00vi High idle (1900 rpm) with TPS disconnected
09-15-2010, 08:25 AM
#1
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00vi High idle (1900 rpm) with TPS disconnected
This is not right...
I've already checked my Throttle body adjustment screw and its as closed as its going to get...butterfly plate is almost fully sealed.
Whats going on? Only thing I can think of is I dont have a working adjustment screw on my IACV...its old and blew up on me (literally) when I installed the 00vi. Its still in there, just no Philips head.
But yea...thought this was weird. With TPS on and at 550ohms and with the new TPS procedure, it idles fine...around 740...but I think my ECU is doing all that.
I've already checked my Throttle body adjustment screw and its as closed as its going to get...butterfly plate is almost fully sealed.
Whats going on? Only thing I can think of is I dont have a working adjustment screw on my IACV...its old and blew up on me (literally) when I installed the 00vi. Its still in there, just no Philips head.
But yea...thought this was weird. With TPS on and at 550ohms and with the new TPS procedure, it idles fine...around 740...but I think my ECU is doing all that.
09-16-2010, 09:47 PM
#2
Just curious what about your throttle cable? is it pulled a tad bit too tight causing it to idle high.... Or if all else fails like I mentioned before I still have mine I can sell you....lol GL man.
09-17-2010, 05:47 PM
#3
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Nah throttle cable is perfect. The butterfly plate won't close anymore.
Have you taken your care for a long ride? Any stalls with the 5th gen IACV? If not, then please. I would like to see if the IACV is the problem.
Have you taken your care for a long ride? Any stalls with the 5th gen IACV? If not, then please. I would like to see if the IACV is the problem.
09-17-2010, 07:48 PM
#4
Yeah man car rides great, not a low idle nor a real problem with cold starts, just need a tune and I'll be great again thanks forth help and yea I can get you that iacv just let me know you got pm gl man
09-17-2010, 08:48 PM
#5
If you're looking for a new IACV, I suggest picking up a pathfinder IACV '01 and '02 IIRC, same years as the 3.5 cable driven TB we use. I've been using it since my 00vi swap back in March. The only issue I've had with it is stalling at full lock coasting into a parking space, which is due to the removal of the fast idle cam or w/e its called for power steering on the 4th gen IACV. Other than that I'd say it ides just as good as stock.
09-17-2010, 08:55 PM
#7
This is not right...
I've already checked my Throttle body adjustment screw and its as closed as its going to get...butterfly plate is almost fully sealed.
Whats going on? Only thing I can think of is I dont have a working adjustment screw on my IACV...its old and blew up on me (literally) when I installed the 00vi. Its still in there, just no Philips head.
But yea...thought this was weird. With TPS on and at 550ohms and with the new TPS procedure, it idles fine...around 740...but I think my ECU is doing all that.
I've already checked my Throttle body adjustment screw and its as closed as its going to get...butterfly plate is almost fully sealed.
Whats going on? Only thing I can think of is I dont have a working adjustment screw on my IACV...its old and blew up on me (literally) when I installed the 00vi. Its still in there, just no Philips head.
But yea...thought this was weird. With TPS on and at 550ohms and with the new TPS procedure, it idles fine...around 740...but I think my ECU is doing all that.
09-18-2010, 06:07 AM
#10
I had the same issue with my 3.5 swap. With the TPS disconnected, it would idle at around 2000rpm. Once connected it would be around 750rpm. I logged some parameters with my EMU and found out that the ECU was pulling timing at idle to get the idle speed down to 750. My timing at idle with the TPS connected was 6* instead of 15*.
09-21-2010, 03:20 PM
#15
10-03-2010, 02:34 PM
#17
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New IACV arrived thanks to mista, which allowed me to adjust IACV Idle screw. Here's what happened:
-Car well warm
-Disconnected TPS (both connectors, Idle was 1600
-Adjusted IACV screw to lower RPM, could only lower to 1300.
