Problem with my Pathfinder

[RiyekoL]

Alrighty ive looked everywhere online, ive looked in some maintenance books at the stores and asked some folks at some local auto parts stores, and I have found NO information that helps me at all.
The local mechanics here wont even give me an idea of whats wrong with it, unless I pay something.. I understand everyone needs to get paid, but if I can do a job myself (even as a woman), by goodness im going to do it!

Here is my problem.
Truck (yes I know its an SUV, but Leo is a TRUCK!) has been a wonderful asset to my family.
Love taking it places and doing things, but lately the problem we noticed on the test drive has gotten worse.
It lags.
I dont know how else to explain it. When we first bought it, the problem was right after it had been sitting for two years in someones garage and we thought, "oh its just because it needs its engine "cleaned" out by driving it a bit".
Well, that fixed it for about six months, and now, its gotten worse.

Sometimes it doesnt do it, sometimes it does it all over the place.
I will start it up, give it a few minutes to let it warm up and then drive normally.
Sometimes it runs just great, purrs like the kitten it is, and then sometimes its like im battling the den full of lions.
I am driving, accelerating down the road, and then suddenly, it looses power, the RPMs drop, and it "lags" out.
It doesnt stop running, just seems like its being choked to death.
Ive used every word from choke to lag to try and find out whats going on, but nothing has helped.
Ive gotten some ideas, but I would like to know if I can do this myself without taking it to the mechanics.

My husband and I discussed this and thought, because its an old car (my Honda had the same problem), we put some HEET into it, and it ran fine for about a couple days, then it started up again.
My husband thought it might be dirty spark plugs, but the local dealer we bought it from said he had changed that all out, we checked and they are clean and nasty free.
I checked the air filter, wonderfully clean (for an air filter lol).
Ive changed the oil, ive checked the battery and the connections (since its horn was broken we hooked up our own... yep, button the dash lol), and everything is fine.
Ive even used the online advice to check for air leaks or leaks of that sort anywhere on any of the hoses and still.. nothing.

Does anyone have any idea what the heck is wrong with my Leo?
Any advice, tips, tricks, suggestions... are most MOST welcome.
Its getting to be winter and this is my first 4WD truck. Id like to be able to play with it just once before I have to go back to being an adult and a mom (and im not going to go do donuts, ill probably just slide around on the ice a bit).
Anyway, any help is really appreciated.
Thank you in advance, and sorry about the wall of text, im long winded.

[Towncivilian]

Try changing the fuel filter. There is a great how-to at the stickied thread at the top of this subforum.

Welcome to NICO!

[04pathse]

May want to try cleaning the MAFS (Mass Air Flow Sensor), and then reset the ECU by disconnecting the battery for a few minutes.

[mthatch]

I had an issue like this on another vehicle. The crank shaft positioning sensor was going out. I would be driving and I would suddenly loose power. If I gave it heavy throttle, the engine would bog out and then rev back up and then run normal. Sometimes it would just feel like it was going to die and then would quickly rev back up and surge forward. Just a thought. Have you ran any diagnostics on your truck? There may be some residual codes on your computer that may give you an indication of whats going on. AutoZone does free OBDII scans...

[NismoPick]

This...

Just a thought. Have you ran any diagnostics on your truck? There may be some residual codes on your computer that may give you an indication of whats going on. AutoZone does free OBDII scans...

Except 95 wasn't OBDII.

Diagnostic process for pre-96: http://www.nissanpathfinders.net/forum/ ... athfinder/

[mthatch]

I didn't realise it was was a 95, but I'd definitely check the ECU for errors.

[NismoPick]

^^^ Just going off the car in her profile. She didn't mention the year.

[southpontotoc31]

Clean the MAF sensor like mentioned above. I had the same issue for a few months and could not figure out what was wrong with it. Took me less than two minutes to clean it and now my pathfinder runs like new again.