when I change my timing belt on the rb25det, where is the timing mark when reset

[exodus5547097]

when I change my timing belt on the rb25det, where is the timing mark at when reset?

[nizmo zilvia]

There are two (2) circle dots on the cam gears themselves. You should see them. Also you have the back plate for the cam gear and mine had a small yellow line on them where they should match up on each side. I dunno if its the same for the RB25 with the back plate but thats how mine was when I changed it. They should line up perfectly and keep spinning the crank until they line up.

Also the FSM has info on how to do it. Check that out too. Cheers!

[Shocker]

heh, this is a huge job, not extremely hard, but make sure your DEAD on before you consider turning the motor over. Like Nismo said, make sure the cam gears are lined up with the dots at TDC along with the crank gear. Then use the marks on the belt and allign it all. Make sure the tensioner is loose and the idler is tightened when you do this as well.

I start with the bottom gear first on the crank then get her around the exhaust side cam lobe making sure the belt is as far forward as possible w/o falling off, then use all my mite to slide the intake side on... Might take a few tries.

[nyc240sx]

i have a question on this too when you put your crank pulley back in do you line up the yellow mark on the crank pully to the mark on the cover?thanks

[Coolwhip]

depending on what may be indicated yellow on your balancer... your crank snout key way will be pointing 12 o'clock at TDC.

[nyc240sx]

ok so i have it set at 0 btdc on the crank pully dont it have to be at 15? Ive had it like that for a long time the car runs fine but i was thinking if the crank pulley is set at 15 ill see boost quicker is that true?What is the factory position?
Modified by nyc240sx at 7:29 AM 10/23/2009

[nyc240sx]

no one knows huh?

[rb25det250sx]

15* btdc is what the timing should be at.

[robbie2883]

15* btdc is what the timing should be at.

just to clarify 15* btdc is what the IGNITION timing should be set at. NOT the CAM timing

cam timing should be set at perfect top dead center

[nyc240sx]

ok cool because i have the crank pulley set at 0 currently

[nyc240sx]

the fsm also says 0 degree when you change your timing belt i dont understand why it has to be set at 15

[Darius]

Ignition timing is not the same as mechanical timing! 15*BTDC is the ignition timing setting after you get the motor running.

Set the cam gears so the dots line up with the marks on the rear timing cover. Next, set the crank timing gear dot at the approximate notch in the oil pump "lip". Then, make sure the timing belt marks line up with the dots on the cam gears and the dot on the crank timing gear. The crank pulley should not be on when you do this in case you were thinking that. There is a lot of talk about the crank pulley so it is making me leary that you're not setting the belt correctly.

[nyc240sx]

I have my timing belt set correctly all the dots i have were lined up with the dots on the cover and the oil pump...I know theres multiple lines on the crank pulley thats what i was talking about mine is set on the yellow/orange mark which is 0* its the first mark from the right... Is that where its supposed to be?

[rb25det250sx]

wow...man. set your timing belt. tension it. put everything bac together. start your car. losen the CAS up so you can move it bac and forth. hook up a timing light. let your car warm up to proper operating temp. the crank pully has 6 marks on it. 1st one is orange the rest are white. it goes in order from left to right. each line is 5 degrees. 1st line is 0* set ignition timing at 15* by turning the CAS while your shooting the timing light at the crank pully to find out where timing is at. once reached 15* tighten CAS. and put away timing light. then turn off the car shut off the lights and go read the FSM.

[nyc240sx]

My car has been done for the past 8 months and its been running nice iam just concerned with the crank pulley part since iam going to loosen up my timing belt i wanna know which mark on the pulley to set it at?i have my cas set correctly on the stock mark just how i got my motor my car runs fine i dont have any problems with it. But you guys still no answering my question I have my crank pulley set on the orange mark the manual says it has to be set on 0* the orange mark...why do you guys say it has to be on 15*btdc The reason iam asking this i have to take my crank pulley off again to loosen up my timing belt its too tight and i wanna make sure i put the crank pulley on the right mark its on 0* currently you guys say it has to be on 15* on the pulley 3 mark from the right???THANK YOU

Modified by nyc240sx at 4:35 AM 10/27/2009
Modified by nyc240sx at 4:42 AM 10/27/2009

[Darius]

I have my timing belt set correctly all the dots i have were lined up with the dots on the cover and the oil pump...I know theres multiple lines on the crank pulley thats what i was talking about mine is set on the yellow/orange mark which is 0* its the first mark from the right... Is that where its supposed to be?

Dude, it isn't us that isn't answering your question, it is your misinterpretation of the FSM and our responses.

