jdub;1131384 said:
No the vtv is the valve delay with the little air filter connected by vac line to the bottom of the dashpot, i know what your talking about on the vsv, but i have no tested that yet.
Stumped with high idle need help?
- Thread starter super7mgtepower
- Start date
No the vtv is the valve delay with the little air filter connected by vac line to the bottom of the dashpot, i know what your talking about on the vsv, but i have no tested that yet.
I guess ill give you guys the full blown story. Well it started out my valve covers were leaking oil into my spark plug galley, I had a coolant line from the bottom of the TB bust open so i removed the intake plenum to replace, also my starter had been clickin for a while perfect time to remove that (bleep bleep bleep) while intake was removed. Ive replaced all vac lines all gaskets and almost all the bigger hoses. The reason i asked about the bov is it was installed before start up. Before you all start ragging me about leaks in intake and TB ive checked for them.
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Supra87T;1131386 said:
Ok...whatever you say. I guess 1 out of 3 isn't bad, regardless of how unlikely it is :3d_frown:
My bad...I misread VTV to mean VSV.
The VTV can affect idle...you need to replace it.
What I'm trying to get you to do is narrow down the problem area, that's why I told you to block off the PCV and ISCV ports...this is easy to do. If the motor does not die, a pirate air leak is at least part of the problem...it's also the most common cause of a high idle.
You can check parts at random (like the ISCV) if you wish...it usually ends up chasing your tail though.
Well i found my vac leak under the powersteering res. there was a line not even attached, i havent even messed with that side, anyways hooked it back up, started car, idle still same only now when i rev over 3000 when it comes back down it goes to like 500 rpm and tries to die, usually catches its self and then idles high again. My dashpot isnt even touching the throttle lever and i dont have the replacement vtv yet. Is my dashpot no good?
The dashpot should be touching...here's the TSRM link on how to test it:
http://www.cygnusx1.net/supra/Library/TSRM/MK3/manual.aspx?Section=EC&P=8
You need the VTV before you can do anything with the dashpot
Did you block off the PCV and ISCV like I told you?
http://www.cygnusx1.net/supra/Library/TSRM/MK3/manual.aspx?Section=EC&P=8
You need the VTV before you can do anything with the dashpot
Did you block off the PCV and ISCV like I told you?
jdub;1132402 said:The dashpot should be touching...here's the TSRM link on how to test it:
http://www.cygnusx1.net/supra/Library/TSRM/MK3/manual.aspx?Section=EC&P=8
You need the VTV before you can do anything with the dashpot
Did you block off the PCV and ISCV like I told you?
yup it cut the motor off, at first it didnt then i found my leak. Thanks again i let you know what happens.
Finally problem found.:biglaugh: The Egr system has the valve hung open and the modulator is leaking. I plan to just get block off plates, the vacum i had found unattached goes to the power steering, what i figure has happened is the previous owner (2 years ago) had high idle couldnt find the leak put the idle screw all the way closed and adjusted the dashpot out of the way, no wonder i only got it for $1500 with new clutch and head rebuild which was done by toyota (receipts):evil2:. So its all good im gonna get this fixed and the sups should be high on its heel's thanks for all your info it was very helpful. Also the reason my rpms would drop and try to die after a good rev was that the idle screw was closed (found that way).
<Cars run like shit with vacum leaks.>:3d_frown:
<Cars run like shit with vacum leaks.>:3d_frown:
I would keep the EGR if I were you...the ECU is tuned for it. Without it you risk detonation under part throttle load conditions. The EGR will not cause high idle, but will cause idle to be rough or drop and almost die (if it's stuck open) like you saw.
You will still need a VTV for the dashpot to work correctly, and it will need to be adjusted correctly per the TSTM link I posted above...I suspect that's what is causing idle to be high.
The adjustment screw comes from the factory fully closed...that is where it's suppose to be. Later model 7M's don't have the screw at all (to prevent people from messing with it). Do not adjust it out...you will do the same thing as a vac leak if you do.
You will still need a VTV for the dashpot to work correctly, and it will need to be adjusted correctly per the TSTM link I posted above...I suspect that's what is causing idle to be high.
The adjustment screw comes from the factory fully closed...that is where it's suppose to be. Later model 7M's don't have the screw at all (to prevent people from messing with it). Do not adjust it out...you will do the same thing as a vac leak if you do.
Well the dashpot is not touching the linkage, so what im suspecting is that the screw has been adjusted away from the dashpot.
Reason for: The idle screw adj. was closed completely and was not done by me.
So I called a buddy hes an old Toyota tech. I told him what was going on, Lets say the previous owner had a vac leak couldnt find it so to sell the car off he had it adjusted as low as he could (closed idle screw, remove dashpot adjustment away, also i did not mention when i first had to remove intake the egr line was not tightly connected (venting).
I removed AFM hose and the vacum hose for the power steering pump was unpluged (major vac leak) as soon as hooked it back up and put everything back together ran the car my idle hadnt changed but when the rpms go up and then come back down they would fall very low and struggle to run (idle screw closed) causing no air to get through when throttle closed. The ISC was trying to compensate for the prob.
