Help, Idle Problems And Turbo Problems - Rb20det

[R32-PSH77]

Hey guys.. i have recently upgraded the turbo on my Rb20det. to a T3/T4 using the RB25 exhuast housing thats been high flowed and a T4 Front housing and wheel ect.

Anyways i have bolted it onto the stock manifold and bought a new 3" mandrel exhuast from turbo back.. including highflow cat. Also bought a new bosch 023 800hp in tank fuel pump which i have all installed.

No my problem has been ever sinse i installed the turbo the car wont idle properly.. i know i need tog et the car tuned.. but money has become a bit of an issue at the moment.. so i drive the car quite conservatively and the boost is only a mere 7psi. but the idle not hunts up and down horrible.. and stall's quiet frequently... It seems to drive perfectly when its still on cold start.. like driven for the fist time of the day.. u put your foot on the clutch and the idle stays perfect.. but as soon as its warmed up.. as soo as you pull up and u put your foot on the clutch the idle drops to 0 and it stalls..

EXtermely imbarrasing.. i dont know what to look for.. i dont think its a simple case of turbing up the idle.. because if i give the throttle a little tap before it stalls.. it regains to around 500-700 rpm anmd hunt s a little.. but manages to idle a bit. so thats problem number one..

Also number two.. The new turbo seems to be surging.. it hasnt done it recently as i have tried boosting it at all.. but under heavy load.. eg going up a hill in a higher gear.. the compressor seems to fluctuates rapidly.. making a whoop whoop whoop sound.. it doesnt like being under laod at all.. its like the wastegate spring is too soft or something..

Anyways i got to goto work now.. if u need anymore information.. please let me know what u need to know.. and i'll anwser as best i can.. Thanks,.

[R31Nismoid]

What BOV setup are you using?

[FOG35]

I also have a RB20 with a R33 series 2 highflow and am having the same surging problem between 3000 and 4000rpm under load (at all other rpm turbo is perfect!)

I will be watching this thread!

[blind_elk]

I reckon:

The problem at boost is compressor surge - you need a re-program of the ECU.

The idle problem is either an air leak (hose off somewhere) or a dirty AAC valve.

[R32-PSH77]

at the moment im using a Amto BOV.. but i never had this idel problem before i setup the new turbo.. i used to have the return pip[e from the standard setup blocked of and im currently running a Type 3 turbosmart bov.. ive tried it wound up tight and mid range.. both have no effect on idle.. its really ghey.. i sorta have to bleep the throttle before coming to a complete stop.. to stop it from stalling.. and feather the throttle in conjunction with the handbreak to pull up the car without stalling... i don't see how having a diffrent turbo would effect the intake of air during idle.. its barely spooling at idle is that right?? could it be a shagged AFM?

[R31Nismoid]

Put the stock BOV back on and report back.

Many a prior expirience tells me your about to solve your problem

[barney]

Put the stock BOV back on and report back.

Many a prior expirience tells me your about to solve your problem

Yeah, what ash said

that'll fix the stalling at the lights.

[Starionturbo]

My ceffy has no blow off valve and this problem has come about all of a sudden.

Last service about 2 weeks ago, I noticed one of the lines to the charcoal cannister had perished and pretty much come offso I put a new vaccum hose on.

I thought this would solve my problem.

Since then its the same thing, come to the lights the idle hunts, it doesnt stall but it gets DAMMN close.

Ive checked over the vac lines plenty of times. The air flow meter has been cleaned, oxy sensor replaced.

I dont know what else? Im getting horrendous Fuel economy as well - like insanely bad.

[Hydroxinol]

No my problem has been ever sinse i installed the turbo the car wont idle properly.. i know i need tog et the car tuned.. but money has become a bit of an issue at the moment.. so i drive the car quite conservatively and the boost is only a mere 7psi. but the idle not hunts up and down horrible.. and stall's quiet frequently... It seems to drive perfectly when its still on cold start.. like driven for the fist time of the day.. u put your foot on the clutch and the idle stays perfect.. but as soon as its warmed up.. as soo as you pull up and u put your foot on the clutch the idle drops to 0 and it stalls..

Sorry to resurrect an old thread but it looks like this never got resolved.

I have the EXACT same problem. It started ever since I installed an RB25Turbo on my RB20DET with a stock BOV. At first I thought it was due to an air leak, but I fixed it with no success. I have also recently cleaned my AFM and AAC Valve. I was having idle hunting issues before I installed the turbo, and this was solved by cleaning the AAC Valve. Is it possible that it or something else could have become clogged up again while running the new turbo in? I have also tried reseting my ECU with no luck. I notice at idle that the vacuum reading on my boost guage seems to fluctuate slightly, don't know if this is the problem, or a symptom.

Any ideas?

Edited January 15, 2008 by Hydroxinol

[Hydroxinol]

I solved my Idle problem.

Symptoms:

Car idle slowly drops down to near stalling and then raises back up to normal idle momentarily. This only occurs when stationary at idle with car at operating temperature. Tapping the accelerator will also send the idle on a skydive down and it will studder until it slowly raises back to normal.

Cause:

Faulty O2 Sensor. The car idles normal at cold start because the ECU ignores the O2 Sensor until it is at operating temperature. Once the O2 Sensor is at operating temperature, the ECU will begin to read the voltage from it. If your O2 Sensor is faulty, it will not be able to give the ECU a quick, accurate result, and will result in poor idle as the ECU acts on this false reading.

Solution:

Check O2 Sensor with a multimeter to confirm if it is faulty/dead. The following site contains an FAQ on how to do this: O2 Sensor FAQ

On my multimeter I noticed that it did not go under 0.45V, and when revved at 2,000rpm it stayed at a constant voltage. It shouldnt do this, a functional O2 Sensor should fluctuate rapidly.

Hope this helps.