LET ME TELL YOU WHAT THE HECK I JUST WENT THROUGH TO SOLVE THIS PROBLEM!!!!!
THANK GOD FOR THIS BOARD!!! YOU SOLVED IT FOR ME!!!
Okay, after my experience trying to figure this damn thing out, I now know how important it is for everyone to post on boards like this exactly what it is the problem they had and what the fix was. You'll understand why after reading what I ALMOST ended up doing, and luckily, thanks to this board, DIDN'T.
I'm naming names here, too.
I live in Southern California. I bought my 2004 Armada new in early 2005. After having gone through 2 Chevy Suburbans and 1 Ford Explorer, all three having had the same damn transmission problems(can you believe that????) I said, NO WAY WILL I BUY ANOTHER AMERICAN CAR!!! Needing a big SUV, at the time in 2005 I decided on the Armada. Let me tell you! 7 years later and 120k now, I have had NO PROBLEMS and I drive this car to death! Kuddos Nissan!
However, since about 90k miles, I've started to have this hesitation problem under acceleration. It's slowly gotten worse over the last few months, a few times to the point of almost not being able to drive it. I researched to death the cause because the local dealer said since I had the ECM relay changed under recall, it couldn't be that, as many on this site claim that problem to be. Was it the IPDM itself? That didn't make sense since if it were bad, the problem would be far more consistent. And my car never gave off a warning light on the dash. And THAT was the problem I've had for over two months - I swear they don't make mechanics anymore, just guys that read what the computer tells them is wrong. If no computer light is on, then to them, there is nothing wrong.
Well there was something wrong!
Surf City Nissan all but told me the same thing: no light, no problem.
I was on the freeway merging into traffic when I had to punch it to make the merge, the car just starting jerking with litterally NO power. Almost caused an accident because I couldn't gain speed to catch up. So I decided to take it to a local mechanic. I explained the problem in detail and luckily, having driven the car all day, by the time I got to the place it was 'acting' up. The head guy drove it with me. I told him to punch it and BAMM - it did it. Just jerked and hesitated. So, he felt it. But after leaving it with him for the full day the next day, they couldn't find anything.
Why? No light, no problem. Computer said car was just fine.
I started to wonder if it was a transmission problem. It was the way it shifted when you let off the pedal, it seemed to want to shift 'properly' almost as if the hesitation was caused by slipping in the passing gear when you punched it.
I then took it to the most highly recommended tranny guy in Bellflower. He drove it with me in it, had it hesitating like crazy, making me feel at least maybe this guy figured it out. We got back and he looked at me and said, 'it's definitely not your tranny'.
Great. Now what?
Being right down the street from Cerritos Auto Square, I took it then to Cerritos Nissan, thinking that since it's such a big place, they must have experience with this and would know how to fix it.
They were really cool there in the service department. But being cool and being 'good' are too different things. After having the car all day, the verdict from them was that it was 'definitely' a clogged exhaust pipe that runs right before the cat converter. Because I had to change both out together, it was going to cost - wait for it ----$3300!!! :eek:
I almost said fix it, since trading it in for a new car with new $700 payments wasn't really what I wanted to do. The damn car is in near perfect condition and aside from that problem, runs perfect and has been very well maintained.
This was last week.
So, deciding NOT to want to pay for that repair, I just about came to the conclusion I was going to trade it in. But having some time, I took it back to the local guy - Dr J's in HB, and paid them to tear the exhaust off and look in the pipes and cats. After a few hours of that, the result was --- wait for it --- perfectly clear and clean.
So WTF? Had I just said 'do it' at Cerritos, I would have paid them $3300 for what? Replace something that wasn't broke? Since they had it all day, and were so convinced that was the problem, didn't they even LOOK at what the pipes looked like? They're pretty easy to remove and see.
So my basic thesis is that Cerritos Nissan's service would have lied to me and screwed me out of $3300. So stay away from that place.
But that still left me with the problem. I had decided that last Wed night, (2/22/12) I was just going to bite the bullet and buy a new car. I wasn't about to spend a couple grand just trying to research what the hell is wrong with my car.
Before the wife got home to car shop - was going to buy a new Armada though - I did a new google search for the issue. I googled before 'Nissan Armada hesitation on acceleration' - and came up with the same solutions - IPDM or ECM. But this time I did, 'How to change a Nissan Armada Fuel Pump'.
That led me to this board. The explanation by Armadaof1 was EXACTLY what I was dealing with. Basically fuel pump. So, just today, I went back to Kevin at Dr Js and told him to change the fuel pump. Just got it back this afternoon....
OH MAN! Made perfect sense. No light because a poor performing fuel pump isn't connected to the emissions system. The fuel pump is only $390. $200 labor to put it in. THE CAR DRIVES LIKE NEW! I mean, apparently not only was it preventing me from 'punching' it, it was also dragging the car in normal driving conditions which was subtle enough to not make me really notice. But with this new one, holy cow! It feels like I put a turbo on it. I guess it's just been that long since it's driven 'right'.
Kevin at Dr J said that they found an outstanding 'TSB' on it for 2004-2006s, but since it's not a safety issue, they didn't recal them. Sounds screwy to me, but hey, for $600 and no need for a new car, I'll deal with it. Hey, 7 year old car with 120k miles that drive like new now is worth every penny.
Bottom line (after that long winded diatribe) - if you have hesitation on acceleration in your Titan or Armada, CHANGE THE FUEL PUMP. It's easy and cheap and worth it!
Your ECM relay or IPDM symptoms are completely different. Your car will actually die if those are bad. Or not start at all. That's not a symptom of a bad fuel pump.