Ok, i just checked my ecu for ghost codes, nothing, got 0505, so no error. Anyway, my car is still sluggish and gets bad gas MPG. I am wondering if it could be one fo the following:

Compression issues
Carbon buildup issues
Injectors

If you guys can help me that would be great!

And could a bad/dying alternator lead to any of my symptoms? Would that trip a CEL? Just making sure!

Thanks guys!

 

well, my car was acting sluggish wen i first got it and it did horrible on the dyno, i had no codes but people still told me it was the knock sensor. i had a spare one laying around so i changed it and the car felt so much better.

 

all those 3 items stated COULD throw a fault. but might not as well.

best bet is to start off with general maintence. air filter, fuel filter, plugs, inspect for vacuum leaks. Why do you assume the ALT? If you done all these recheck them. You might of not gapped the plugs correctly. might not of installed the filter hose correctly. just double check your work. So aleast you have something to start with.

 

well im assuming you changed you KS ... so if its not that check for the stuff you listed.

 

Maxima5Spd. Ok, well then it still may be my KS. Thank you for that info!

Turtle. Air filter replaced < 1K ago, but I havent done the other three. The reason I assumed my alternator was because of this:

http://forums.maxima.org/showthread.php?t=497936

Thanks guys! Anyone else got some info I can chew on?

 

well, um personally i have a 98 auto and i dont really mash i, i'm a cruiser at under 3k RPM. city wise i get 20-22mpg. And i dont have a problem with my ALT battery or anything like that. But that definally sounds like a ALT issue when your battery light is blinking meaning your car isn't generating enough voltage.

And if you wondering, i've done plugs and a new KS and i still get on average 20mpg. And honestly 20 is dead in the middle of not bad nor not good. When i got my KS in the first week i drove it i just raced it all day long. ended up with 17mpg.

http://www.fueleconomy.gov/feg/noframes/14340.shtml

since you have a friend with a shop. most likely they wont rape you with prices. ask them to give you some injector flush, and pending on what you know how to do try to get all those done.

 

I am not heavy on the pedal either. Generally, I run about 2500rpms or so, I coast to lights in N, dont heavy accelerate, etc...so I am wondering why my gas mileage is so bad.

I am going to take it to my friends shop sometime this week, and have it checked out.

Oh, and the battery light isnt really blinking per se, it is random flickering. The ebrake comes on whenever the batt light comes on also. Its weird, but I still think it is my alt.

Thanks for the info.

 

its your ALT, check the charge of the battery as well. i've seen bad ALT mess up batteries as well.

i'm telling you, your mileage isn't bad. coasting in N doesn't make a diffrence.

 

Alright, well thanks for the info man! I guess I was exagerating a bit...I need a new battery, as mine died on me a few months ago and has been running low since. Guess Ill get a new one with the alt.

 

befor i replaced my knock sensor i got about 26- 29 and i run it hard alot. now i have knock sensor and pr style cai so i figure i get even better now. but im a 98 se 5spd. ive been told the 5spd makes a lot of diff.

 

I wish I was 5 spd...for the fun of it, the performance of it and the fact that it owns auto period...

 

what about humid weather? humid weather has more water in the air, do u think the engine likes watered down air???? just a suggestion..... cuz i noticed that for sure here in chicago lately, sometimes, when its cold and not humid, the car pulls like it broke loose outta hell, other times it like just wants to crash, die, and burn....lol

 

The performance sags any day, any time, and has for the past few months. It was low 80s and low humidity the other day when I tested it, to 60 was 10 secs, 1/4 mile(roughly a 1/4) was 18 secs...

 

when my alt was done the lights would get brighter when i hit the gas. also it made a gay whining noise when the gas pedal was pressed. also when it hadnt been started for a while, it would squeak like i had a bad belt. and the belt was new.