Idle was still high so kept checking for leaks. The modulator's for the EGR's go bad over time get rotted and brittle causing leaks, also EGR's are known for valves to get hung open causing vac leak (over time). Also their is carb debris all over EGR and valve Cover by the modulator (before i removed parts for replacing and painting).
The best thing about egr block off's is the ECU does not control the EGR system it is vacumed. Worst case is one of the cyl. will run a little more rich.
Reason for: The idle screw adj. was closed completely and was not done by me.
So I called a buddy hes an old Toyota tech. I told him what was going on, Lets say the previous owner had a vac leak couldnt find it so to sell the car off he had it adjusted as low as he could (closed idle screw, remove dashpot adjustment away, also i did not mention when i first had to remove intake the egr line was not tightly connected (venting).
I removed AFM hose and the vacum hose for the power steering pump was unpluged (major vac leak) as soon as hooked it back up and put everything back together ran the car my idle hadnt changed but when the rpms go up and then come back down they would fall very low and struggle to run (idle screw closed) causing no air to get through when throttle closed. The ISC was trying to compensate for the prob.
Idle was still high so kept checking for leaks. The modulator's for the EGR's go bad over time get rotted and brittle causing leaks, also EGR's are known for valves to get hung open causing vac leak (over time). Also their is carb debris all over EGR and valve Cover by the modulator (before i removed parts for replacing and painting).
The best thing about egr block off's is the ECU does not control the EGR system it is vacumed. Worst case is one of the cyl. will run a little more rich.
super7mgtepower;1133185 said:
The idle adjust screw I'm referring to is on top of the TB...regardless of what your Tech friend says (if he's even talking about this screw), it should be fully closed on the 7M. It specifically says so in the TCCS book I have.
The dashpot screw is a different story...it is not an idle adjust screw per say, but enables the dashpot to keep the TB plate from snapping shut. Primarily for emissions, but also to help the transition to idle.
super7mgtepower said:
This was simply another vac leak...it is not possible for the EGR to stick open due to vac. The source is on the IC pipe side of the TB plate...vac can only get to the EGR modulator if the TB plate is open (above idle). A bad modulator will cause the EGR not to function at all though...vac is applied to the modulator from above idle to ~4000 RPM where the EGR VSV gets a signal to cut vac from the TCCS. Based on what you've said, it is highly unlikely the EGR is affecting your idle...that is unless the EGR valve itself is stuck open due to carbon build-up.
super7mgtepower said:
Ummm...not even close. On the 7M it works like I described above. In that RPM range, exhaust gas displaces air in the cylinders...remove it and more air is allowed in by volume. That means a lean condition is possible in the EGR activation range = detonation under load.
Plus, like tlo86 said, the EGR helps gas milage at cruise and it has zero effect on total HP produced since it is inop above ~4000 RPM.
Might want to start listening...I know what I'm talking about on this one
jdub;1133230 said:The idle adjust screw I'm referring to is on top of the TB...regardless of what your Tech friend says (if he's even talking about this screw), it should be fully closed on the 7M. It specifically says so in the TCCS book I have.
The dashpot screw is a different story...it is not an idle adjust screw per say, but enables the dashpot to keep the TB plate from snapping shut. Primarily for emissions, but also to help the transition to idle.
This was simply another vac leak...it is not possible for the EGR to stick open due to vac. The source is on the IC pipe side of the TB plate...vac can only get to the EGR modulator if the TB plate is open (above idle). A bad modulator will cause the EGR not to function at all though...vac is applied to the modulator from above idle to ~4000 RPM where the EGR VSV gets a signal to cut vac from the TCCS. Based on what you've said, it is highly unlikely the EGR is affecting your idle.
Ummm...not even close. On the 7M it works like I described above. In that RPM range, exhaust gas displaces air in the cylinders...remove it and more air is allowed in by volume. That means a lean condition is possible in the EGR activation range = detonation under load.
Plus, like tlo86 said, the EGR helps gas milage at cruise and it has zero effect on total HP produced since it is inop above ~4000 RPM.
Might want to start listening...I know what I'm talking about on this one
1.Okay the idle adjust screw is that little tunnel running off the Tb with a screw in it. If we are talking about the same idle adjust screw it is not ment to be closed, its a by pass
2. The EGR is not stuck due to vac its from carb build up, and it is leaking from two different spots.
3. The dashpot is not making contact with the throttle linkage therefore it can't cause the idle to go up.
1. New ISC verify that it works.
2. Verify all vacums are secured and complete.
3. I have removed the dashpot.
4. Egr leaking has not been removed or messed with and valve will not close.
My idle is still high.
:icon_biggIs the EGR not making my idle high still.:icon_bigg
Look...I realize that 20 year old's are all knowing. Been there, done that...I'm going to say this one more time:
I don't see how it can be more clear than that...once you got rid of the vac leaks, the ECU had to re-learn idle. That's why:
It takes time...an ECU re-set will help. Opening up the adjustment screw simple provides a source of pirate air on this engine...you're inducing a problem.
