2001 Pathy SE new guy

[mikewire]

Hi everyone, I just picked up a 2001 SE a couple of weeks ago and this forum has been a great resource. I'm normally a VW/Audi guy, and this is a nice diversion I thought I would share what I've done so far, throw out some pictures, plus I have a couple of questions:








--Runs and starts great - but it's sluggish above 3K RPM's on WOT.
--Swirl valve appears to be functioning - tested by putting vac to the valve.
--No codes.
--I got just over 200 miles on this tank.

Any suggestions guys??

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

What still bugs me and I will fix:
*Sluggish about 3K RPM's
*~200 miles per tank
*New plugs
*I will clean the MAF this weekend
*Right front mud flap is missing
*Lots of rusty bits, salt roads as it is originally from Michigan - I need to check my front fenders

What I have done:
*Cleaned it up, vac and a wash
*Fixed oil cooler leak
*New ball joints
*New upper sway bar endlinks
*New rear tires to match the front that were new
*Alignment
*Removed an extra exhaust extension over rear axle
*Cleaned and lubed the vent control valve, checked for evap and vac leaks, none present
*Ran some Lucas injector cleaner on one tank

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

[Towncivilian]

Welcome to NICO. Nice clean Pathfinder and an immaculate engine bay!

Inability to accelerate past 3k RPMs is generally indicative of a MAF sensor issue. Try cleaning it with MAF sensor cleaner spray only and see if that helps at all.

You may wish to add the fuel filter to your maintenance list. Also, Lucas injector cleaner is not particularly effective; instead, use a fuel system cleaner containing PEA such as Chevron Techron Fuel System Cleaner (20oz bottle), Gumout Regane, or Redline SI-1. PEA is an effective cleaner which cleans without leaving behind its own deposits as solvent-based cleaners like the myriad cheap "fuel injector cleaners" do.

Your brake fluid looks rather dark, it wouldn't hurt to flush the brake fluid either.

[mikewire]

Welcome to NICO. Nice clean Pathfinder and an immaculate engine bay!

Inability to accelerate past 3k RPMs is generally indicative of a MAF sensor issue. Try cleaning it with MAF sensor cleaner spray only and see if that helps at all.

Good to know - I have some MAF cleaner and I'll clean it today.

You may wish to add the fuel filter to your maintenance list. Also, Lucas injector cleaner is not particularly effective; instead, use a fuel system cleaner containing PEA such as Chevron Techron Fuel System Cleaner (20oz bottle), Gumout Regane, or Redline SI-1. PEA is an effective cleaner which cleans without leaving behind its own deposits as solvent-based cleaners like the myriad cheap "fuel injector cleaners" do.

Very interesting...I hadn't heard of that until today. I think I can pick up some Techron here locally.

Your brake fluid looks rather dark, it wouldn't hurt to flush the brake fluid either.

Yeah I think that's in order for sure. Does Nissan use a specific DOT-4 fluid, or is there a specific brand I should pick up?

[Towncivilian]

Any DOT3 or DOT4 fluid will work fine. Be sure to follow the proper bleed order:

Load sensing valve (4WD models only; it is above the rear differential)
Left rear brake
Right rear brake
Left front brake
Right front brake

Good luck with the MAF sensor cleaning, I hope it'll solve your issue!

[mikewire]

MAF was cleaned with some MAF cleaner. It made some difference, but not much.

To clarify, the motor will accelerate about 3K RPM's BUT it's like all the power is gone. Will a bad MAF cause the motor to not accelerate over 3K, or just cause it to have lousy performance like I am getting?

Still getting the P0455 DTC when I go WOT. I pulled and lubed up the VCV last week, thought it would help/fix but it didn't. Any relation to the issue with performace and the swirl valve?

I also put in some Techron as advised

[mikewire]

Better MPG this tank, about 270. Not great, but not bad either. Thought I should change the plugs since I don't know when the PO changed them. Did the work and whoa, um, well...a picture is worth a 1000 words. New vs. Old:



It now drives better, and this should be better for fuel consumption. Acceleration is still not very good at 60+ MPH.

Still not sure if the acceleration issue is a real problem or not, or if it's just because it's an SUV. I'm almost contemplating taking to the dealer for warranty work and a scan. Will the nissan ODBII scanner reveal more codes that my ODBII scanner at home??

[saveth]

Since its a 2001 I would check each coil pack. You test it by unplugging them one at a time and if it stumbles then you know that one is still good. Plug it back in and try another one. It should only take a couple minutes to check all 6.

[Towncivilian]

Generic ODBII code readers can only read engine codes, not ABS/airbag/transmission/4WD codes, generally. But if the only light in your dash is the "service engine soon" light, a generic code reader or having the codes read at an auto parts store will work fine.

