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Tps voltage 0.5 with ignition on still 0.5 at idle. With ignition on and accelerator floored tps voltage 4.34. Tried the crab cleaner there was no change in idle, couldn't get underneath the intake but sprayed everywhere else.

I am fresh out of ideas last thing left is for me to have a go at the exhaust cam gear. I also shot a video that I will be trying to upload for you guys to see and make your own analysis.

Edited by Daboss
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I was under the impression that no-one had successfully undertaken the internal vct supply mod. I guess to be absolutely sure that it is working as it is supposed to you would have to check on a dyno. Maybe you could try a timed 80 -120 run with the vct on and off and see if there is any difference.

Advanced exhaust cam gear 6 degrees engine is a lot smoother; still can feel vibration when sitting in the car and at idle vacuum is in the 10's.

Did a wide open pull in second full boost came on at around 4700rpm out of a holset hx40 with a twin scroll t4 .58 back housing. Pulled very stringly at the onset of boost enough to spin the tires at 12psi, Still needs a tune. Does that seem laggy?

Car still does not feel right, can not control idle from pfc stays around 1000rpm and when i lower it using the hand controller the rpm rises.

do a boost leak test see if you can find a leak... open the throttle as well with a brick on the pedal and spray soapy water on everything ...then find bubbles. do you have idle air control valve? or is it all ditched?

do a boost leak test see if you can find a leak... open the throttle as well with a brick on the pedal and spray soapy water on everything ...then find bubbles. do you have idle air control valve? or is it all ditched?

I have idle air control valve.

The brick on pedal is while doing the boost leak test?

Cams would reduce vacuum as well right? By reduce i mean going from -17 to -10.

I was under the impression that no-one had successfully undertaken the internal vct supply mod. I guess to be absolutely sure that it is working as it is supposed to you would have to check on a dyno. Maybe you could try a timed 80 -120 run with the vct on and off and see if there is any difference.

I have the internal mod successfully running vct on hks cams

if your vacuum has decreased then perhap more air is needed to bypass the throttle through the idle air control...have you played with that at all?

Yeah had a play with it. Didn't check to see if it increased vacuum but will when I go at it again. That's probably why it isn't working how it suppose to be. Use to be able to control idle perfectly with power fc. Guess I will mess with it again until I am able to control with the power fc again.

I have the internal mod successfully running vct on hks cams

Really? Ok how is your restrictor setup in the block? How does your car drive with it unplugged? Is there a noticeable difference with it on or off?

Mines doesnt work cause I did the idle test by activating it while car idling and there was no idle change and also I have it unplugged now and driveabilty is the same. No change at all.

Edited by Daboss

someone here will have the answer, but these are my thoughts and i'm still really learning so i could be wrong but advancing the exhaust cam timing will decrease overlap and increase cylinder pressure...which would lead to more heat being generated.

Edited by Badgaz

Yeah had a play with it. Didn't check to see if it increased vacuum but will when I go at it again. That's probably why it isn't working how it suppose to be. Use to be able to control idle perfectly with power fc. Guess I will mess with it again until I am able to control with the power fc again.

Really? Ok how is your restrictor setup in the block? How does your car drive with it unplugged? Is there a noticeable difference with it on or off?

Mines doesnt work cause I did the idle test by activating it while car idling and there was no idle change and also I have it unplugged now and driveabilty is the same. No change at all.

Vct is 1.5mm Middle blocked and rear 1.4mm. Idle is poor with the vct turned on and with it off the midrange is about 40kw less

Vct is 1.5mm Middle blocked and rear 1.4mm. Idle is poor with the vct turned on and with it off the midrange is about 40kw less.

Same specs with my build. Only thing is i havent been on a dyno to check power output as yet. Most definitely there is no idle change when vct activated at idle and it feels the same driving wise whether plug is on or off.

Other than the idle check i have noway of telling if it is actually always on, cause driveablity remains the same but that could be the effect of it always being on and idle is poor after cam install. Vacuum at idle is in the -10's rising the more rpm I make without getting into boost.

Checked and rechecked timing, added and subtracted both fuel and ignition timing, opened and closed idle air control valve, adjusted tps sensor and advanced exhaust cam gear 6 degrees.

Everything is within spec just idle is not as smooth as i would like it to be car vibrates and engine shakes to much. It is not horrid just a little off and its bugging the hell out of me.

The cam gear advance seemed to help a bit but didn't want to go any further than that as it seemed to far advance at 6.

So I am back to it either being vct or cams, also i have a very small gap on my spark plugs,

its odd that you cant adjust the revs lower than 1000rpms, what gap are the plugs? are they getting wet cause once there wet it will never idle smooth.

Plugs are gapped very tightly. I am thinking they are .5mm. Have not checked the plugs for wetness. I reinitialized the power fc and did the idle learn again, Rpm is steady at 950/1000 according to hand controller and I have it set at 900. That is with the idle air screw opened all the way. Didnt try to adjust with hand controller as it was kinda idling within spec.

Feel that controlling the idle is within my grasp as it is now idling steadily between 950 and 1000 and i have a few adjustments I can make to get it as close to perfect as I can.

What injectors?

650cc about to be changed to 850cc top feed denso.

Problem seems to be solved. CAS was broken. Car now idles as before with a slight miss but no violent shaking. I have noticed that my water temperature gets noticeably higher than what I am use to. Use to seeing about 95c to 98c staying there under normal conditions and boosting with fans running as soon as hood opened with fans on temps would drop down to low 80'sand thermo fans would cutoff. Temps would build back up fans cut back on and so on and so on.

Now the temp gets to 102c and stays there even with hood open, fans on and after a hard run.

Can advancing the exhaust cam gear raise water temps? I ask because while trying to fix idle problem I had advance the exhaust cam 6 degrees and have not placed it back to normal.

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