Fluctuating Idle
#1
Registered User
Thread Starter
Fluctuating Idle
Hey guys, my idle is fluctuating between 1500 and 2 k rpm. I read thru a couple of the threads on here and still can't seem to figure it out. At first my mechanic said his scanner was showing the throttle body code so I ordered 2 used and he changed those out, code went and and yet the problem remained. Not sure what else to do, I am thinking maybe somehow my tune went bad? I left the car and went on vacation during the cold season then when I came back i noticed this issue. It actually started a bit of rough idle before the trip but not this bad. Mechanic tried the relearn using his scan tool and also tried to do it manually. Any suggestions? car is a 2007 tuned 350z hr with oversized intakes and big injectors
UPDATE
Just providing you all with an update. I am still having this issue, I have had the car checked out by multiple mechanics. All have no idea what is going on. I actually went to a Nissan dealership and had them do a diagnostic test on the car and they have no idea what is the exact problem. They suggested that I buy brand new throttle bodies from them totally $2200. They are not even sure this will correct the issue. However they did say they saw a misfire code in their scanner from a few cycles ago.
Today I took the car to a popular shop in the Miami area. He tried and failed saying he doesn't believe its a mechanical issue. I am thinking maybe my an injector went bad casing the fluctuating idle and the miss fire found in the history. I am thinking of going to my tuner to see if he can possible use uprev to control the idle. That is my last hope I have no idea what else to do. If this fails I might sell the car and get a daily to drive around before picking up a new toy in a few months. Any suggestions?
UPDATE
Just providing you all with an update. I am still having this issue, I have had the car checked out by multiple mechanics. All have no idea what is going on. I actually went to a Nissan dealership and had them do a diagnostic test on the car and they have no idea what is the exact problem. They suggested that I buy brand new throttle bodies from them totally $2200. They are not even sure this will correct the issue. However they did say they saw a misfire code in their scanner from a few cycles ago.
Today I took the car to a popular shop in the Miami area. He tried and failed saying he doesn't believe its a mechanical issue. I am thinking maybe my an injector went bad casing the fluctuating idle and the miss fire found in the history. I am thinking of going to my tuner to see if he can possible use uprev to control the idle. That is my last hope I have no idea what else to do. If this fails I might sell the car and get a daily to drive around before picking up a new toy in a few months. Any suggestions?
Last edited by The_Assassin; 04-30-2016 at 08:07 PM.
#2
General & Tech Moderator
MY350Z.COM
MY350Z.COM
Grab a vacuum guage, hook it onto intake plenum. I'll buy you a pint if it's not a vacuum leak. Post up when you find the problem!
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The_Assassin (03-23-2016)
#3
Registered User
Thread Starter
Thanks for the response, he actually did check for vacuum leaks but I didn't see him use a special gauge or anything. You think its best to try this and not take it to the tuner? I already wasted money on throttle bodies that I am not even sure was the issue. Hopefully I can resell If I find out they are in working condition.
#4
General & Tech Moderator
MY350Z.COM
MY350Z.COM
It does sound like you have a lot of moving parts. With an inexpensive gauge, this is an easy point to rule in/out. gl
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The_Assassin (03-23-2016)
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The_Assassin (03-23-2016)
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The_Assassin (03-23-2016)
#7
New Member
A smoke test will reveal pretty much any leak. Most halfway decent shops have an automotive smoke machine.
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The_Assassin (03-23-2016)
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#8
Registered User
Thread Starter
#9
Registered User
Thread Starter
Anyone think that there could be a problem with my tune ?
#10
New Member
Without seeing what the shop actually did during your tune, it's anyone's guess. That being said, if the problem surfaced right after they performed it, then odds are it'd be a good place to start.
#12
Registered User
Thread Starter
No the problem started maybe 6 months or so after the tune. He did have a problem with injector scaling though. With the bigger intakes and injectors the car was idling horribly until he got it sorted out.
I had big plans for the car was eventually going to get a Boosted performance kit. I have dual 3.5 inch custom made intakes and some people on here also changed their injectors when they got theirs installed so I figured why not do it.
#13
Registered User
Thread Starter
Just providing you all with an update. I am still having this issue, I have had the car checked out by multiple mechanics. All have no idea what is going on. I actually went to a Nissan dealership and had them do a diagnostic test on the car and they have no idea what is the exact problem. They suggested that I buy brand new throttle bodies from them totally $2200. They are not even sure this will correct the issue. However they did say they saw a misfire code in their scanner from a few cycles ago.
Today I took the car to a popular shop in the Miami area. He tried and failed saying he doesn't believe its a mechanical issue. I am thinking maybe my an injector went bad casing the fluctuating idle and the miss fire found in the history. I am thinking of going to my tuner to see if he can possible use uprev to control the idle. That is my last hope I have no idea what else to do. If this fails I might sell the car and get a daily to drive around before picking up a new toy in a few months. Any suggestions?
Today I took the car to a popular shop in the Miami area. He tried and failed saying he doesn't believe its a mechanical issue. I am thinking maybe my an injector went bad casing the fluctuating idle and the miss fire found in the history. I am thinking of going to my tuner to see if he can possible use uprev to control the idle. That is my last hope I have no idea what else to do. If this fails I might sell the car and get a daily to drive around before picking up a new toy in a few months. Any suggestions?
#15
Registered User
Thread Starter
#18
Registered User
Thread Starter
Thanks for the heads up on the throttle bodies. Yea I have an appointment with my tuner for next Saturday.
Last edited by The_Assassin; 05-07-2016 at 09:42 AM.
#19
Registered User
Thread Starter
Just to provide some sort of closure to this issue. I was never able to fix my Z. I got rid of it a few months ago and picked up a c7 corvette 3LT Z51 performance. Will be posting that up in the other cars section soon.