GT40 Charcoal Cannister Line Input / Idle Issue
01-19-2008, 06:39 PM
#1
Thread Starter
Join Date: Nov 2007
Posts: 4
GT40 Charcoal Cannister Line Input / Idle Issue
1993 Notch
5.0, GT40 Upper and Lower, E303, Edelbrock Alum Heads
73mm Calipers - Stock Master Cylinder and Brake Booster
5-SPD
Hi, I'm Dan - first time poster - but long time consumer of the information you guys put out. Thanks - you've all helped me out many times.
3 Questions:
1. Just to confirm I'm not going crazy - the GT40 (non-Cobra or Explorer) Upper Intake doesn't have a Charcoal Cannister Line Input in toward the front underside of the manifold, like the stocker, does it?
2. Assuming my #1 is true - does anyone have an opinion on how to hook up your Charcoal Cannister (yes, I want to keep it) to this type GT40? I've found no opinions on this posted.
3. I'm having the classic "hanging idle" problem that I've read a million posts about - though I've only seen a couple of posts mention it, I think I've got it down to a bad Brake Booster (the idle hangs at 1300-1400 until you bring the car to a complete stop - even when coasting long distances - and then it goes down to 800 or so as the car comes to a stop - I know, weird) - I've done all the stuff with the IAC, the MAF, the TPS, EGR, run the codes, etc etc - all the classic idle stuff. No resolution. So I did the diagnostic test on the Brake Booster (because I was looking for a vacuum problem) as directed in the Ford Service Manual to see if it was bad - and it seemed to fail their test. That being said, I have 73mm brake calipers and a stock master cylinder and brake booster right now - so I'm not sure how that would affect the validity of the test. Right now my plan is to step up to a 94 Master Cylinder and Brake Booster (per this site - www.sn95brakes.com). I hope this will cure my not-so-great brake feel, as well as the hanging idle issue. If anyone has any wisdom to offer on this issue I'm all ears.
Thanks,
Dan
5.0, GT40 Upper and Lower, E303, Edelbrock Alum Heads
73mm Calipers - Stock Master Cylinder and Brake Booster
5-SPD
Hi, I'm Dan - first time poster - but long time consumer of the information you guys put out. Thanks - you've all helped me out many times.
3 Questions:
1. Just to confirm I'm not going crazy - the GT40 (non-Cobra or Explorer) Upper Intake doesn't have a Charcoal Cannister Line Input in toward the front underside of the manifold, like the stocker, does it?
2. Assuming my #1 is true - does anyone have an opinion on how to hook up your Charcoal Cannister (yes, I want to keep it) to this type GT40? I've found no opinions on this posted.
3. I'm having the classic "hanging idle" problem that I've read a million posts about - though I've only seen a couple of posts mention it, I think I've got it down to a bad Brake Booster (the idle hangs at 1300-1400 until you bring the car to a complete stop - even when coasting long distances - and then it goes down to 800 or so as the car comes to a stop - I know, weird) - I've done all the stuff with the IAC, the MAF, the TPS, EGR, run the codes, etc etc - all the classic idle stuff. No resolution. So I did the diagnostic test on the Brake Booster (because I was looking for a vacuum problem) as directed in the Ford Service Manual to see if it was bad - and it seemed to fail their test. That being said, I have 73mm brake calipers and a stock master cylinder and brake booster right now - so I'm not sure how that would affect the validity of the test. Right now my plan is to step up to a 94 Master Cylinder and Brake Booster (per this site - www.sn95brakes.com). I hope this will cure my not-so-great brake feel, as well as the hanging idle issue. If anyone has any wisdom to offer on this issue I'm all ears.
Thanks,
Dan
01-19-2008, 06:52 PM
#2
5th Gear Member
Join Date: Jan 2006
Location: Puerto Rico
Posts: 3,926
RE: GT40 Charcoal Cannister Line Input / Idle Issue
ORIGINAL: m002922
1993 Notch
5.0, GT40 Upper and Lower, E303, Edelbrock Alum Heads
73mm Calipers - Stock Master Cylinder and Brake Booster
5-SPD
Hi, I'm Dan - first time poster - but long time consumer of the information you guys put out. Thanks - you've all helped me out many times.
3 Questions:
1. Just to confirm I'm not going crazy - the GT40 (non-Cobra or Explorer) Upper Intake doesn't have a Charcoal Cannister Line Input in toward the front underside of the manifold, like the stocker, does it?
2. Assuming my #1 is true - does anyone have an opinion on how to hook up your Charcoal Cannister (yes, I want to keep it) to this type GT40? I've found no opinions on this posted.
