Rough Idle/Hesitates off line **Solved, Finally!!**
 

This is my third Maxima (too bad I can only afford them with many miles!).

I have a 94, auto. Bought it from my older brother (got to love family discounts). I have had it for two years now.

About three months ago the following symptoms appeared:

- Only after car warms up
- Rough idle, down to 400 and fluctuating up to 850.
- Almost stalls at idle
- Rough idle less noticeable in N or P
- Off the line, the car would hesitate and jerk until at about 10 m.ph.
- Going uphill, the previous problem would be worse
- If going on a straight away and giving a slight amount of gas, the car
would "burp" and jerk, until more gas was given
- Car squeals when first turned on and in idle, until warmed up

I took the car to a local mechanic, who could not recreate the problem. Very frustrating. Then I realized the problems only occur after the car is warmed up, so the mechanic could not recreate the problems unless the car was warm.

It runs fine on the highway at high speeds, aside from the burping. No check engine light ever came on.

Took it to a dealership who said it needed new ignition coils, o2 sensor, coolant sensor/connector, fuel filter. $1700 dollars. My brother felt bad as he sold me the car and paid for all the repairs without my knowledge. He took my car when I was out of town, had the work performed and it was ready when I got home. I was elated.

Bad news. Car still has problems. It runs a lot better, but the idle is still rough and the car still has some acceleration problems. I took it back to the dealership who said they could not pin point the problem, but could be bad fuel injectors. I am glad I did not pay for the work and I will not have this dealership do anymore work as the car still has the same general problems, even though it does drive better.

Could fuel injectors be the problem? Car runs fine when cold and the rough idle and hesitation off the line and burping when giving a little gas only happens after the car has warmed up?

I am taking it to an independent shop soon, but I would love your comments. Thanks.



edit:
Problem Solved!!
From a referral from this site my car was introduced to a great mechanic. He was also stumped so he called in a specialist. The specialist used his computer to check every sensor, every injector and every coil. No problems found. They were about ready to give up when he said, "let's just take a look at the coils one more time."

The coils were fine as they were just replaced by the stealership. However, this model of car, for some reason, the rubber boots that the coils sit in are shipped separate from the coils themselves. The stealership did not replace the rubber boots when they replaced the coils! The rubber boots were cracked!! Some electrical tape and some praying later, the car works fine. I ordered new boots from pinnacle Nissan for only $4 a piece. $12 total to fix my car after it had new o2 sensor, coolant sensor, fuel injectors, new vacuum lines, cleaning the IAC, throttle body and much heartache. $12!!!! Are you kidding me?

The moral? Well, find a good mechanic who does the job right. No $#(^ right? Also, if you have my model car and you replace the coils, make sure to replace the rubber boots as well, since they are shipped separately. Life is good once again. At least all that other stuff is now knew and the car runs like a champ with all the work. I can not wait to see how it runs with new rubber boots instead of electrical tape :lolrun:

might want to do a tune-up. things like fresh tranny fluid, new air filter, clean out the thottle body, spark plugs, check the belts (the squealing). all these things can contribute. i had similar problems when i first got my max and i did a complete tune-up. it ran great after but i can't say if it was one thing or another or just a combination of everything.

Knock sensor maybe? :gotme:

Thanks for the quick responses. I forgot to mention a few things. Before the problems started, about 4 months ago, I had a complete tune up from the dealership:

New Plugs
Transmission flush
Coolant flush
Fuel injector cleaning / Throttle body cleaning
New fuel filter
Timing reset

I have always taken pride in keeping my cars tuned up. Then, only a month later, my brother had all the other work done. Problems still persists...

the fuel injector cleaning may have damaged the injectors.
How many coils did they replace?

All six coils were replaced. I am hoping the dealership did not damage the injectors when they were cleaned.

Also, could an injector problem occur only when the car is warm?

possibly, but not terribly likely.

ok...sorry for asking u to repeat urself but is this all that has been done so far:

New Plugs
Transmission flush
Coolant flush
Fuel injector cleaning / Throttle body cleaning
New fuel filter
Timing reset
new ignition coils
o2 sensor
coolant sensor/connector
fuel filter

and the stumbling/stalling onle happens while at idle and after warm up. at any driving speed, there is no concern

is this all correct?

if so i would look into cleaning out the IAC - it's the only thing left that i could think of whose operation is speed and temp dependent

I have the EXACT same problem as you. Been that way for about 3,000 miles. I always assumed it was a clogged injector, but if you figure it out, I'd be glad to know the solution.

