Car Trouble Part Two - Multiple Misfire

[IndyMatt]

Alright this is another car trouble thread after reading the original. I have a '99 Nissan Maxima. It has the check engine soon light on and the codes reads as a multiple misfire. A little on the car, it does not have plugwires or a distributer as it has separate coils over every plug. The coils are known to have issues and I have checked them and they are fine.

Here is the situation:

The light is constantly lit but the car idles fine and drives fine until I need to accelerate. If I hard accelerate it hesitates slightly and the light blinks. I have changed the oil and filters religously, including the fuel filter and plugs. Also, when I add Seafoam (a fuel additive/cleaner which boosts the octane) it seems to help but doesn't cure the problem.

This has me stumped, I cannot figure this damn thing out. The car does burn a little oil and has seen a substantial loss in power and fuel economy.

Any ideas?

[Kent]

Plugs the right heat range?

What kind of plugs. Does Nissan come stock with NGK? If so are there Bosche plugs in it? I know in a Honda that can screw things up.

Kent

[Frenchy]

Water in the fuel was what came to my mind!

[ParagonUSMC]

Originally Posted by Kent

Plugs the right heat range?

What kind of plugs. Does Nissan come stock with NGK? If so are there Bosche plugs in it? I know in a Honda that can screw things up.

Kent

I've got a 2000 Nissan Xterra, and it had a similar problem when I bought it. I pulled out the Bosche plugs, and put in NGK Iridiums, and it went away. I did that the same time as I replaced the wires, cap, and rotor, so it could have been any of the above. You don't have those, so I'd lean towards the plugs (as you've already checked the coils).

[IndyMatt]

When I replaced the coils I replaced the plugs with NGK's. I will look at them again, could this be the injectors and/or MAF sensor?

And it was doing this before the plugs were replaced. Someone else suggested the cam/crank sensor.

I am fairly certain it isn't a coil problem as it only misfires under load and I switched all of them around with new and it didn't change anything.

[BuccaneersFan]

It's been my experience that coils can check out fine, but in reality they are not functioning correctly. If you know what cylinder #s are misfiring you can get a new coil and replace the one that is for those cylinders to eliminate the possibility of a bad coil. If you don't have a bad coil just return the coil to the auto parts store.

[Ishpeck]

Leprechauns!

[RBOWWOW]

I toasted individuial injector's twice in my Altima...two different shops said it was because I used fuel additive too often. Nissan uses an injector that is subject to damage if these chemicals are used..also they are not required.
Car would idle fine, then rough, would sputter on acceleration untill you got to about 4,000+ rpm, then it would smooth out. It eventually got to be where it ran rough all the time.
"Factory says:
Due to the introduction of contamination resistant "pintle-less" fuel injectors, Nissan no longer recommends using fuel injector cleaners in vehicles with injectors of this design. Use of fuel injector cleaner on these vehicles, while providing little cleaning benefit, may cause corrosion of the fuel injector coil and eventual failure of the injector. Do not use fuel injector cleaner on the models listed in the chart or subsequent models with "pintle-less" injectors."

I'm working on finding "the list"..

Try asking here: http://www.nissanclub.com/forums/index.php?

[AZXD40]

Timing Belt? just a thought..

[Brickboy240]

You said the CE light is on....have you pulled the codes? That might tell you if you have a sensor that is crapped out.

I know that with our old Ford Explorer (our first...and last Ford!) when the CE light went on and the vehicle started bucking and missing...I thought the tranny was going out or something major, but after scanning, it turned out to be the MAF sensor.

The MAF sensor is usually located on the air intake snorkel. It is an inline piece that has an electrical solenoid part that plugs into your ECU and has to do with emissions. When it goes out...the CE light goes on and your vehicle will miss and sputter like mad. Ours did! My dad had the MAF sensor crap out in his 02 F-150 and it did the same thing. The MAF sensor has some small wire-like filaments that CAN be cleaned, using electrical parts cleaner and that can SOMETIMES fix the problem. Chances are, its older and the MAF sensor needs ot be replaced entirely. Don't buy an aftermarket cheapo MAF...they're junk...get a Nissan OEM one from a dealer or online. It is an easy thing to replace...even if you're not overly mechanically inclined. CLear the codes and you're back in biz!

If you have tried replacing the plugs and are running the CORRECT plugs, I'd try scanning it for codes and I'll bet its a sensor that has gone south. It might be an 02 sensor, but those usually just trigger the CE light and your mileage drops....no missing or odd running. There are scads of odd sensors on newer cars and if one craps out..they CAN make it run just as you described.

I am betting it is a sensor. Hundreds of thousands of miles on my Volvos over the years has taught me alot about replacing sensors and how a small piece of plastic like that can cause troubles when they go south.

- Brickboy240