Alkorahil
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Posts posted by Alkorahil
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What exactly is an IVAC-ACC Valve/ regulator and what does it do?
I googled it and I could not figure out what it is. That could very well be what is causing my problems, but I have no idea what this valve or regulator would look like or even where it is at. I left my Haynes Auto Repair Manual down home, 5 hrs away!
Thanks!
The IACV regulates idle speed, raising and lowering it as needed. It does this by opening and closing a "trim" valve to allow more or less airflow into the intake manifold when the throttle is closed.
The adjustment we make on the IACV is for setting the "base idle". By unplugging the TPS we tell the ECU to completely close the trim valve in the IACV. When this happens, the idle airflow comes completely from a needle valve - the one you can adjust when you turn the screw on the IACV body.
If everything in the fuel and intake system is operating properly, the idle speed will not be able to drop below this setting. A few things can cause the base idle speed to go out of adjustment.
First, the needle valve can become clogged with dirt or carbon, reducing or completely blocking off airflow through the needle valve. This would reduce the airflow through the needle valve and cause the ECU to rely partially or fully on the opening of the trim valve in the IACV to maintain target idle. This would mean that the idle could possibly fall below 750 before the ECU could intervene.
Second, the trim valve within the IACV could be rendered partially or totally inoperable, either through blockage or failure. If this valve is blocked open, idle speed would be high unless the needle valve's opening was reduced to compensate. The result of this may be the inability for the ECU to compensate for all idle conditions - base idle would be set for Y percent trim valve opening, leaving only X-Y percent of the operating range of the trim valve for ECU adjustment. If the trim valve is not blocked open but the passage to this valve is partially clogged, it would require the ECU to open the valve farther than normal to allow a given amount of airflow to pass. This would also reduce the amount of compensation the ECU can apply to idle speed.
To sum it up, there are two idle speed adjustments to control idle on our cars. First is the manually adjusted base idle setting, which determines the minimum airflow through the IACV (and minimum warm-idle speed). Second is the ECU's control over the "trim" valve within the IACV, which compensates for hot and cold idle and engine loading (power steering and A/C operation).
Now, there is one other factor in this equation, the IACV-Air Regulator. This valve is in parallel with the IACV-AAC valve. This valve is what supposedly makes the car idle fast when the it's cold. The FSM gives the following description of the IACV-Air Regulator.
"The IACV-air regulator provides an air by-pass when the engine is cold for a fast idle during warm up. A bimetal, heater and rotary shutter are built into the IACV-air regulator. When the bimetal temperature is low, the air by-pass port opens. As the engine starts and electric current flows through the heater, the bimetal begins to turn the shutter to close the by-pass port. The air passage remains closed until the engine stops and the bimetal temperature drops."
Here is the diagram:
Note the IACV-AAC valve is under the intake plenum, back by the fire wall. you have to remove the intake plenum to get to it.
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ive got a 1996 pathfinder SE 4x4.
when i am sitting with my engine idling it oscilates about 300rpm. im just wondering why it does this and how the heck can i fix it.
also, my odometer stopped counting at 128k miles. wondering how to fix this aswell.
could be many things. Try checking all of your vaccum lines first to see if they are cracked, frayed on the ends or loose.
up and down engine can also be caused by:
air filter filthy
MAF sensor
EGR valve stuck/bad
clogged PCV
clogged fuel filter
engine temp sensor
IACV-ACC valve
O2 sensors
also check the wires and connectors on these parts for loose/corroded where applicable.
As to the odometer, does the speedometer work? If it does still work then mot likely you are looking at needing a new cluster meter.
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Here is the set up:
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Here is the parts diagram. This one is for the Z24. Teh VG30 is nearly similar. Couldnt tell exaclty if you had a 2.4 or 3.0 from the photos. Looked like a 2.4.
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Yep. 700-750 here...
B
650-700
750 i believe is spec
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would that relay be mounted on the firewall on the passenger side??
Yes. right next to the wiper motor.
