Hi everyone, I'm having some minor issues with my Z and I'm not sure if they are just normal or what could be causing them. I got the car 2nd hand and it came with an aftermarket exhaust. The first issue is if I'm driving say around 3k rpm and I sink the clutch, the rpms drop to 1000 then bounce back up to 1500 for a few seconds and then drop down to around 1000 again. Not sure if this is normal but I notice it in traffic alot. Secondly when cruising at low rpms if I come off the gas without being extremely careful the car jerks a little it almost feels the fuel has been cut completely. I also had an idle issue with the car when I first got it, it was idling around 1400. I did the idle relearn and it now idles around 1000. So far I have tried the relearns and cleaning the MAF but it hasn't made a difference.

Any help would be greatly appreciated.

Thanks

 

1000 is still quite high..450-750 is norm

 

The 1000 idle is too high .
If you have done the relearn process/cleaned the MAF(be very careful here,easy to damage),still the same...I'd throw some Seafoam in your gas and see what happens.
I'm not big on additives.But this stuff somehow really cures alot of ailments on your car.
My 03 had a rough idle awhile back.Put in some Seafoam,cleared right up.Its so smooth,
can't tell the car is running if it was not for the exhaust.
Try some.

 

That's a great idea... for a 1967 jag xke ..

Op.. do you have anything after market in your intake path? I'd check for vacuum.leaks, do the Carb cleaner spray trick around all parts you've installed non oem in the intake path.. the jumping up of your rpms is odd.
I'm thinking vacuum leaks, throttle body issue or something similar.. nit anything sea foams going to fix.. there's more to do here before adding naphtha oil in your gas.

Do you have any cel lights when it occurs?

 

10,000 or 200,000 miles on the car? You think this may be an important fact?

 

Thanks for the replies, the car has 90000 miles and nothing aftermarket on the intake side. I followed instructions online to clean the maf just spraying it with the crc spray as it said. Everything I have read online has had me leaning to a TB issue as well. I don't have a cel at all and yes I thought 1000 was a bit high, I had another Z before but I couldn't remember if it idled like that or not. I'll make a video of the rev jumping, in one of my previous cars I had a air fuel ratio gauge and it reminds me of when I came off the gas in that times and the ratio went lean.

Thanks for all the help.

 

Ok so I finally got the video up, it doesn't show it the best as it is more obvious in traffic but I was cruising in 6th I believe and when you see the rpms drop I sunk the clutch and kept in sunk until the end of the video. Let me know if you guys have any idea what this could be. Thanks! http://youtu.be/XH6Q1W60YII

 

Hi all, I have a question....Last year, while driving I lost power dramatically, lights came on and the 350z 2003, would barely restart. Replaced Cam sensors, now my car has almost 100,000 miles, ran again no issues, and it is running pretty rough now, seems to be really bad when the car is cold, mind you I live in a tropical climate:] it is a standard, and it doesn't make any sense. so, my question is, I had after market sensors put in, took it to Nissan, even though it ran rough they could not find the issue, the 100.00 car wash I call it, my car must have been awesome before this idle issue! Oil is changed regularly, gas is maintained at what it requires, never any additives. I am wondering if stock cam sensors would fix this, what about clutch, timing chain? We already did the spark plugs. The idle doesn't create an rpm issue, it just feels rough and the shifter shakes a little. Any ideas? Anyone have this issue with a good fix? Thanks,
Kate