Idling issue... now i got a MIL!
 

Hello all,

First post! I'd love for it to be under better circumstances, but whatever.

The Z has been idling a little rough lately, with the RPMs dropping below 500 occasionally when i depress the clutch. This morning I was driving on the highway, and had to stop at a red light, so I pushed the clutch pedal down and the car stalled. I caulked it up to still being half asleep and maybe pulling the car out of gear a little to quick (not that this would stall the car).

On my way home, there was an accident and the highway was backed up for quite a while. The car was idling for a good 30 min when it started to bog down. RPMs were going from 1000 to 400 - back and forth. It sounded like the radiator fan was attempting to turn on, but it couldn't... then like clockwork - "Service engine soon".

Oil temp was around 195 - 200 when this happened. Car has 5,000 miles on it. Let me know if more info is needed.

Just dropped it at Nissan - anxious for the verdict.

Any ideas??? Man, this sucks:shakes head:

sucks man...hope you get it sorted out.

Wow- let us know what happens. Have you done any mods or anything to the car prior to this happening?

Gl w the dealership.

Does turning the AC off help at all? I noticed Auto air mode puts the AC compressor on by default

hrmm.. maybe a bad battery.

the one on my other car was running about 20 at idle it would waiver and surge sometimes and almost die. new battery = no more issue. Hopefully thats all it is for you also.

Hey guys. thanks for the support.

Mods - HKS intake
AC - was not running, but I have noticed that it turns on occasionally by itself... mostly on startup or when turning on the climate control system.
Battery - usually around 16 at startup... drops down to around 14 when I get moving.

I have a sneaking suspicion it's the thermostat. I've seen the thing climb 20 degrees in 1 second, then drop 30 degrees the next... I know that the 370 runs a little warmer than usual, but that just seems out of the ordinary.

They have in the shop as we speak, so I'll let you guys know as soon as I know more.

Got the code... air/fuel - running lean. I guess I need to start to put my oem intake back in...:mad:

anyone ever get this code before? You'd think I would be running like 8 PSI of boost... Honestly, it doesn't make much sense.

Replies are appreciated.

An intake should not screw up A/F much. I'd lean toward bad MAF sensors in the aftermarket intake. You might try some MAF cleaner on them.

It won't explain your CEL (or at least I can't see how it would), but there have been posts that bad cam angle sensors lead to the rough/bogging idle.

thats a vacuum leak.

James had it also. On the passenger side intake, check that breather hose that goes to your valve covers. I believe that was the culprit on James ride. I fixed that for him, unplugged the battery and it went away and it also fixed his idle.

Ah, okay makes sense. Question is how did you find the leak? Could you hear the leak, or did you actually have to get in there and tighten all those freaking pinch clamps? I remember that being annoying as hell. In any event, thanks for the info... gonna tackle this tomorrow morning.

didnt hear it, his was really minor. Just felt around tugged n checked everything in there.

hell you could just pull the battery for 15 seconds and set it back on and see what happens also. Computers and phones arent the only things that sometimes just need a quick reset.

Disconnected the battery about 20 min ago... that was kinda my plan. Unplug - ask questions later. I'm just gonna make sure everything is good and tight tomorrow.

Well, I tightened all the band clamps on the intake, adjusted all the pinch clamps on the the breather hoses, and NO MORE ROUGH IDLE!!!!

MIL has not come back on, so it appears the problem has been solved! Thank you all for your help!

no prob man. glad it was simple. : ) luckily i had to do that for James car and it worked there too.