-turned car off, connected TPS
-Turn car on, Idled fine, 650 rpm in neutral.
Car was running fine for 2 days, started up real good although I noticed the needle dip to 500 on cold starts. In a red light, in Drive, car shakes a bit. Nothing bad, but noticeable due to low idle. THIS morning, car wouldnt even hold idle. I was completely let down when I attempted to start it. RPM's jumped to 1300 like normal cold start and dropped all the way down to a stall. (same thing that happens with 5th gen IACV)
The fck man? Opening the TB plate would only give me a higher idle. Why is my 00vi giving me such problems?
-Car well warm
-Disconnected TPS (both connectors, Idle was 1600
-Adjusted IACV screw to lower RPM, could only lower to 1300.
-turned car off, connected TPS
-Turn car on, Idled fine, 650 rpm in neutral.
Car was running fine for 2 days, started up real good although I noticed the needle dip to 500 on cold starts. In a red light, in Drive, car shakes a bit. Nothing bad, but noticeable due to low idle. THIS morning, car wouldnt even hold idle. I was completely let down when I attempted to start it. RPM's jumped to 1300 like normal cold start and dropped all the way down to a stall. (same thing that happens with 5th gen IACV)
The fck man? Opening the TB plate would only give me a higher idle. Why is my 00vi giving me such problems?
10-03-2010, 03:32 PM
#18
I'm glad you recieved the iacv man but sorry that it didn't resolve your problem I wish I could be there to help you trouble shoot it... anything new that's going on man, what if you hold the gas while you start it will it hold a good idle?
10-05-2010, 11:35 AM
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nope. Can't figure out why my 00vi is giving me such a high idle. I really don't have the tools to properly check for a vacuum leak, but i honestly don't hear anything unusual aside from the typical 00vi whisp when reving.
Performance is fine. Just annoying idle.
Performance is fine. Just annoying idle.
10-06-2010, 07:59 AM
#23
I'm assuming you have a remoted mounted A32 IACV. If so, you want the TB plate open enough to bypass air on cold starts (look at an A32 TB with the wax filament for reference, A33B and A34 throttle plates are open too), and the IACV screw in stock position or somewhere in the middle (not sure where you have it) so it can electronically adjust up and down (maxed out in either direction=fail). The idea is the TB plate is open enough to get the car running before the air goes through the hose on the now remote mounted IACV, and then once it's warm, the IACV will bring the idle down electronically and they share the bypass like 60/40 or 30/70 or whatever. A good idle comes from the balance between the TB and the IACV, you don't want either fully open or closed which is what the problem sounds like.
Get your IACV back to a stock position and adjust the TPS to 4.V at WOT, reset the ECU. Crank open your TB screw (with the TPS calibrated from the top-down adjustments will stay in spec). Start the car, it'll idle high. Warm it up, then slowly bring down your TB screw 1/4 turn at a time until it idles roughly where you want (Closed position with good cold starts will be around 0.7/0.8 on the TPS). Leave it. Next time you start the car cold, if it won't stay on without feathering the gas, you need a little more TB opening, and then maybe a 1/8 turn down on the IACV to keep the idle low (when the percentage of TB opening goes up, the percentage of IACV opening goes down accordingly). Do this over the course of a week until it cold starts/idles perfect. If that doesn't work you have a vacuum leak or something else.
Get your IACV back to a stock position and adjust the TPS to 4.V at WOT, reset the ECU. Crank open your TB screw (with the TPS calibrated from the top-down adjustments will stay in spec). Start the car, it'll idle high. Warm it up, then slowly bring down your TB screw 1/4 turn at a time until it idles roughly where you want (Closed position with good cold starts will be around 0.7/0.8 on the TPS). Leave it. Next time you start the car cold, if it won't stay on without feathering the gas, you need a little more TB opening, and then maybe a 1/8 turn down on the IACV to keep the idle low (when the percentage of TB opening goes up, the percentage of IACV opening goes down accordingly). Do this over the course of a week until it cold starts/idles perfect. If that doesn't work you have a vacuum leak or something else.