Right now, I have to work on a driver window regulator that snapped.

-Jeff

I have the same problems too....

And i know its the injector wires, give your plugs a wiggle with the car in D and the handbrake up firm and you'll notice a change. i also have a prob with my ignition wires which have a different sort of hesitation, one sometimes sparks onto the engine a little gaf tape stopped that till i get new ones.

i've got new injector wires but just need time to put them in
anyone done this before?

Where do you get the injector wires?

My car drops to very low rpm when sitting at the light for 10 15 seconds. Wonder what is causing this.

Had the same problem with my 92SE. The most likely cause is the Throttle Position Sensor (TPS). I have access to a shop computer, scanned for codes, and that's what came out. After I changed the part out (it's a little black plastic rectangle on the throttle body) the engine idles smoothly at the proper RPM, and I get no more hesitation on starts.:mardi:

The part is not cheap though, I got an aftermarket one for $130, but may run higher depending on year. Apparently the '93-'94 ones are around $400.

You can change the part yourself in about five minutes, but the only downside is you need the shop computer to adjust it properly, and the adjustments MUST be done to factory spec, or you'll have more problems.

mines kinda doin the same, except it does it when cold or warm and can b felt on occasion up to about 35 or 40 mph, does it worse when stopped at a red light or backing up or pretty much netime at idle or low rpm, almost is unheard of when going faster than 50 or 60 and at or around 2000 rpm. what u think my problem could be?

Did yours also have difficulty accelerating / climbing hills ?

-Jeff

And the solution is? FUEL INJECTORS. Had very similar if not exact problems everybody in the post has. The reason you don't have problems when it's cold it because your iacv maintains 1500 rpm until it warms up and when it is warm (750 rpm) your problem appears. Mine was an injector leaking thru and I also had the infamous "putt putt" sound in the exhaust which wasn't that noticable at first be became quite apparent as time went on. I did all the tune ups and since I replaced injectors, All problems disappeared. No more hesitation or rough idle. Hope this helps.

[QUOTE=dude88888]And the solution is? FUEL INJECTORS. QUOTE]

could this be my problem too? mine does is when its cold also, does it the worse right when cranked up as a matter of fact. one thing i 4got to put in my above post is that u can hear the skipping at all times when hot, cold, idle or accelorating, im hopin it would b somethin smaller like a spark plug but the more feedback i get about these problems the more im thinkin its a injector :slant: , also wat is a good way to confirm if it is an injector or not?

It definitely could be your problem. When fuel injector issues first cropped their nasty heads on my 89 GXE, the car would run fine after the first start in the morning, then after it got warmed up during driving, an injector would start missing. It would keep missing until the engine cooled off. Stopping/starting the motor would not fix it, but usually the next morning after sitting overnight it would work a bit longer. I have a theory that either the coils expanded from heat and lost conductivity, and that the connection with the terminals somehow moved around because of the heat and stopped conducting.

The missing got worse quickly (IE over a week or two...), and eventually did it even when cold. I measured the resistance of the injector coils, and found a couple of them very high (near infinite resistance, or open circuit.) You can test this yourself on most of the injectors (at least on a VG motor... maybe not yours if not a VG) without needing to remove a whole lot of stuff (like intake manifold) if you are careful and remove the metal wire clip (be careful not to loose it.) Then touch a multimeter to the two terminals.

Check out your wiring to see if any of the wiring rubber boots are torn. If they are, I believe it can let in air and water intot he electrical contacts and let them tarnish. Don't overlook the possibility that your injector problems could be due to tarnished terminals.

