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Hey there need some urgent help with my 25/30. I have just installed some tomei 264 poncams and now my car idles like crap. The whole car shakes and vibrates and just doesn't feel right. I have new lifters, upgraded valve springs and retainers, new valve stem seals and the tomei 264 poncams. I have a tomei exhaust cam gear installed with no advance or retard.Controlling everything is a pfc l jetro and I have 700cc injectors.

The car revs and drives ok but idle is horrible. Timing is spot on and no matter how far advance or retard ignition timing or add and take away fuel the idle does not get any better. Now don't get me wrong it changes the idle and ratios but the best idle I can get is still crappy. Every video i see or person i ask that has installed these cams say they are straight drop in and do not affect idle like what I am describing, but my idle woes only happened after the cam install.

I thought bent valves but got a reading of 150 psi on all cylinders doing a dry compression test. Can anyone give any advice? I am totally stumped and bout ready to go back to the original cams cause this idle just is not right.

Anyone with any experience please give some advice.

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What revs are you idling at?

The 260 cams are drop in. I thought the 264 weren't drop in but I could be wrong.

Are you 100 percent sure that they are drop in?

Making it richer at idle typically helps.

Also are you sure they are dialed correctly. I would have thought that the extra duration would drop the cranking psi generated, as it certainly drops manifold vaccum at idle.

I recommend double checking cam timing and drop in status of the cams.

Edited by Ben C34

Purchased from tomei stated they were drop in 264 with 8.5 mm lift, they retain vct, idling at about 1000 rpm,don't know what previous cylinder psi was but got 150 psi dry tested with cams installed. Didn't try any dialing in only have an exhaust cam gear cause intake retains vct, manifold vacuum haas dropped at idle from showing -17 on the boost gauge to showing -8 and idle is horrible. Entire car shakes and sputters.

My 2530 with a neo head and 260 cams idled like stock with slightly higher vacuum.

I know if VCT was activated at idle it idled like crap. Could that be the case with yours?

Edited by Ben C34

My 2530 with a neo head and 260 cams idled like stock with slightly higher vacuum.

I know if VCT was activated at idle it idled like crap. Could that be the case with yours?

No VCT activates correctly.

Dial gauge and timing wheel time.

What do you mean?

How do you know vct activates correctly?

How did you remove the vct pulley? I have heard of them being damaged with a rattle gun when not holding the cam. The correct way us to hold the cam with a spanner then remove the gear.

GTSBOY means it time to check how the cams are setup. Which to be accurate is done using a dial indicator and degree wheel.

How do you know vct activates correctly?

How did you remove the vct pulley? I have heard of them being damaged with a rattle gun when not holding the cam. The correct way us to hold the cam with a spanner then remove the gear.

GTSBOY means it time to check how the cams are setup. Which to be accurate is done using a dial indicator and degree wheel.

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?

The tomei can specs can be download.

Stock balancer is useless for degreeing in the cams. However the issue is likely the cams being out by a whole tooth so aligning the marks is sufficient. Having said that in my experience the marks dont line up well with a 2530 and are out by almost half a tooth . I checked my cams with a degree wheel and found that. So perhaps you are out the other way than before

If the vct pulley has been damaged and stuck on the car would idle shit.

What happens if you activate the vct at idle? Does the idle change at all, if not then the vct is stuck on.

Edited by Ben C34

The tomei can specs can be download.

Stock balancer is useless for degreeing in the cams. However the issue is likely the cams being out by a whole tooth so aligning the marks is sufficient. Having said that in my experience the marks dont line up well with a 2530 and are out by almost half a tooth . I checked my cams with a degree wheel and found that. So perhaps you are out the other way than before

If the vct pulley has been damaged and stuck on the car would idle shit.

What happens if you activate the vct at idle? Does the idle change at all, if not then the vct is stuck on.

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?

I wouldn't touch the cam timing until you can rule out the vct being an issue.

I would activate it manually. Disconnect e plug to protect the PFC and put 12v and earth to it with car running and see what happens. Polarity doesn't matter .

I wouldn't touch the cam timing until you can rule out the vct being an issue.

I would activate it manually. Disconnect e plug to protect the PFC and put 12v and earth to it with car running and see what happens. Polarity doesn't matter .

Will do in the am and let you know results. Thanks for advice.

Advancing the exhaust can would reduce overlap and improve idle if you want to try that.

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.

whatever cam adjustment is loose is the one that is being adjusted, as if the exhuast adjustment is loose and you turn the engine clock wise, the exhaust cam will stay stationary, and the intake cam and crack will spin, and the exhuast cam gear will move slightly, and this will RETARD the the ehxaust cam by making exhuast events happen later in the cycle, it will also increase overlap and cause a shitter idle

I wouldn't touch the cam timing until you can rule out the vct being an issue.

I would activate it manually. Disconnect e plug to protect the PFC and put 12v and earth to it with car running and see what happens. Polarity doesn't matter .

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.

Edited by Daboss

Check you cams are correctly timed before going further in case your a tooth off somewhere.

Check your valve clearances while your there.

It could just be something very basic that was missed on assembly causing it.

All you need to cause this if for a cam to be out a tooth or for a valve shim to have popped out of place.

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