10-07-2010, 06:13 PM
#25
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I'm sorry... but could you re-explain that? I'm following the procedure from the revised TPS adjustment here:
http://lyberty.com/car/Maxima_A32_do...NTB99-053b.pdf
No offense, but your method seems improvised. Given the time comsumption of having the remove the Throttle Body after every adjustment on the TB screw to recalibrate the TPS to the "feeler-gauge" procedure, it would just take way too long to do it your way.
I did this today:
-Removed 00vi
-Applied RTV to all gaskets / nipples.
-Loosend TB screw to approximetly the same opening as my 4th gen TB. (my 5th gen Throttle Body does NOT have that plunger thing some 5th gens have on the TB to help with cold starts.)
-Calibrated TPS to feeler gauge procedure
-Turned it on with everything connected,
Didn't stall. So far, letting it warm up, like the service bulletin above said so it "relearns the idle"
anyone know about this "relearn" procedure? Do i just let it warm up and thats it?
http://lyberty.com/car/Maxima_A32_do...NTB99-053b.pdf
No offense, but your method seems improvised. Given the time comsumption of having the remove the Throttle Body after every adjustment on the TB screw to recalibrate the TPS to the "feeler-gauge" procedure, it would just take way too long to do it your way.
I did this today:
-Removed 00vi
-Applied RTV to all gaskets / nipples.
-Loosend TB screw to approximetly the same opening as my 4th gen TB. (my 5th gen Throttle Body does NOT have that plunger thing some 5th gens have on the TB to help with cold starts.)
-Calibrated TPS to feeler gauge procedure
-Turned it on with everything connected,
Didn't stall. So far, letting it warm up, like the service bulletin above said so it "relearns the idle"
anyone know about this "relearn" procedure? Do i just let it warm up and thats it?
10-07-2010, 10:57 PM
#26
No offense taken. 00vi swaps are improvised, still a science in development : ) My car has perfect idle and cold starts in -40C to +30C temperature ranges without using a 'feeler guage' for the TPS. All I'm suggesting is providing stock-ish A32 sensor inputs to the ECU because that's what it wants. Here's one way of going about that.
The short is:
Starting with a freshly reset ECU...
1- Calibrate TPS to approx 4.0V at WOT (with TB uninstalled).
2- Make sure A32 IACV adjustment screw is in a stock-ish position so the ECU can electronically increase/decrease the air bypass as required (if the screw is maxed out up or down, it can't do this AFAIK).
3- With TB installed, freely adjust TB-plate stop screw ->while car is running.
4) Crudely get the first start idle to around 800-1100, at this setting the TB plate should be open enough for cold starts depending on how the IACV is mounted and the size of hose (open it up more as required for cold starts).
5) Drive the car, and let the IACV refine the idle automatically. Adjust in 1/8 - 1/4 turn up/down increments throughout the following days if further adjustment is required.
The longer explanation is:
I calibrate the TPS at WOT with the TB uninstalled, to make sure I'm getting approx 4.0V and proper WOT fueling. Thats all that really matters, once the top end of the TPS potentiometer is set, the lower end of the scale takes care of itself (and so you can adjust the TB plate set screw without worrying about the TPS reading, the TPS reading and the plate are 'locked in' to eachother so they go up and down together on a scale of 0-100%/0-4.0V - each turn of the set screw will raise or lower the TPS reading accordingly). This way, wherever the plate is (whether fully closed or fully opened, the amount of air being drawn in (the MAF signal) and the TPS signal will be in accordance with each other. If the plate is closed but the TPS signal is high (user error), the TPS/MAF signals are discordant and will wonk out the IACV.