First, before anything else, you say you lined all the gears up with the marks and installed the belt. I say screw the marks because they aren't exact. Especially the oil pump notch. You could easily install it one tooth off. You have to go by the marks on the timing belt matching the dots on the cam gears and crank timing gear. If you did that and are 100% sure of it, then continue to the next comment. If not, or you are questioning yourself, verify it before putting it back together. Count the teeth in the belt between the exhaust cam gear dot and the dot on the crank timing gear. Should be 47. See page EN-56.

Okay, the FSM is not telling you that you need your crank pulley to be at 15*BTDC upon installation. What you are reading into is the ignition timing setting for base timing when the engine has warmed up. rb25det250sx is right. Once you have verified the timing belt is installed at the correct position, button everything up and reinstall the CAS in the center of the slots. Get a timing light and check the timing. If after the engine warms up, it is not at 15*BTDC, slightly rotate the CAS until the third white bar lines up with the bump on the lower timing cover. Tighten the CAS down and off you go.

Get back to this if you have any further questions.

[nyc240sx]

ok cool i have my timing belt lined up perfectly with all the dots on the cam gears and crank gear my car is currently in driving mode ill check the timing one of these days but it might be on 0* thats how i lined up the crank pulley yellow mark with the lower timing cover mark..
Modified by nyc240sx at 5:50 AM 10/27/2009

[Darius]

Cool!

Does that mean you hooked a timing light to it and set the CAS to where the orange mark lines up with the bump on the lower timing cover? If so, that is safe. Once you advance it to the third mark (=15*BTDC), you will notice a sizeable jump in power

[nyc240sx]

yes thats correct i wanna reach more power how would i adjust it to the 15btdc mark do i have to remove the pulley off on the 0* mark and then set it on the 15* mark?Also when i first did the timing on the car my motor was hanging on the lift everything was lined up so i never used a timing light on it but i wanna advance it to 15*btdc for more power
Modified by nyc240sx at 6:04 AM 10/27/2009

[Darius]

Here is where you are still confused LOL. The ignition timing is different from the mechanical timing of the engine. The cams and crank always have the same mechanical timing because the belt insures that it does not change (ignore intake cam VCT). If not, the valves and pistons would meet and valves go bye-bye along with the pistons and head that their pieces chew up.

The ignition timing is when the spark plug is called to fire. ENTIRELY different from mechanical timing. Ignition is determined by the clocking of the CAS with respect to the exhaust cam, which is directly driven by the crank. SO it is impossible to remove the crank pulley and reinstall it at any different position than ZERO TDC. The ignition timing is adjusted by rotating the CAS. Hence, why there are slots in the CAS housing and not just holes.

In order to set the ignition timing, you need a timing light. Once you get it hooked up and pointed at the crank pulley, you'll see what I mean.

[rb25det250sx]

i think i just realized what you were trying to say.. lol. th crank pully only goes on one way, becasue of the half moon shaped peice which holds it on. then bolt it bac in place. setting the timing belt is somewhat difficult, thats why i went to darius for my first time. lol(not to b be ment in any sick way) but i totally understand. the crank pully can only go on one way. once you get that on the rest is a cake walk. just set ignition timing, and your off to the races.

but darius, i never fully understood, do you or do you not have to unpluf the tps when setting the ignition timing. i never did. but my car is set to idle at 800rpm, and when cold started it lobes bad like it has huge cams and often dies till i rev it up enough to somewhat warm it up.

[s14_sport]

I know this guy nyc240sx....leon if you're still confused give me a call. I was confused at first about timing this motor so I sorta understand where he's coming from...

[Darius]

...but darius, i never fully understood, do you or do you not have to unpluf the tps when setting the ignition timing. i never did. but my car is set to idle at 800rpm, and when cold started it lobes bad like it has huge cams and often dies till i rev it up enough to somewhat warm it up.

Not necessarily. Sometimes unplugging the TPS causes the idle to surge. Try it both ways and see which works best. I timed mine with the TPS still plugged in and it works perfectly fine.

If your idle is surging, you could also have a vacuum leak somewhere.

Good man s14_sport! Help a brother out!

[s14_sport]

Hey Matt! I was trying to search for an old post I vaguely remember somewhere about someone telling someone that they had beautiful little valve cover screws for sale. I have a feeling it was you?

is it true? do you have them?

[Darius]

Yep that's me! l0nestar has been my advertising agent on those since he received his this spring.

I don't have any ready for shipment right now, but depending on what you want, I might be able to put a set together for you this week. e-mail me and let me know what you are looking for

[rb25det250sx]

Not necessarily. Sometimes unplugging the TPS causes the idle to surge. Try it both ways and see which works best. I timed mine with the TPS still plugged in and it works perfectly fine.

If your idle is surging, you could also have a vacuum leak somewhere.

Good man s14_sport! Help a brother out!

huh.. nopt sure then. checked for boost leaks at the bigging of the summer. checked out to 25psi, after i fixed them.