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I have an '05 Pathfinder SE. Information's suprisingly scarce. I found one sight that mentioned the lug pattern being 6x 5.5" and that sounds kind of fishy as it should be measured in metric. What's the lug pattern?
Also, I have the stock alloys. Can anyone tell me the offset of these wheels? I'm assuming that if the offset goes out a bit, there's not going to be any problems with rubbing as their should be enough clearance with the stock height?
In the US wheels are still done and discussed in inches.
If you have an 05 pathy, the wheels should be 16x7 or 17x7.5. There were 5 and 6 spoke versions made by Alcoa and Enkei for Nissan.
All the R51 Pathfinders are 6 lug wheels and hubs.
The lug pattern is 6 x 5.5. This means there are 6 lugs on the hub and there is a 5.5 inch space in the middle for the spindle.
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Start with a complete fluid flush. If there's air in the system, or a lot of moisture it will affect them a lot.
Also make sure your rear brakes are adjusted properly
If that all checks out and you still have a problem, then you may have a problem with the master cylinder.
SECONDED
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I made an appointment with the dealer..which i was going to do originally but they are twice the distance....anyway they said they doubt it was a clog too. Probably a switch cycling the compressor on and off.
Thanks for all the help for now...we will see what they say. May still fix it myself but will let them troubleshoot it first.
Thanks
Your Pathfinder AC system has 3 important sensors designed to shut the AC compressor off if it thinks there is a problem. This is done to protect the compressor and other parts of the AC system. The downside is that if one of these sensors is bad or going out or has a corroded/loose connection, the system thinks there is a fault and the system shuts down.
You have a temperature sensor on the compressor, on the top towards the back. If it senses the compressor is too hot or cold it will not let the compressor engage or turn it off.
There is a Pressure switch on the liquid tank could be bad, causing the system to shut down when the system has too much or too little freon.
There is also the tHermo sensor in the evaporator case that is designed to detact if the evaporator is freezing up.
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According to the dealer, the fan clutches are starting to fail on all the older nissans, and they've started to stock new ones in all the parts departments.
There alot of parts starting to fail on old vehicles.......
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Hi every one,My truck usualy idles about 900 RPM but some times (specialy when the weather is hot) it will idle at about 1300 RPM I have checked all the vacum hoses and replased the ones that didn't look to good hoping to eliminate the problem but it keeps doing the same thing. Any help will be greatly apreciated.
Does it do this when the AC is on or has been on?
Does it do this when the AC is not on and hasnt been on?
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And I have a question...
It was a bit of a pain in the ass day, since I had to leave twice on the bike to get the parts because the parts guy gave me the wrong pieces to change the tranny fluid and filter.
Anyways,
So I drained it as per the manual says in the maintenance section, a la the one drain bolt in the pan. I'm not sure how much exactly came out but somewhere close to 8L.
I then measured approx. 8.5L (I spilled a little bit and my measuring cup turned on once) so give or take probably 300 mL and dumped it through the measuring tube. I then started the truck, let it sit for 30 seconds, and checked fluid levels which are way more full than the top of the hot reading.
What I'm worried about is reading up now I see mention of the torque convertor, which I didn't separately drain, unless it's done with the main tranny pan drain bolt. I can't even find instructions in the maintenance part of the manual on how to do this? Please tell me that the one big drain in the pan is the only one.
Also...to fine tune the amount of fluid I am guessing I am going to have to take a bit out. Anyone have a refined technique for this, other than dropping the same drain bolt for a couple seconds? If I have a bit too much in the tranny, what does this do and will it be bad to leave a bit extra in?
Oh, and I didn't change the transfer fluid? Will this fluid mix with the tranny fluid? The front transfer fluid isn't the torque convertor, right ?! So I'll need 8.5L for the tranny and 2.2L for the transfer fluid, not 8.5L total ?
Cheers!
Dont overfill your transmission. Best to under fill it and then top it off. If you are over let a little out at the drain plug and then get it right at the filler.
Transfer fluid is seperated from the transmission fluid.