Because the A33 TB doesn't have that wax filament/plunger, the throttle plate needs to be open to a similar setting to the A32 cold start setting (which is higher than 0.5V, probably around 0.7 or 8 due to that hardened filament), and once the car warms up and eventually develops a driving pattern, the IACV will idle automatically based on the freak'n weather, assuming its not manually maxed out in either direction. It may require a 1/4 turn or so, but this can be done in the weeks to come if the idle doesnt settle on its own, and is WAAY easier than dealing with a carb.
The short is:
Starting with a freshly reset ECU...
1- Calibrate TPS to approx 4.0V at WOT (with TB uninstalled).
2- Make sure A32 IACV adjustment screw is in a stock-ish position so the ECU can electronically increase/decrease the air bypass as required (if the screw is maxed out up or down, it can't do this AFAIK).
3- With TB installed, freely adjust TB-plate stop screw ->while car is running.
4) Crudely get the first start idle to around 800-1100, at this setting the TB plate should be open enough for cold starts depending on how the IACV is mounted and the size of hose (open it up more as required for cold starts).
5) Drive the car, and let the IACV refine the idle automatically. Adjust in 1/8 - 1/4 turn up/down increments throughout the following days if further adjustment is required.
The longer explanation is:
I calibrate the TPS at WOT with the TB uninstalled, to make sure I'm getting approx 4.0V and proper WOT fueling. Thats all that really matters, once the top end of the TPS potentiometer is set, the lower end of the scale takes care of itself (and so you can adjust the TB plate set screw without worrying about the TPS reading, the TPS reading and the plate are 'locked in' to eachother so they go up and down together on a scale of 0-100%/0-4.0V - each turn of the set screw will raise or lower the TPS reading accordingly). This way, wherever the plate is (whether fully closed or fully opened, the amount of air being drawn in (the MAF signal) and the TPS signal will be in accordance with each other. If the plate is closed but the TPS signal is high (user error), the TPS/MAF signals are discordant and will wonk out the IACV.
Because the A33 TB doesn't have that wax filament/plunger, the throttle plate needs to be open to a similar setting to the A32 cold start setting (which is higher than 0.5V, probably around 0.7 or 8 due to that hardened filament), and once the car warms up and eventually develops a driving pattern, the IACV will idle automatically based on the freak'n weather, assuming its not manually maxed out in either direction. It may require a 1/4 turn or so, but this can be done in the weeks to come if the idle doesnt settle on its own, and is WAAY easier than dealing with a carb.
11-23-2010, 11:54 AM
#27
[quote=bamboomerang;7766167]Because the A33 TB doesn't have that wax filament/plunger, the throttle plate needs to be open to a similar setting to the A32 cold start setting (which is higher than 0.5V, probably around 0.7 or 8 due to that hardened filament [quote]
what exactly did you mean by 0,5v? setting the stop screw or the tps?
what exactly did you mean by 0,5v? setting the stop screw or the tps?
11-23-2010, 02:57 PM
#28
Once WOT position is calibrated to approx. 4.0 (calibrating the TPS), adjusting the stop screw will bring the closed position TPS reading up/down, depending on which way you turn the screw. The TPS turns when the throttle plate turns, either from the throttle cable or opening/closing the stop screw.
The stop screw dictates A) the closed throttle position TPS reading for the ECU and B) the amount of air available byway of the throttle chamber to help the motor idle- which C) consequently dictates how much more bypass air is needed through the IACV while the car is idling/in closed throttle position.
By this logic, running without an IACV would mean 100% of the idle air needs to come through the throttle body, and so the throttle plate opening/TPS reading needs to be slightly higher so enough air/fuel can be had to keep the car running at ____ idle RPM. Running an 00vi swap, with an a32 IACV hose that is smaller than stock, means more air needs to come through the TB to compensate for the smaller IACV hose, and so the plate opening/TPS reading need to be slightly greater.
The stop screw dictates A) the closed throttle position TPS reading for the ECU and B) the amount of air available byway of the throttle chamber to help the motor idle- which C) consequently dictates how much more bypass air is needed through the IACV while the car is idling/in closed throttle position.
