aminus21

iTrader: (14)

My engine has not been idling smooth for some time on my 90 GXE Auto. About 6 months ago it was real bad, I changed the cap&rotor+fuel & air filter, and nothing really happend. then I changed the spark plug wires and it got a lot better, but still not perfect. It is still missing but not a lot, so I was almost sure that it was the PCV hose because I found out it was cracked 2 weeks ago so I ordered that and changed that yesterday. I also just put in some NGK V-Powers last weekend, but it is still NOT SMOOTH.. me MAX has 92k and I run 91 Octane, and the T.Belt, Water Pump, and all belts were changed last year (about 20k ago). My gas mileage is ok, I get about 310 w/mixed driving.

The only thing I can think of is the PCV Valve, but I started the car when I took off the hose for replacement, and I could feel the strong Vaccuum.

So I cant think of anything else..You guys got any ideas..

rudeshadow

hey, wow you get way better gas mileage than me i get 230ish with 1/4 tank left. as for your problem. it seems you replaced everything except the fuel injectors, i would try checking to see if they are spraying the correct amount of gas.

Magnifico

being that this is a maxima, and a VG at that, id definitely consider the injectors

Tom

My Maxima had the same problem as you describe and I pretty much went through the same process trying to fix it. It had the problem since I got it at 65K miles, but since the only thing that was affected was the idle, I just continued to drive it.

One thing that I thought was odd was that it idled better with regular than premium.

It continued to run fine for a very long time, but I noticed that it started getting very finicky on gas (it liked to ping on regular under load). So I started upping the gas grade. One day, I gunned it with a tank of premium and pinged. I knew I had a problem.

A couple of days later I started the engine but it ran really rough and had no pick up. So I tested the injectors and 2 of them were out of spec (I think normal was 10-14 ohms)

So I went to Nissan, got two new injectors (blue dotted ones) along with some gaskets & o-rings, and replaced the 2 injectors. Problem finally solved.

I had 146K miles on the car when I replaced two of the injectors. I was surprised I got as many miles as I did on those 2 injectors. Good gas must really help. I only filled this car up with Chevron gasoline.

I have 167K miles now and it continues to idle smooth and runs great! No pings at all under load. I only buy regular now too.

Now I just need to replace the exhaust manifold studs (doh!)

internetautomar

iTrader: (30)

the lower the octane, the easier it is for the gas to "light off"
and I concur that it's probably injectors.

aminus21

iTrader: (14)

All 6 injectors were changed with new ones from Nissan around 5 years ago @ about 55k, but I will check the resistance on them.

internetautomar

iTrader: (30)

I don't know if nissan had done the injector update by then.