Change the fuel filter if you haven't yet, it should help with acceleration at higher speeds. I am willing to bet the fuel filter is original based on the old spark plugs.

[mikewire]

Good to know. I thought I may not be getting the proper engine codes due it not being a Nissan Consult. Right now I have zero codes, no DTC light, but still have the weak acceleration. Not sure what else it could be, and honestly after seeing the plugs in such bad condition, I thought new ones would fix the issue.

If I had a bad or failing coilpack, would it throw a code?

I know the PO changed the fuel filter recently, but I will get a new one and change it myself.

*EDIT: I'll get a video of the acceleration and post it up. You guys can tell me if I'm crazy or not

[4xq]

I'll throw out a couple of ideas - they may or may not help.

Take a look at adjusting the slack out of the throttle cable. This is both to be sure the throttle body is actually opening 100%, but also for better driveability. Taking the slack out of the throttle cable gives the truck a more responsive feel when you hit the gas pedal. After adjustment, you should be able to read the TPS % at full throttle with a good scan tool. Obviously, you want to see 100%. Just because the throttle plate is actually open all the way when you mash the gas pedal doesn't mean the TPS is telling the computer 100%.

Leave a bit of slack in the cable so you don't accidently affect the idle.

After you adjust the throttle cable, be careful engaging the cruise control the next time - it will need to relearn settings. You can expect it to try and accelerate at first, then it should back off.

Another thing to check at some point is total timing advance. You should also be able to do that with a good scan tool. I have not looked, but I imagine there are some specs in the shop manual.

Pretty good looking truck!

[mikewire]

Actually, I'm fairly certain I just fixed the problem. After looking into the swirl valve problems, I realized I was looking at the power valve, and didn't realize I was totally overlooking the swirl valve linkage.

I went out just about an hour ago and pulled the engine cover off and spotted the swirl valve linkage right down in the center lower part of the intake. This Pathfinder was originally driven in salty Michigan, so the linkages were a bit rust coated and wouldn't move freely. I sprayed the linkages with PB Blaster and WD40 and worked them back and forth with a long flat blade screwdriver.

Once it moved fairly easily with the screwdriver, I took it for a spin, and hot damn! It now will accelerate and rev to almost redline, and pushes from 60mph to 80mph quickly. Before, like I explained earlier it was topping out at maybe 5k RPMs and had no power about 60mph.

So I'm almost certain that was my issue...thanks guys for all the suggestions

[Domenico]

Actually, I'm fairly certain I just fixed the problem. After looking into the swirl valve problems, I realized I was looking at the power valve, and didn't realize I was totally overlooking the swirl valve linkage.

I went out just about an hour ago and pulled the engine cover off and spotted the swirl valve linkage right down in the center lower part of the intake. This Pathfinder was originally driven in salty Michigan, so the linkages were a bit rust coated and wouldn't move freely. I sprayed the linkages with PB Blaster and WD40 and worked them back and forth with a long flat blade screwdriver.

Once it moved fairly easily with the screwdriver, I took it for a spin, and hot damn! It now will accelerate and rev to almost redline, and pushes from 60mph to 80mph quickly. Before, like I explained earlier it was topping out at maybe 5k RPMs and had no power about 60mph.

So I'm almost certain that was my issue...thanks guys for all the suggestions

do you have any pics on this.. im having the same problem as you explained.. or can u explain exactly wat i need to do..thanks

[mikewire]

do you have any pics on this.. im having the same problem as you explained.. or can u explain exactly wat i need to do..thanks

Boy, I don't have any pictures and it really be hard to get any because the area is so tight it would be hard to capture anything useable. If you take a look at the service manuals they will describe and break down the area in better detail.

Look for a couple of linkages in the center front of the motor, below all the vacuum lines. You'll need a flashlight for sure. I used a socket extension and a flat screwdriver to move the linkages back and forth until they moved freely.

I'll see if I can get anything with my camera, but can't promise they will be good for anything.

[00pathyse]

Did the vg33 engine have a swirl valve?

[Towncivilian]

No.

[Domenico]

ok i found it and put wd40 and moved all the links but i still do have that much power after 3000 rpms

[mikewire]

I would verify vacuum on the lines going to the actuator. It's possible the vac lines have been swapped around out of order, or possibly the one line going to the swirl valve actuator is split, plugged, or broken. You'll need a vac tool like a MityVac and some time to test each one, take your time as you go through each line and follow them from source to destination.

When you apply vacuum to the line that goes to the actuator you should see the linkages move and the swirl valve will open.

The service manual does a decent job of showing where each line goes, but you can trace them by had as well. Luckily they are right in front.