By this logic, running without an IACV would mean 100% of the idle air needs to come through the throttle body, and so the throttle plate opening/TPS reading needs to be slightly higher so enough air/fuel can be had to keep the car running at ____ idle RPM. Running an 00vi swap, with an a32 IACV hose that is smaller than stock, means more air needs to come through the TB to compensate for the smaller IACV hose, and so the plate opening/TPS reading need to be slightly greater.
06-18-2011, 07:06 PM
#29
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^ im going to try that bamboomerang. Your method makes sense, I was just sticking to the FSM procedure, even though I have a 00vi swap, the FSM probably won't help me much since airways have changed/been altered.
THIS^ is what im talking about, this is the big mystery.
I had the same issue with my 3.5 swap. With the TPS disconnected, it would idle at around 2000rpm. Once connected it would be around 750rpm. I logged some parameters with my EMU and found out that the ECU was pulling timing at idle to get the idle speed down to 750. My timing at idle with the TPS connected was 6* instead of 15*.
Last edited by shadyonedeath; 06-18-2011 at 07:17 PM.
08-04-2011, 12:11 AM
#30
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I just bought a brand new IACV and installed it... but when i try to adjust my base idle (TPS unplugged) it STILL idles @ 1300.
There's ZERO vacuum leaks, every single seal from LIM to TB is sealed with new gaskets. I already did a pressure test and it hold vacuum (plug TB).
Does anyone know if 99's have a different idle procedure? Im doing what the 99 FSM says and it still wont drop to 550 rpms with the TPS disconnected. Or is it just my 00vi swap? Can anyone else with a 00vi disconnect their TPS and check their base idle?
NOTE: With TPS connected, IACV controls idle fine at 750rpm...but the damn FSm says it should be ~550 when disconnected to adjust the idle correctly. TPS is set correctly via new TPS procedure with feeler gauge and at 550ohms.
Common guys, I need some brain storming here .
There's ZERO vacuum leaks, every single seal from LIM to TB is sealed with new gaskets. I already did a pressure test and it hold vacuum (plug TB).
Does anyone know if 99's have a different idle procedure? Im doing what the 99 FSM says and it still wont drop to 550 rpms with the TPS disconnected. Or is it just my 00vi swap? Can anyone else with a 00vi disconnect their TPS and check their base idle?
NOTE: With TPS connected, IACV controls idle fine at 750rpm...but the damn FSm says it should be ~550 when disconnected to adjust the idle correctly. TPS is set correctly via new TPS procedure with feeler gauge and at 550ohms.
Common guys, I need some brain storming here .
08-04-2011, 10:21 PM
#31
you're not the only one! 00vi 1k rpm idle, tps connected
I just bought a brand new IACV and installed it... but when i try to adjust my base idle (TPS unplugged) it STILL idles @ 1300.
There's ZERO vacuum leaks, every single seal from LIM to TB is sealed with new gaskets. I already did a pressure test and it hold vacuum (plug TB).
Does anyone know if 99's have a different idle procedure? Im doing what the 99 FSM says and it still wont drop to 550 rpms with the TPS disconnected. Or is it just my 00vi swap? Can anyone else with a 00vi disconnect their TPS and check their base idle?
NOTE: With TPS connected, IACV controls idle fine at 750rpm...but the damn FSm says it should be ~550 when disconnected to adjust the idle correctly. TPS is set correctly via new TPS procedure with feeler gauge and at 550ohms.
.
There's ZERO vacuum leaks, every single seal from LIM to TB is sealed with new gaskets. I already did a pressure test and it hold vacuum (plug TB).
Does anyone know if 99's have a different idle procedure? Im doing what the 99 FSM says and it still wont drop to 550 rpms with the TPS disconnected. Or is it just my 00vi swap? Can anyone else with a 00vi disconnect their TPS and check their base idle?
