Ok, for anyone following my other topic, here is the issue I have now-- I am convinced that my timing belt is off by a tooth. Now, when counting the cogs between the timing markings, do you count the teeth on the belt? Or do you count the valleys where the teeth on the cam gears sit? I was under the impression you count the teeth on the actual belt, and using that method, I get exactly 39 from cam to cam, and 48 from exhaust cam to crank. But if you look at this pic, the markings look off--

So if the timing IS correct, I dunno wtf to do. Because it certainly has all the symptoms of a car having the timing off (weak vacuum at idle (10" Hg), no power at all under 3000-3500 rpms, and the CAS is almost fully retarded).

I would like to know as well, thats pretty much exactly how my car is and my cas is turned all the way counter clockwise to hit 15 degrees. I was told to count the teeth, maybe it is the valleys though, anyone know?

Looks off to me.... But just that little doesn't seem like it would cause the problems it is.... I will get a tech to check out this pic and see what he says.... anyone else feel free to correct me here! I am new!!!

Chris,

Line the camshaft mark up where the belong and use the method I told you. Once you do that, look at the mark on the crank sprocket to see if it aligns pefectly with the notch on the lip of the oil pump. If it is not and your camshaft sprockets are aligned perfectly, then there's your problem. But, if they all line-up properly, you have either a bad CAS or other issues. My 4G61T is the exact same way. It idles at or 10hg and is kinda lazy until about 4000rpm and then it goes, but I'm too lazy to check the bottom end timing. Please do what I told you to do before you go crazy.

Sad to tell you and I posted this before, my lady's old sentra with CA18 did the same thing and the timing was perfect. i changed everything to include the harness and it still didn't help. I got frustrated, purchased my first standalone, and the problem was solved.

Dee

boost_boy wrote:Chris,

Line the camshaft mark up where the belong and use the method I told you. Once you do that, look at the mark on the crank sprocket to see if it aligns pefectly with the notch on the lip of the oil pump. If it is not and your camshaft sprockets are aligned perfectly, then there's your problem. But, if they all line-up properly, you have either a bad CAS or other issues. My 4G61T is the exact same way. It idles at or 10hg and is kinda lazy until about 4000rpm and then it goes, but I'm too lazy to check the bottom end timing. Please do what I told you to do before you go crazy.

Dee

Yes, I know, but they never line up properly no matter what. What I am wondering is, what part of the belt do you count between the markings? Because by counting the ribs on the belt between the markings, I get exactly 39 from cam to cam and 48 from cam to crank. I am trying not to flip out here or anything, but it's pretty frustrating.

boost_boy wrote:Chris,

Line the camshaft mark up where the belong and use the method I told you. Once you do that, look at the mark on the crank sprocket to see if it aligns pefectly with the notch on the lip of the oil pump. If it is not and your camshaft sprockets are aligned perfectly, then there's your problem. But, if they all line-up properly, you have either a bad CAS or other issues. Dee

The tech said that! Well, not word for word, but you get the idea. Find TDC (top dead center) Where all your timing marks are where they are supposed to be. This should be top dead center for piston 1... anyways which ever is off while the other is on is the problem. Either way... Just pull the T-belt off and start all over. Unless something is damaged.

dont worry about counting teeth!that will just get you confused.all you have to do is line up the marks!and yours arent lined up....so you need to redo it.

datsunboy wrote:so you need to redo it.

There's an echo in here!!!

the cam timming will be off if you use a non standard head gasket, of if you needed to resurface your head and/or block (realy, if the heigth of the cams relative to the crankshaft). Judging by your pics, you must have had to resurface the head and block, and use a standard height head gasket.

pd: just noticed your intake cam can also be 1 tooth off.

tineira wrote:the cam timming will be off if you use a non standard head gasket, of if you needed to resurface your head and/or block (realy, if the heigth of the cams relative to the crankshaft). Judging by your pics, you must have had to resurface the head and block, and use a standard height head gasket.

pd: just noticed your intake cam can also be 1 tooth off.

I am using a stock thickness headgasket, but I did have the head resurfaced. Only took off .0015" though. I can't imagine that making any bit of difference in where the marks line up. Although I have come to the conclusion that I cannot put this belt back on myself. Just toyed with it for 30mins and no matter what I couldn't get the cam gears to stop moving. I tried wedging screwdrivers, sockets, allen wrenches, etc in there. Nothing worked. So I need to find myself a competent second set of hands to help me out here.

ok ..seeing you are still not convinced..let me explain.

The camwheel dots should line up with the marks on the backing plate.The crank gear dot will line up with a mark in the block casting.

Orient the belt so that the lines put on them by the manufacturer line up with the dots on the gears. These line marks on the backing plate are visible in the photos you've provided.

