Rough idle - Z31 Performance

codename

Junior Member

Posts: 2
#1

Rough idle

08-23-2019, 12:05 PM

I have a 88 na z31. Easy start up, fires up will run good and idle fine for about 10 minutes. After the idle drops to 700 it misfires. Then misfire will come and go when it wants. All oem new plugs, wires, cap, fuel filter injectors and clean gas. No vaccum leaks. Can not figure this out. Any help?
AzureblueZ

Senior Member

Posts: 121
#2

08-23-2019, 01:36 PM

When I was having a similar issue it turned out that my O2 sensor had gone bad.

85 NA2T 9:1 Compression, CM 3" exhaust, Complete Interior Restoration
94 Maxima
…VG30 FTW!!
FrozenZ

Senior Member

Posts: 584
#3

08-25-2019, 11:27 AM

+1 on O2 sensor, also check and make sure that the O2 sensor harness hasn't flopped on a hot exhaust and partially melted
bacon

Member

Posts: 37
#4

08-27-2019, 10:52 AM

Just curious on this; I have the same issue, but don't get a O2 sensor code. Did you get a code for your bad O2 sensor?
FrozenZ

Senior Member

Posts: 584
#5

08-27-2019, 02:05 PM

Pretty sure the ECU is only checking if you've got conductivity for your O2, not if it's actually working correctly.
AzureblueZ

Senior Member

Posts: 121
#6

08-28-2019, 05:03 PM

Originally posted by bacon View Post

Just curious on this; I have the same issue, but don't get a O2 sensor code. Did you get a code for your bad O2 sensor?

I did not get an O2 sensor code.

85 NA2T 9:1 Compression, CM 3" exhaust, Complete Interior Restoration
94 Maxima
…VG30 FTW!!
badq45t

Senior Member

Posts: 300
#7

09-13-2019, 04:55 AM

Do not count on codes for these cars, not worthless but close. The O2 sensor and/or cylinder head temp sensor could fix it, I am on my 3x for both on my 84'