NOTE: With TPS connected, IACV controls idle fine at 750rpm...but the damn FSm says it should be ~550 when disconnected to adjust the idle correctly. TPS is set correctly via new TPS procedure with feeler gauge and at 550ohms.
.
. just replaced my triple used LIM and UIM gaskets and i still have the problem. my tps is set 3.97K ohms @ WOT and 0.79K ohms closed. this is what its supposed to read. i also have a auto tranny tps (2 plugs vs 1 plug for the manual) not sure if that matters.Bamboomerang and I have been trying to solve this problem over at TMEC but i thought i might open up and post here.
have any pics of your iacv setup? my idle screw does nothing for adjusting idle
what size is your hose leading to TB? mine is 5/8"
Common guys, I need some brain storming here
08-05-2011, 12:47 AM
#32
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your TPS is not supposed to be calibrated by OHMS but by a feeler gauge on the closed throttle sensor on the TPS. Maybe your TPS is sending a signal that the throttle is open.
http://lyberty.com/car/Maxima_A32_do...NTB99-053b.pdf
http://lyberty.com/car/Maxima_A32_do...NTB99-053b.pdf
08-05-2011, 10:16 AM
#33
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Sorry to jump off topic, ive just been doing as much research as possible before the install to avoid future problems/ obstacles.
Thanks, GL with everything, hope you figure it out.
Last edited by Lingling757; 08-05-2011 at 07:59 PM.
08-22-2011, 08:53 AM
#34
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Im starting to believe my IACV portion of my ECU is fried.
Here are some symptoms:
-Car idles at 1300+ with TPS unlpugged (not normal, should drop down to 500 but iacv never closes)
-Because IACV never closes, when TPS is plugged back in, the ECU sets itself to 750 rpm in Neutral. BUT, this In MY opinion is only because of the ECU pulling timing. (bad right?)
-When in DRIVE, the ecu ALWAYS tries to go lower than 650rpm, it will sometimes hunt down to 550 and make the car shake. It annoys me because It keeps wanting to drop it down despite being able to manage itself at 750rpm in neutral.
-car starts up well, no cold start failures.
Here are some symptoms:
-Car idles at 1300+ with TPS unlpugged (not normal, should drop down to 500 but iacv never closes)
-Because IACV never closes, when TPS is plugged back in, the ECU sets itself to 750 rpm in Neutral. BUT, this In MY opinion is only because of the ECU pulling timing. (bad right?)
-When in DRIVE, the ecu ALWAYS tries to go lower than 650rpm, it will sometimes hunt down to 550 and make the car shake. It annoys me because It keeps wanting to drop it down despite being able to manage itself at 750rpm in neutral.
-car starts up well, no cold start failures.
06-02-2013, 12:24 PM
#35
Any updates on this? I jsut put my 3.0 back in with the 00vi, and it either idles high (1300rpm with descent AFR) or idles around 750 with LEAN AFR...I havent tried to calibrate the TPS yet, but will soon. Just wanted to ask if your problem was ever resolved..
EDIT: I tried calibrating it with the 0.012" and 0.016" feeler gauge. As per the service bullitin http://www.lyberty.com/car/Maxima_A3...NTB99-053b.pdf, I should see 0 ohms when the 0.012" gauge is being used, but I see about 4.4 ohms, and I cannot get resistance to go down from there. The continuity does stop at 0.016" though, so I know that I'm at least performing this test correctly. Any input on this?
EDIT: I tried calibrating it with the 0.012" and 0.016" feeler gauge. As per the service bullitin http://www.lyberty.com/car/Maxima_A3...NTB99-053b.pdf, I should see 0 ohms when the 0.012" gauge is being used, but I see about 4.4 ohms, and I cannot get resistance to go down from there. The continuity does stop at 0.016" though, so I know that I'm at least performing this test correctly. Any input on this?
Last edited by Maximeltman; 06-02-2013 at 02:12 PM.
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