Just a tune up?

[Terra-fied]

I seem to be having an issue with my engine in my 2000 Xterra that the dealership says does'nt exist. It seems that as soon as the engine warms up to operating temperature if I am at a stop then give it a pretty good amount of gas it wants to hesitate a little or the power cuts out breifly. It will also do this if I give it pretty good gas to pass someone. If I don't give it much gas from a stop it does'nt seem to do it. It does'nt seem to do it right when you start it up either. It runs great other than that. Since the dealership says they don't notice anything I am left to wonder if I should start by changing plugs, wires, cap, rotor and fuel injection cleaning or what. I have read that some people have problems with Knock sensors too. I dont even know what that is. I have not had a car do this to me before and I hope how I describe it makes sence. Oh its getting about 270 to 300 miles on a tank of gas to if that helps. I think thats average?

I am open to suggestions, and even more so if someone here thinks they could diagnose it, I am more than willing to meet some where.

Thanks in advance everyone.

[nissandoms47]

no check engine light? I would start out by replacing the air filter, fuel filter, rotor, spark plugs, spark plug wires if they seem worn and the cap if its worn out. also try running a can of seafoam through the engine.

[Terra-fied]

Nope. No check engine light. I have never heard of Seafoam. Can you get that at advanced auto parts?

[Nissanclay]

Check you MAF. Mine was loose and did that then got worse and worse.

[Alpine Spirit]

Small hole in the air intake hose or maybe the hose is about to come loose.

[Ditchfinder]

The mass air flow sensor may have dirt or dust in it. Regular cleaning should be performed, remove it and clean it out using low pressure air. When I say low pressure I mean no more than about 5psi as any more can do damage. I have used computer cleaner," air in a bottle", this does the trick well. If you replace your plugs stay with the NGK'S. I would avoid bosch if possible. your wires are probably fine. A fuel filter would be a good suggestion as well. I use BG 44k fuel cleaner or Techron by Cheveron ,available at wallmart, costs less than the 44k. I would start there. If the problem still persists wait until it is doing it ,then take it to the dealer, and go for a test ride with a tech at the dealer. I work at a dealer and riding with the customer helps provide us with more of an idea of what is going on.Oh and get yourself a factory service manual you will thank yourself later Helms inc.com good luck and welcome.

[ChefTyler]

how in the heck do you get 270-300 miles per tank??? I was getting 250 tops at Sea Level in California when it was brand new!

[Allen Cox]

Sounds like a MAF issue, running lean. That's why you're getting the higher fuel mileage as well. Probably need to see what your 'self-learn' is, where your A/F Alpha is also reading when you're all warmed up. 90%-110% is considered normal and within perameters by Nissan. But you'd need a scan tool to read all that information for an accurate diagnosis. If you can get one, or find a tech that can ride with you, have them look at the MAF voltage when accellerating, along with the rpm too, to give a nice mapping of when the MAF and the rpm's both go haywire at the same time.

Good luck!

[zonianbrat]

I have never used air to clean my MAF. I take the MAF out then use a Q-tip and some Isopropyl Alchohol and wipe the contacts down VERY gently.

[DamnHippie]

From a symptom of hesitation on heavy throttle but fine performance on light throttle, my first thought is fuel filter, especially if it's never been replaced.

I had those exact symptoms last year and I had just replaced the fuel filter a few months earlier, so I discounted it as the cause. It turns out a Nissan dealership in Phoenix that replaced my bad fuel sender reused the old O-ring and it fit so badly that my tank fill with dust and clogged the filter in a few months.

[8th Man]

First thing that came to my head was the fuel filter.

[Terra-fied]

Update:

Ok so I have messed around with it a little bit. I stopped by the parts store and the guy wanted to look at the engine. He said not to do the wires or plugs and that the wires looked pretty new and were some $100 set so they should be fine. I figured since the problem is not there all the time it probably is not a plug or wire thing anyway.

I took out the MAF sensor and cleaned it off with a MAF sensor cleaner. This has not helped either. There really was no change and it looked really clean when I took it out.

I added a can of Seafoam with the last fill up. I dont know how fast that stuff starts working, but a tank will last me a week or more. I only drive 4 miles to work. So can't really say if that is helping yet.

I have not done the fuel filter yet, but have thought about doing it anyway and will probably do it this weekend.


So the problem still exists and I am more confused after last night. I dont usually have a heavy foot, but I was curious if it would be worse or not if I just floored it from a stop and also when already moving. Well when flooring it, it has no problems. Drops down to the lower gear rpms up and put on your seat belt. :eek: Ok maybe a little exageration, but it does'nt happen under heavy acceleration. So making it do it pretty much requires you to give it just enough gas to want to drop to a lower gear, but not enough to make it actually drop down. So light acceleration or heavy acceleration it likes. Just not when you push it to the point where anymore would require it to drop down one gear. :confused:

I know I am not real knowledgable when working on them so I am sorry for the long posts and lack of knowledge. I just want to get her running good so I can get out there and have fun wheelin with you guys. :o

Thanks again everyone!

[Ditchfinder]

I dont know what scan tool nissan uses.? We use one called the HDS its a tablet computer, but I can look at all the data for all the sensors on the car. I believe Nissan has the same setup. As I said get a tech at the dealer to go for a ride with you make the problem happen for them while the scan tool is hooked up. The live data stream should be enough to assist them. There may even be a tempoary code stored. If the car was in the dealer with the same problem and they did not fix it ,and you can prove infact that there is one then they may not charge you another hour.(for the diag that is) I would talk to the same service writer that you scheduled with so you have some history then arange to ride with the lead tech express your concerns but dont get angry it only makes them less willing to help. One other thing that I have seen problems with is our EGR valves it causes a stumble on accel we match the lift sensor voltage to the lift sensor they should match and if they do not then the egr is sticking causing the problem. that may be another culprit. good luck.

[Allen Cox]

If the EGR was sticking, the EGR temp sensor would stay hot and the computer would throw a code.

I'd check for a vacuum leak. Take a can of highly flameable brake cleaner (not joking, has to be able to burn) and spray lightly in small areas at a time on your engine. If the engine revs at all, then concentrate on that area and find the source of your vacuum leak.

[dvdswan]

clean the MAF wires with a Q-tip

[Terra-fied]

Update:

I had to go to the dealership today to get the tie rod replaced since it was supposed to be fixed when I bought the X and they had to order the part. One of thier mechanics actually believed me that there was a problem and said he would check it. Well..... Here is what he found:

http://i104.photobucket.com/albums/m165/GENE77_2006/camerapics002.jpg

One of the spark plug wires was cracked at the boot where it slides on to the plug. It was cracked enough that it would arc to the block when ever it felt like it. I still have the bottom piece of it too somewhere but at least you can see where it was cracked. I must have just totaly missed this when I looked over the wires. Well at least the MAF sensor is clean now and a new air fiter. It should be a happy X now. Thank you everyone for the help and suggestions. Now I just need to get some better tires and I'll be out there hitting trails. :bannana:

Thanks again!

Gene