[Datsun770]

Yeah? Even though it rubs absolutely fine otherwise? I was thinking a leaky vacuum hose or something similar. Jeez hope it's not those just yet yikes. Did this resolve it for yourself?

[Datsun770]

When the idle drops and engine shakes it stays at the same RPM. the REVS aren't Lumpy or inconsistent its purely when the revs his that base level things get shaky. I'd have thought injectors would have caused a jumpy rough idle. But thanks for the info. 🙏🙏🙏

[iqraceworks]

Originally Posted by Datsun770

Yeah? Even though it rubs absolutely fine otherwise? I was thinking a leaky vacuum hose or something similar. Jeez hope it's not those just yet yikes. Did this resolve it for yourself?

Yes. When the motor has been off for a while the injector(s) leaks out fuel , which runa down right onto the tip of the spark plugs loading it up with all kinds of fuel. When you start the motor, it will rev up a little and then settle into an idle. If you have a plug or two that's got fuel on the tip...it's not going to fire very well and make the motor run rough. After it runs for a bit and burns all the excess fuel off of the plugs..it's good to go.

After you car sits all night, pull all of the spark plugs out in the morning and see if any are wet or smell like fuel. If so, those cylinders have a leaky injector.

[Datsun770]

Interesting. I'll do that. Funny that at 100rpm more than the standard idle all shakyness goes away. Doesn't shake at all otherwise. Thanks

[Saif2018]

Originally Posted by Datsun770

Interesting. I'll do that. Funny that at 100rpm more than the standard idle all shakyness goes away. Doesn't shake at all otherwise. Thanks

Hope your injectors aren't leaking but I also upped the idle speed to around 750rpm and found the car idled smoother. I have Index 12's fitted few months ago, no leaking injectors.

[Datsun770]

Thanks. I'm not intending in keeping the car long term so won't be spending 2k on Injectors. A used set may be an option though. I'll have this investigated. Appreciate your help.

[AWD Addict]

I have the same idle improvement with another 100 rpms.

Injectors seem fine.

[Mustafa.e92]

My idles set at 1k smfw life

[randythedrummer]

550 rpm. Smooth as silk.

[AWD Addict]

That makes me sad. I run 750 for it to be shudder free.

I'm sure it's an injector. None of them are leaking noticeably though.