My 90se auto(178k)has had about a year of rough idle, smell of gasoline at startup, poor milage, hesitation & periodic check engine lights. All symptops that are way too common with our cars on this board. One day I happen to take my dad's lexus ls400 to a lexus/infiniti specialist here in san diego last month. I just found them on the internet, and they told me that they would diagnose the check engine that comes up on his lexus free of charge. I did take it in, and they did print out that the EGR valve blah blah blah...$75 bucks later the lexus is again a beast on the road. I did tell the mechanic that I have thee above problems with my Maxima and that I have not taken it to a Nissan dealer but a slew of cheap-labor mechanics that have had me replace my Air Flow Sensor, clean out Throttle body, PCV Valve, Distributor cap, Spark plugs/wires, Thermostat. To make a long story longer, he said I should bring my Maxima in and that his computer should read my Check Engine codes fine. Did that last week. He diagnosed while I watched, 3 Fuel Injectors returned bad signals. There was also a visible leak from an O-ring. He also found a Front Crank Seal to be leaking a little. He asked me if I had replaced Timing Belt/Water pump recently...and I had done so in March at one of the quick and dirty mechanics. He just told me to keep an eye on oil level weekly until I decide to replace that seal. The Check Engine was due to the Fuel Injectors and he recommended I swap out all 6 + new gaskets, and some kinda harness. $420 for after-market injectors and like $50 for the harness/gaskets. Total damage $700 and left the car 3pm Thursday and picked it up 3pm Friday. Well so far I've driven the thing real hard/cold and abusive to try to provoke the symptoms....and nothing! the Maxima runs like it did the day I bought it (~60k)

 

....In the last month my Maxima had got significantly worse. In the mornings, my RPM(at a red light) would bounce from 700-like 300!. Very disturbing and embarrassing...I would have to switch to neutral and rev to keep it alive. Things would be cool once on the highway.
I would hit 75mph @ 2500rpms (is that normal?). I would also get like 260miles on a full tank of 80% highway driving.

About the front Crank Seal replacement...the Lexus/Infiniti tech actually told me I might be better off taking that back to the same mechanic who did the timing belt/water pump to maybe bark at him a bit for overlooking this. In your experiences with that, how much should such a replacement job cost me?

Thanks...this is my first post on these boards, I've always just been a lurker until now. I really appreciate and admire your(collective) knowledge/opinions about cars.

 

That sounds sort of like the problems that I've just started having with my max; the CEL comes on and the car begins to idle rough, stutter under light acceleration, and put-put from the exhaust. Could this be an injector problem?

 

I had the sever sputtering from the exhaust...and the rear passenger-side seat would warm up from the bottom after a long trip. I assumed the warming was from an exhaust leak or something. I have had my car back for 2 days now since the repairs and I still sense *very slight* sputtering. I have yet to notice that heat/moisture under the rear seat. My rough Idle problem is definitely gone(i've been testing my car for the last 2 days straight)and no signs of it. I still notice a slight smell of gasoline...it could be in my head. All the fumes i've inhaled with this Maxima could be getting to me. If this minimal sputtering is it, then i'll gladly live with it.

 

I also notice from time to time, the stuff you're explaining.

When I have just the air on, not A/C, but just air set at 'cold' temp blowing, I can smell a little bit of fuel. Whenever I have friends in the car, I ask them if they smell it too, but they say they hardly smell anything... they don't really notice it... so it might be in my head too then, but I really DO smell it!

I also get bad mileage, but I use about 60% to 70% highway and I can hit 300 pretty easy.

At 75mph, I get about what seems to be 2300 to 2400 rpm.

I know these are just my comparisons, and there's no real advice in my post... but I thought it might help... somehow, somewhere..over the rainnnn bowww.. opps there's my singing going crazy again.