3. I'm having the classic "hanging idle" problem that I've read a million posts about - though I've only seen a couple of posts mention it, I think I've got it down to a bad Brake Booster (the idle hangs at 1300-1400 until you bring the car to a complete stop - even when coasting long distances - and then it goes down to 800 or so as the car comes to a stop - I know, weird) - I've done all the stuff with the IAC, the MAF, the TPS, EGR, run the codes, etc etc - all the classic idle stuff. No resolution. So I did the diagnostic test on the Brake Booster (because I was looking for a vacuum problem) as directed in the Ford Service Manual to see if it was bad - and it seemed to fail their test. That being said, I have 73mm brake calipers and a stock master cylinder and brake booster right now - so I'm not sure how that would affect the validity of the test. Right now my plan is to step up to a 94 Master Cylinder and Brake Booster (per this site - www.sn95brakes.com). I hope this will cure my not-so-great brake feel, as well as the hanging idle issue. If anyone has any wisdom to offer on this issue I'm all ears.
Thanks,
Dan
1993 Notch
5.0, GT40 Upper and Lower, E303, Edelbrock Alum Heads
73mm Calipers - Stock Master Cylinder and Brake Booster
5-SPD
Hi, I'm Dan - first time poster - but long time consumer of the information you guys put out. Thanks - you've all helped me out many times.
3 Questions:
1. Just to confirm I'm not going crazy - the GT40 (non-Cobra or Explorer) Upper Intake doesn't have a Charcoal Cannister Line Input in toward the front underside of the manifold, like the stocker, does it?
2. Assuming my #1 is true - does anyone have an opinion on how to hook up your Charcoal Cannister (yes, I want to keep it) to this type GT40? I've found no opinions on this posted.
3. I'm having the classic "hanging idle" problem that I've read a million posts about - though I've only seen a couple of posts mention it, I think I've got it down to a bad Brake Booster (the idle hangs at 1300-1400 until you bring the car to a complete stop - even when coasting long distances - and then it goes down to 800 or so as the car comes to a stop - I know, weird) - I've done all the stuff with the IAC, the MAF, the TPS, EGR, run the codes, etc etc - all the classic idle stuff. No resolution. So I did the diagnostic test on the Brake Booster (because I was looking for a vacuum problem) as directed in the Ford Service Manual to see if it was bad - and it seemed to fail their test. That being said, I have 73mm brake calipers and a stock master cylinder and brake booster right now - so I'm not sure how that would affect the validity of the test. Right now my plan is to step up to a 94 Master Cylinder and Brake Booster (per this site - www.sn95brakes.com). I hope this will cure my not-so-great brake feel, as well as the hanging idle issue. If anyone has any wisdom to offer on this issue I'm all ears.
Thanks,
Dan
3. That is not a problem, the "hanging idle" = the dashpot function (anytime VSS input is > 6MPH) is working.... BTW, that is a "condition" I have also found in OBD-II/manual transmission systems.... do suggest to do a base idle reset procedure ....800 rpms is too high of an idle set-point.... + (if you haven't by now).... you may look into upgrading the rubber brake line sections with braided lines.
01-19-2008, 07:08 PM
#3
Thread Starter
Join Date: Nov 2007
Posts: 4
RE: GT40 Charcoal Cannister Line Input / Idle Issue
"1 & 2. A manifold vacuum port you could instal a "Y" adapter will do. "
Can I just "Y" into the PCV tube, should that do it?
"3. That is not a problem, the "hanging idle" = the dashpot function (anytime VSS input is > 6MPH) is working.... BTW, that is a "condition" I have also found in OBD-II/manual transmission systems.... do suggest to do a base idle reset procedure ....800 rpms is too high of an idle set-point.... + (if you haven't by now).... you may look into upgrading the rubber brake line sections with braided lines."
I think what you're saying here is that it does that (hang the idle) by design (I'm not familar with dashpot function - I'll have to do some research about that). However, I know my car did not do this when stock, and it also did not do it when I first installed my heads, cam, and upper and lower intake - this started fairly recently. But maybe I'm misudnerstanding what you're saying. I did a base idle reset after all the modifications - that did not fix the issue. Another interesting note is that it doesn't seem to do it as badly when the car is first warming up. I said 800 on the idle, but it's probably more about 750 once everything settles down.
The braided brake lines are a good tip - especially since I'm going to have to bleed the system anyway.
Thanks for the help - let me know I'm missing.
Can I just "Y" into the PCV tube, should that do it?
"3. That is not a problem, the "hanging idle" = the dashpot function (anytime VSS input is > 6MPH) is working.... BTW, that is a "condition" I have also found in OBD-II/manual transmission systems.... do suggest to do a base idle reset procedure ....800 rpms is too high of an idle set-point.... + (if you haven't by now).... you may look into upgrading the rubber brake line sections with braided lines."