I got a good used set of injectors recently, that had some badly tarnished terminals. At first, they would not fire, and came up with infinite resistnace on the multimeter, no matter how much twiddling with the testing probe. Measure the front of one terminal and the back side of another. If you don't get a reading very near 0 ohms, it's because of excessive corrosion on the terminal. I made a scraping tool out of a piece of welding rod and after scraping those corroded terminals down to shiney bare copper. After scraping, they conducted very easily, and with very low resistnace. It's amazing how much of an insulator that copper oxide corrosion can be. And now, they are working quite happily on my car, even though I only scraped a couple that were the worst. I will probably go ahead and scrape the rest I can easily get to when time permits. I installed all of the connectors with plenty of dielectric grease on the terminals first, to try and get all the air out of there so future corrosion doesn't happen. Also may help keep out water from getting in there (due to a few torn injector connector rubber boots.):ben:

My car has the same symptons. I actually took out the timing belt and put it all back in figuring I might have screwed up the timing belt installation. I tried the cleaning and although the resistance went down a tiny bit (2ohms) the putt putt sound continues. I cleaned out the IACV, the EGR and replaced all vacum lines. Also changed all spark plugs and put in new wires as well. I guess it is the injector after all. Would the orignial poster please let us know.

Thanks

[QUOTE=mszilves

You can change the part yourself in about five minutes, but the only downside is you need the shop computer to adjust it properly, and the adjustments MUST be done to factory spec, or you'll have more problems.[/QUOTE]



....i have not tried this yet...but heris a link for adjusting the tps.....if u dont have a access to a shop.....however i have not yet tried it

All right, I have ordered the new injectors, vacuum lines and a pcv valve. All will be here by tuesday and I am having a local shop do the installation on Wednesday. I will let you all know how it turns out! I can only hope, but all fingers point to this solving the problem.

Our 93 SE has a little of the putt putt problem, also noticeable power loss, but mostly high HC at 2500 RPM. We had VTC noise that quit about the time of the power loss. Thought it might be related. Now it sounds like it might be injectors? If anyone really knows please let us know. fitz

a putt putt sound is normally from a misfire.
just disconnect the coils one at a time until you find one (possibly more)cylinder that DOESN'T make any difference in the way it runs

two words: TUNE UP

someone here rides the short bus.

All right. Today I had all six injectors replaced, vacuum lines replaced and new gaskets. Car drove fine home. Took it out 20 min later and is having the same problems. AHHHHH!!!! Now it has new ignition coils, o2 sensor, coolant sensor/connector, fuel filter, fuel injectors, pcv valve and vacuum lines. Not to mention the throttle body and IACV have been cleaned. To make matters worse my key broke off in the car door when I took it out for the second time.

Now I am completely stumped. I am at the point of giving up (not really). It is so frustrating when you can not pin point the problem. I just hope it goes another 2 years. I love my max, but it can be so crazy trying to figure her out.

Have you cleaned out the IACV?

I outlined an easy way to do it a while back, here it goes again. Get a can of throttle body cleaner (not carb cleaner). locate the IACV and the air hose that feeds the IACV, trace that tube back up to the intake stack. While the engine is off, disconnect that hose from the intake stack. Insert the red tube (from the the can of cleaner) into the hose about an inch, then try to reconnect the hose to the intake stack (loosley is fine, but it has to make a good seal). Connect the can of cleaner to the red tube, then start the car, begin to spray short bursts of cleaner, go slowly. Make sure you don't spray cleaner onto the MAFS, that could ignite the cleaner.

Thanks Eric. Yeah, the IACV have been thoroughly cleaned as I mentioned. I just can not figure out what is wrong with the car, even with all the work done to it, it is still having the same problems mentioned in my first post. I am very frustrated.

probably just old. mine does it too. i love this car, but i cant see myself investing more than what i have into it. looks like well have to ride around in laggy cars, haha. im actually going to put some accel 8mm wires on for higher current to the cylinders. anyone done this and did they have success?

The Quest Continues...
 

Well I took my car to one of the best mechanics around based on some good referrals. He had my car for five hours yesterday, did some adjustments, looked around and he could not even find the problem. He said he is going to have to bring in a specialist (appointment tomorrow) to get to the bottom of the problem. I'll let you know..

http://forums.maxima.org/showthread.php?t=465638

Also, thanks to all for your help so far.

Anyone figure out what happened to this car?

Unfortuantly ther are no "specialists" out there, you can go to nissan, where they can hook up the 'consult' diagnostic tool and do a 'power balance test' this will tell which cylinder is not making power. And whether its an injector or an ignition coil.

Have you tested the transistor pack?

Also, our injector o-ring fail, its fairly easy to remove the fuel rails and reseat the injectors with new o-rings. Also check the resistance of the injector coils.

Thanks Eric. Since the car has new all of that it is still a mystery as to the problem.

Problem Solved. Check out the edit of my first post to see solution.