The touque converter is not the transfer case. The torgue concerter holds fluid, so when you drain and refill, you are only replacing about 1/2 to 1/3 of the total amount of fluid the transmission holds.
The only drain point for the transmission is the drain hole you used.
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Figures the gates of hell would have Starshmucks
I read the other day that they are closing some 400 stores in Texas.
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Sounds like you nailed the culprit down.
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i dunno bout you guys, but all over my quiet lil town we have those "speed signs" where yer drivin along and there is a speed monitor at the side of the road telling you how fast yer going? that's how i originally checked mini (also by another vehicle being ahead of me and via walkie talkie telling me what speeds we were at) and with king, to check (after 7" of lift &33's) his was all dialed in, i used the same speed sign to check his was accurate. it is SPOT ON.
don't trust the speed signs on highways tho...... they're FAR from accurate
Funny....on my way home they had one of these up and I thought of your post!
So I now know that my speedometer is correct from 40-45 MPH.
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Idles like a 2 cycle and puffs black smoke
Kills sometimes when put in reverse
RPMs drop and raise back up
Kills occasionaly while I am driving
Has difficulty (struggles) to shift at times
My problem seems to be associated with hot humid days, on cooler days it seems to run much better.
based on these quoted points I vote IVAC-ACC Valve and/or regulator.
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What's the differences in the transmissions? THey're all RE4R01A are they not? I am not doubting you, just don't quite understand what the differences would be, and if so, why they'd have the same part number.
Yes, they are all model RE4R01A.
But like an engine, there are differences, changes and refinements as the years progress.
For a nice analogy: an ‘91 WD-21 and a ‘95 WD-21 are both model WD-21. They even look similar on the outside. Get inside and they are very different. Same with the transmissions. There are differences in the inside.
Take a look at this screenshot. It shows the part numbers for a R50 transmission and T-case assembly. It shows the 8 part numbers, the application dates by production and so forth.
Now, look at choice 3 and 4 and choice 5 and 6. These are completely identical assemblies but have different part numbers. How do I know this?
#3 is 31000-4EX75. #4 is almost entirely the same. Just one number higher.
This means that there is some part in them that changed manufacturer/supplier for some reason. (reason is quality or price typically) Whenever a part changes, in any way, it gets a new part number from Nissan. So, if some genius engineer decided a screw should be painted blue for model year X, the new blue painted screw gets a new part number and thus the assembly it goes on would change.
SO...
If I was to try to pick choice 3, I can tell you it will supercede to the next choice.
Now, look at choice 1 and choice 7. Two years difference in when they were used. If you look at the part numbers they are much more different. That means inside there are some changes.
Now, could you just pick any of these choices and throw them in your R50 and never notice the difference? Probably.
Would I recommend it?
No, as you never know what other changes they made to the ECU and especially the AT Control Module as well
I hope this helps some.
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Remanufactured alternator.
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idle at 330rpm's is way too low.. it should be double that or so.
Yeah, i think its 750 rpm.
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that article cracks me up all the time.
I go look at it from time to time because it is always changing.
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omg i think i just puked. WTF.
i'll give him $1500 and sell it to some dumbass down here for $15k........ *gags again*I dont care for that candy stuff.
To each their own I guess.
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They will also probably hook your lines up to a drain machine.
If they are high tech.
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After Looking closer at it while driving to work(Sitting in Traffic), I decided im going to go through the right side of the instrument panel.
One whole with gromet and and all wires wraped up neatly.
Im going to do it next week on my day off I'll post pics.
yes please post pics!
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The ideas in my head all point to dealer only parts.
I can probably beat the price your local dealer will charge. If you order from me it will be less $$ but take a few days to ship it. It is up to you.
I am not helping people just to make $$
I am helping people because they have helped me in the past.
AC heating problems/purple liquid
in 90-95 WD21 Pathfinders
Posted
the die used to detect freon leaks is purple and wil make a purple liquid where there is a leak.....it could be leaking down from the condensor to the bottom.