and it failed miserably... e1 to ks is open, ks to e1 is open, vc to e1 is open and e1 to vc is open. only thing that passed was ks to e1 being open and THA to e2 was at 3k ohms which is normal for 70 degrees f. Gonna source one locally, replace it and then hunt down the pirate. I'll report back with my findings.
I thought with a bad afm the engine would only rev to 2000rpms? It ran pretty well for having a bad afm....
I thought with a bad afm the engine would only rev to 2000rpms? It ran pretty well for having a bad afm....
At the risk of failing again I guess you never saw the video I made a couple years back where I drive around town with everything upstream of the turbo removed
jetjock;1641012 said:At the risk of failing again I guess you never saw the video I made a couple years back where I drive around town with everything upstream of the turbo removed
LOL I have not seen this myself....
Update!
I looked at the throttle stop screw.... its set to far and I think its causing the tb blade to be open slightly. The bracket has a little give and when I pushed down the rpms lowered. It was getting dark so I didnt get to correct it yet and see if it drops to 650rpms but I think I found my leak.... this would explain just about everything: low vacuum reading, motor not dying when all orifices were plugged, and most importantly high idle.
If this does fix it then I have to change the (not so) clever title to this thread DOH!
I looked at the throttle stop screw.... its set to far and I think its causing the tb blade to be open slightly. The bracket has a little give and when I pushed down the rpms lowered. It was getting dark so I didnt get to correct it yet and see if it drops to 650rpms but I think I found my leak.... this would explain just about everything: low vacuum reading, motor not dying when all orifices were plugged, and most importantly high idle.
If this does fix it then I have to change the (not so) clever title to this thread
DOH!