A stuck open EGR Valve will cause a rough idle...if the ECU is in idle learn mode, it will make it more pronounced. You need to fix the EGR...and, not just remove it. There is no way the EGR valve can cause a high idle.
You are correct about the dashpot...not touching the linkage should have no effect on idle. It still needs to be fixed too
TCCS Manual said:
I don't see how it can be more clear than that...once you got rid of the vac leaks, the ECU had to re-learn idle. That's why:
super7mgtepower said:
It takes time...an ECU re-set will help. Opening up the adjustment screw simple provides a source of pirate air on this engine...you're inducing a problem.
A stuck open EGR Valve will cause a rough idle...if the ECU is in idle learn mode, it will make it more pronounced. You need to fix the EGR...and, not just remove it. There is no way the EGR valve can cause a high idle.
You are correct about the dashpot...not touching the linkage should have no effect on idle. It still needs to be fixed too
How long does it take for the ecu to learn something, how many drive cycles? I have service manuals two different ones, i dont have a training one. Most of my info is comming from a Toyota mast. tech who has owned a couple of these cars, i dont doubt him. Im not exactly saying its my EGR but its the only thing that's leaking I know the EGR wont cause high idle as it is just for emisions purpose's but what else am i missing (if its broke fix it). And if the dashpot is making my idle fall real low why does it come up fall back down and then come up again? I dont doubt you intelligance, from your post it seemed like you were not understanding what i was talking about. But i have removed the dashpot (not perm.) but just to test that is not causing high idle. The vacum hose i found disconnected was the power steering idle up, problems started after reconnect and idle did not go down. I work for Ford im use to stupid problems causing stupid things to happen what do you expect. sorry.
Ok...here's what I understand so far:
1) No codes
2) Known good ISCV
3) Engine dies when PCV and ISCV hosed are blocked off (i.e. no more pirate air)
4) The EGR Valve is stuck open due to carbon build-up
Even a Master Tech can be wrong if he doesn't have the right info...what I said only applies to engines with an ISCV (like the 7M). Think about it...the later model motors don't even have the adjustment screw (like I said). Mine doesn't
The EGR has another impact...what I posted. If you're going to run without it, you need a standalone EMS or a JDM ECU if you stay stock. It's function is broader than just emissions.
First - pull the EFI fuse in the box under the hood for a minute or so and put it back.
Second - Fully close the TB adjustment screw.
Third - Run the motor till it warms up and report back.
You might want to check for air leaks in the accordion hose between the AFM and turbo.
1) No codes
2) Known good ISCV
3) Engine dies when PCV and ISCV hosed are blocked off (i.e. no more pirate air)
4) The EGR Valve is stuck open due to carbon build-up
Even a Master Tech can be wrong if he doesn't have the right info...what I said only applies to engines with an ISCV (like the 7M). Think about it...the later model motors don't even have the adjustment screw (like I said). Mine doesn't
The EGR has another impact...what I posted. If you're going to run without it, you need a standalone EMS or a JDM ECU if you stay stock. It's function is broader than just emissions.
First - pull the EFI fuse in the box under the hood for a minute or so and put it back.
Second - Fully close the TB adjustment screw.
Third - Run the motor till it warms up and report back.
You might want to check for air leaks in the accordion hose between the AFM and turbo.
So does disconnecting the battery for like 30 mins. not reset the ecu?
Ive made sure the accordian hose has no leaks.
Does the ecu have to go through certain drive cycles for idle? Like Ford's reset ecm you warm motor 5 mins. turn a/c on idle 5 mins. Then drive with cycling a/c.
Ive made sure the accordian hose has no leaks.
Does the ecu have to go through certain drive cycles for idle? Like Ford's reset ecm you warm motor 5 mins. turn a/c on idle 5 mins. Then drive with cycling a/c.
Disconnecting the battery will do it. The 7M ECU does "learn" during driving, but it should have no effect on the idle issue. Also make sure there are no leaks/cracks on the two rubber hoses from the accordian to the ISCV.
Confirm the powersteering vac line is connected to the nipple on the bottom of the accordion hose.
Your idle varies between 1000-1300 RPM when the motor is warm, correct?
Confirm the powersteering vac line is connected to the nipple on the bottom of the accordion hose.
Your idle varies between 1000-1300 RPM when the motor is warm, correct?
jdub;1133341 said:
All hoses are new. except accordian but i have checked it.
jdub said:
Check.
jdub said:
Since ive connected the p/s line it stays at 1000, also the idle adj. screw is to stay closed? Most cars is opened.
super7mgtepower;1133350 said:
Ok...this is getting frustrating...How many times to I have to say this?
TCCS Manual said:
Is there a problem with my English? Based on your 1000 RPM idle speed, if the adjustment screw is open, it's probably the reason or part of the reason why.
Jeez man...how can you expect a guy to help you if you're going to refuse to believe something that is about as black & white as it gets.