Thread: VVL Idle Unsteady. Cause?

My sr20ve, which normally idles at 850rpm, is now idling very unsteadily - fluctuating between 700 and 1200rpm? A sort of humming sound...

When I am coming to a stop the rpm drops way below 500rpm but does shut off.

What could be the cause?

So far my mechanic and I checked:
plugs
plug wires
vacuum hoses
AFM
and cleaned aac valve.

While checking for vacuum leaks, I noticed that when I took off the vacuum hose leading from TB to FPR, it was idling steady but at higher rpm.

Thanks

possibly your tps is not set correctly, there is really only two things that can cause it, a bad idle air control valve or dirty throttle body, or your tps is not set correctly, Mine does the same thing when cold, once warmed up it goes away. But i havent set my tps voltage yet either since i just got the swap in and my buddy has my multimeter. so yeah ive had this same thing happen before when my tps wasnt set to the right voltage. once i set it it stopped and had a nice smooth idle.

Ok.

However, I've had this motor in for over 5 months and it never happened before.

Also felt a little bucking while driving on the highway this morning.

I say bad MAF.

My MAF went bad and I had the same issue.

Suspected that Dre and even called a friend to find out if I could borrow his AFM.

The mechanic was saying that if the AFM was faulty there would be puffs of black smoke and car would not be driveable.

Peace

Are you using the N60 maf?

CHECK water level in radiator

Hooked it up to a diagnostic device - turns out the knock sensor is bad.

Does anyone knows how to 'bridge' it out properly? I have since gotten another one but the bad one is one hell to get off. (limited space at back of motor to operate).

Peace

its knocking for a reason see why.

The motor is not knocking. The knock sensor went bad so the car was retarding.

Peace