The lines on the belt do not HAVE TO line up to the dots. But it is good practise to do it, as it makes 'tooth jumping' easier to spot.

Cheers.

dattodude wrote:ok ..seeing you are still not convinced..let me explain.

The camwheel dots should line up with the marks on the backing plate.The crank gear dot will line up with a mark in the block casting.

Orient the belt so that the lines put on them by the manufacturer line up with the dots on the gears. These line marks on the backing plate are visible in the photos you've provided.

The lines on the belt do not HAVE TO line up to the dots. But it is good practise to do it, as it makes 'tooth jumping' easier to spot.

Cheers.

Yeah, I didn't even use the markings on the belt when I put it on originally. I still need a second set of hands though.

its mountains/teeth on the belt.

niscort wrote:its mountains/teeth on the belt.

Well if that's the case, then my timing must have been setup properly as I got the proper amount between the timing marks. Am I correct? Or is it still possible to have the timing off even with the proper spacing between the marks on the gears?

If you have checked the crank mark , and it's lined up too, then it's ok.

After some ignition problems (Autronic dwell board), I was left with both cams being off one tooth. The cams roll towards the outside, if they are going to slip off one tooth, the intake cam ends up 5.4 degrees retarded, and the exhaust cam ends up 5.4 degrees advanced,

In single cam terms, this one tooth out on each cam increases the lobe separation by almost 11 degrees.

This basically gives very uninspiring power delivery.

Here's the pictures of the cam positions after the belt slipped.

Intake Cam

Exhaust Cam

Sorry can 't see the mark on the crank gear. But you can see the mark on the bottom left.
Modified by dattodude at 8:44 PM 6/2/2006

Chris, from the pictures, I'm about 90% sure your cam timing is off. Something that I always messed up was to place the dot on the cam gear on the wrong side of the 39th mark. Look VERY closely at the picture that niscort posted. It's 39 teeth (high points on the belt) BETWEEN the timing marks. Make sure you don't include the timing marks in your count.

my OEM belt has markings at both cam gears and I think the crank gear too - line em all up, and you're done. I agree your 2nd pic looks to be definatelly off! I don't even see a mark on the belt in the first pic but that might just be from it rubbing off.. ?

If your belt has stripes to mark all 3 positions like mine this should be a no brainer, if it doesn't.. ugh! good luck

its a no brainer anyway....dont need marks on the belt.line up the marks on the cams and the crank....and put the belt on!simple as eating pie ( tho maybe a big pie, as you'll need a second set of hands to make it easy )

tineira wrote:the cam timming will be off if you use a non standard head gasket, of if you needed to resurface your head and/or block (realy, if the heigth of the cams relative to the crankshaft). Judging by your pics, you must have had to resurface the head and block, and use a standard height head gasket.

pd: just noticed your intake cam can also be 1 tooth off.

This is not true on this application. I think a lot of us are using aftermarket headgaskets, decked blocks and resurfaced heads as well as aftermarket cams and still don't have a problem at setting the cam timing. If you set it wrong, this will happen. You don't need to have marks on your belt to set the cam timing as well. You either will set it right or set it wrong, hence the reason why we're having this discussion.

Dee

HOLY PHUKING $HIT. The car is QUICK now! A buddy and me redid the timing belt today. It took two sets of hands and several zip ties, but we got it on. Took it for a quick test drive and it pulls HARD now. Boost comes on sooner and driveability under 3k is vastly improved. Big thanks to all you guys who helped me out!

PS- The teeth on the belt were correct the first time. I didn't think it was possible to have the correct number of teeth between the marks, and have the timing still be off. I find that very interesting.

c-rad wrote:HOLY PHUKING $HIT. The car is QUICK now! A buddy and me redid the timing belt today. It took two sets of hands and several zip ties, but we got it on. Took it for a quick test drive and it pulls HARD now. Boost comes on sooner and driveability under 3k is vastly improved. Big thanks to all you guys who helped me out!

PS- The teeth on the belt were correct the first time. I didn't think it was possible to have the correct number of teeth between the marks, and have the timing still be off. I find that very interesting.

Outstanding! Have fun and be safe.

Dee

congrats Chris!

datsunboy wrote:its a no brainer anyway....dont need marks on the belt.line up the marks on the cams and the crank....and put the belt on!simple as eating pie ( tho maybe a big pie, as you'll need a second set of hands to make it easy )

I agree counting cogs is more of a check to make sure it went on right, line everything up with the marks put the belt on . I do remember having to lightly turn one of the cams with a open end to get it to sit just right with no slack. Never used zip ties and i hada do it alone, take your time don't touch the cam lobe with the wrench

Damn, 10 year necro posting! Glad to see you're searching though!

Ha! I did a CA timing belt the other day. Its been 7 years but I didn't even have to look anything up. Guess I've done it too many times!