Daboss

Thought it was solved guess I talked to early. During a cold start the car barley wants to keep on. whole car vibrates and shutters like before. Afr/s are in the 10's and vacuum still showing single digits. I have to literally keep foot on gas pedal to get rpm's up to stop shaking slightly. After holding rpm for a minute give or take a few seconds and pedal released, idle raises and car somewhat behaves until warmed up a little. Once warm it still has a little stutter but not as bad as at idle/cold start. Car revs cleanly and during normal driving conditions vacuum is the mid to high teens, during decel vacuum is in the 20's on boost guage but when settled at idle vacuum is back to single digits. Exhaust cam gear is advanced 6 degrees. Don t know if that is the cause of anything but would just like to give all the information about setup as I can. Also plugs are gapped extremely tight, i believe them to be about .,5mm gap. Tuned the car a little and now running about 17 to 20psi. Boost feels to come on a bit later, but when it does car pulls like a jet plane. Its just the idle leaves much to be desired at cold start when warmed sometimes it seems to drop a cylinder and idle raises and holds to above 1100 but that's only after boosting and I blame that on the mixture of methanol and fuel as i have meth injection. My water temps have also increased to like 102 degrees Celsius just idle and normal driving from about 95/98c driving under boost on hot days and no matter what i do they do not drop. I have a dual core aluminum radiator with a shroud and two ten inch fans running off a thermostat and a nismo cooler theromstat. The system is filled with a full coolant mix and a 50/50 premix. Do you think the exhaust cam advance or installation of the new cams has anything to do with the increase in temp? Also why is idle vacuum so low? While driving under vacuum it seems normal and also on decel, but at idle its in the single digits. Not saying its wrong just would like to know if it is normal.

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. 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.

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,

Sorry bout that the exhaust cam?

Quick question does advancing the cam timing or retarding the crank angle sensor produce more heat coming from the engine?

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.

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.

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.

If that's the case then I doubt it working then, cause I have it unplugged now and drivability has not changed in the slightest.

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.

Yeah ahhh no such luck with the tuner as we don't have local tuners down here have to fly them in periodically as a group and who knows when the next time is. I thought the overlap of the bigger cams would cause less vacuum. Going to check tops voltage and do card cleaner test and let you guys know the results.

So the 264 cams wont reduce vacuum?. It will take off at idle just using clutch but it is very jerky. Will test thoroughly today to make sure. Carby cleaner test is just to spray around plenum and listen for idle change?

Maybe but it doesn't hunt around and I put it to that afr I can lean it out more its just the best feeling afr for idle to me. But its no problem leaning it out idle gets really bad in the mid 14's. Me either that's why I am going crazy. Thought it would be a simple drop cam in job. Like I said it revs ok and driving around off boost is good as well its just when idling or coming to idle it sucks. With vct disconnected on a 25/30 can anyone confirm that it feels like a pig to drive down low?

At first the car didn't want to start had to give it gas and hold the accelerator down in order to keep it running. That's why timing and bent valves were assumed, but did test to make sure both were in good order. After a bit of tuning on the hand controller according to the wide band sensor afr's are around 13 at idle.

The internal one. Where you remove the brass plug from underneath the intake cam groove at front of the head and drill holes in that same brass plug to allow oil to get to the vct part of the cam. http://www.sau.com.au/forums/topic/251669-rb2530-rb30det-vvt-internal-oil-control/ Will check tps voltage at idle, rpm is set to 900, injector latency is .34 and size are 700cc, Tried moving the latency around and injector size to tune it out with no luck. The car ran fine before cam install. Never tested the vct before so that may not have been working from engine was put together, Just assumed it was because the solenoid activated, but the displacement of the 30 bottom end may have made up for the lack of vct and just happen to realize the vct mod didn't work now because of the current problem.

Ok cause you had me worried there for a minute. So does anyone have any other suggestions? Even if I were to degree the cams tomei sight does not have any numbers for 264 poncams and I will only be able to adjust the exhaust side seeing as the intake side retains vct pulley. The timimg has been done over and over again and it is on time. The symptoms of the car does point to vct always being enabled as I can drive around with the solenoid plug off and car is not sluggish at all. Do you think that somehow by doing the internal vct mod it is now constantly activated? Are there any other test I can try to confirm vct is always engaged?

No change at all and yes rechecked timing. No I didn't bleed lifters didn't know I had to seeing as they were new and hydraulic just installed them. They seem to be primed correctly as there is no lifter tick. How would i prime them for future reference?

No it drives nicely off boost its just when settling to idle that it jerks and shakes. Also coming on to boost feels a bit laggier but it pulls hard when boost comes on. Well I only tried it in second and i got a strong pull, Yes all six cylinders running and coil packs plugged in. Did the vct gear replacement got the same results idle is a bit rough and engine shakes. Also with different gear installed tried to activate the vct manually it clicked but no change in idle. Tried to activate vct manually on a friends rb25/30 as well at idle and idle didnt change. He has stock cams and we both did the internal vct mod to keep vct with the 25/30 combination. I drove around today with vct solenoid unplugged and car drove nicely except for the shutter and jerking when coming to idle or taking off from idle.

Drives ok as in does not miss or stutter when revved and also on boost it pulls but can use some fine tuning to get it right. Feels a bit sluggish to get on boost but when on boost can feel the pull.

What shim? The lifters are hydraulic and I installed brand new set. I think you only shim solid lifters.

Ok folks i did this test and the solenoid activates. I can hear it clicking, but the idle remains the same it does not change same crap idle at same rev. So whats the next step find another vct cam pulley and change it out? What is actually damaged? Can you explain what happened? More than likely the mechanic used an impact gun to get it off without holding the cam down.

Will do in the am and let you know results. Thanks for advice. with the exhaust gear i noticed you spin the crank while having the bolts that secure the gear loosened, this causes gear to move without moving cam itself which by default moves everything except the exhaust cam. I know that advances or retards it depending on which way you turn. What i want to know is on the gear it shows clockwise as advance and counterclockwise as retard, but if i advance it will move the intake forward while keeping the exhaust tdc. Is that advancing the exhaust cause from what i am picturing it seems to be advancing the intake cause it opening the intake valves slightly earlier than than the exhaust set. Or am I just mixed up and over thinking it a bit to much? I will activate vct firstly thogh and see if idle changes before I fool with exhaust gear. Is there any other way to tell if i am out a tooth? Like I said we checked and rechecked and everything lines up fine.

Yea I just took a look and the only numbers I can find for the poncams with hydraulic lifters and vct are intake 120 and exhaust 115, but that is for the 256 with 8.5mm lift the set I have are 264 with 8.5mm lift. Which I see no info for. As for activating vct at idle I cant it only activates when I rev the car. I can hear the solenoid activate and on the pfc controller the vct indicator lights up hand controller wise the dot darkens. Dont have a degree wheel. We timed and retimed it and it seems to be spot on. All the marks are lined up from timing gear on crank to cam gears and harmonic balancer all lined up with belt on and in place and rotating by hand a few times. Do you think i should have a go at the exhaust cam retarding or advancing that seeing as that is the only gear I have that I can adjust anyway? To see if it helps with this horrid idle. Any suggestions on which way to start?

Cause looking at the pfc sensor check and listening to the car you can hear it click at about 1500 and see the sensor indicator light up on the pfc hand controller. So i would need a timing wheel with the 360 degree marks and the dial indicator to place onto the lifter? The cams didnt come with a sheet to see what it shou;d be dialed in at though as they were just suppose to be drop ins. What would I be looking for exactly and can it be done with stock harmonic balancer?

No VCT activates correctly. What do you mean?