I think what you're saying here is that it does that (hang the idle) by design (I'm not familar with dashpot function - I'll have to do some research about that). However, I know my car did not do this when stock, and it also did not do it when I first installed my heads, cam, and upper and lower intake - this started fairly recently. But maybe I'm misudnerstanding what you're saying. I did a base idle reset after all the modifications - that did not fix the issue. Another interesting note is that it doesn't seem to do it as badly when the car is first warming up. I said 800 on the idle, but it's probably more about 750 once everything settles down.
The braided brake lines are a good tip - especially since I'm going to have to bleed the system anyway.
Thanks for the help - let me know I'm missing.
01-19-2008, 07:22 PM
#4
5th Gear Member
Join Date: Feb 2006
Location:
Posts: 3,768
RE: GT40 Charcoal Cannister Line Input / Idle Issue
I don't know if you'd want to Y the PCV tube. That's a metered amount of vacuum created at the PCV valve. Changing this might alter your idle as well as other things. I don't know anything about the intake you have, but if it doesn't have a fitting, andyou want your charcoal cannister hooked up, you may have to drill your intake and install anotherfitting (boss?)for that line. Or maybe there is another vacuum line on your intake that can be Y'd with no problems; I don't know.
As an aside, my idle has hung before when I've had vacuum leaks in any of the hoses coming from my intake.
As an aside, my idle has hung before when I've had vacuum leaks in any of the hoses coming from my intake.
01-19-2008, 09:15 PM
#5
5th Gear Member
Join Date: Jan 2006
Location: Puerto Rico
Posts: 3,926
RE: GT40 Charcoal Cannister Line Input / Idle Issue
As long as the "hanging idle" is only noticeable when the car is moving = dashpot function. If it does it while stopped, that is a problem.
Regarding the "Y" alternative, the only exceptions would be to the PCV and the fuel pump regulator ports.
Regarding the "Y" alternative, the only exceptions would be to the PCV and the fuel pump regulator ports.
01-19-2008, 10:26 PM
#6
3rd Gear Member
Join Date: May 2006
Location:
Posts: 668
RE: GT40 Charcoal Cannister Line Input / Idle Issue
the dashpot is a tuning term. if you had a tweecer and if you were framilar with it you could change it, buy why. dont worry about it. it sounds like your car is healthy. if your intake does not have a place for it and your car runs good then i would just cap off the canister.
01-20-2008, 12:06 PM
#7
Thread Starter
Join Date: Nov 2007
Posts: 4
RE: GT40 Charcoal Cannister Line Input / Idle Issue
All - thanks for the replies - I'm now adding the Tweecer to my list . . .
It will be interesting to see if that solves the problem. I'm going to go ahead and do the master cylinder, booster (and while there do the Brake Lines as suggested) - if that doesn't fix the problem (which I am now guessing it won't) - then I guess I will spend some quality time with the Tweecer - thanks for the new lead and the advice.
It will be interesting to see if that solves the problem. I'm going to go ahead and do the master cylinder, booster (and while there do the Brake Lines as suggested) - if that doesn't fix the problem (which I am now guessing it won't) - then I guess I will spend some quality time with the Tweecer - thanks for the new lead and the advice.
01-20-2008, 05:28 PM
#8
Thread Starter
Join Date: Nov 2007
Posts: 4
RE: GT40 Charcoal Cannister Line Input / Idle Issue
For anyone following along out there with similar issues - I removed the the threaded plug just (about 1") downstream of the throttle body (the plug faces the front of the car), at the very beginning of the GT-40 Intake. I replaced this plug with a male NPT fitting going to a hose fitting - it seems like a good place to reroute the Charcoal Cannister output into the engine - this setup seems to work.
The plug that I removed is 21/32-18 (I checked it at the hardware store with one of the thread finders - good luck finding a male NPT to hose fitting that size - I can't even find one at Summit or on an internet search) . . . I replaced the metal plug with something roughly that size that is plastic (I think the flexibility of the plastic allowed me to not have to have the size exactly right) - I'm in the process of looking for a metal 21/32-18 male fitting into a 1/4 hose fitting (for longevity) . . . I'm not holding my breath.
If anyone out there is using a different size NPT male to hose fitting in this spot and wants to clue me in, I'm all ears.
The plug that I removed is 21/32-18 (I checked it at the hardware store with one of the thread finders - good luck finding a male NPT to hose fitting that size - I can't even find one at Summit or on an internet search) . . . I replaced the metal plug with something roughly that size that is plastic (I think the flexibility of the plastic allowed me to not have to have the size exactly right) - I'm in the process of looking for a metal 21/32-18 male fitting into a 1/4 hose fitting (for longevity) . . . I'm not holding my breath.
If anyone out there is using a different size NPT male to hose fitting in this spot and wants to clue me in, I'm all ears.
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