[veganboyscout]

I am replacing my timing belt. First I put the engine at top dead center for cylinder 1. Then I marked the positions of the crankshaft cog and the camshaft cog with paint and removed the old belt. However, when I put the new belt on, the white lines on the new belt that are supposed to line up with the factory markings on the camshaft cog and the crankshaft cog, according to my Nissan manual, do not line up precisely. Additionally the belt seems to be a little loose on the side without the tensioner pulley, so it can't be tightened with the tensioner pulley. The white lines on the belts would appear to line up with the factory cog markings if I rotated the crankshaft cog one tooth clockwise before installing the belt, but if I did that then the lines I painted on the cogs before I removed the old belt would no longer line up. *What is more important to line up--the white lines on the new belt with the factory markings on the cogs? or the marks I painted on the cogs indicating their positions with respect to the block before I removed the old belt? And shouldn't the belt be tight on both sides?

 

[ron45]

In this picture the belt has no tension.

 

[BigJim]

The photo with the yellow mark is off, the white mark on the belt is supposed to go on the dot on that gear. That dot is to the left of the yellow mark. It looks like it was a tooth off to start with.

If this is an interference engine that could be bad. A few teeth off and you can bend a valve. I just checked, that is an interference engine so be very careful turning the cam with the timing belt off.

I know on a few cars I have worked on, if you don't lock the cams so they don't move the tension from the springs on the valves against the high points on the cam will rotate the cam or both, so they need to be locked in place. Do you have a factory manual?

Here is a diagram of your timing belt replacement. Just be sure the white marks on the belt are dead on the tooth with the dot or indention or your car is not going to run right or at all.

 

[veganboyscout]

BigJim, yes, I have what is called a "Service Manual" published by Nissan.

It sounds like you're saying I should trust the white lines on my new belt, not the yellow paint I used to mark the positions of the crankshaft and camshaft before I cut the old belt off. Apparently I did not have cylinder 1 at TDC as I thought I had, when I applied the paint and cut the belt.

While studying a diagram in the book more closely, I just realized that I'm using the wrong mark on the camshaft pulley to position the line on the belt! I'm supposed to use one of the circles under a tooth, not the arrow under a space. That would make more sense.

I'm not sure how to get the cam and the crank positioned where I want them so I can line the marks up correctly, without getting them out of sync and damaging the valves, but I think that is what I have to do.

I'll rotate the crank until the correct mark on the cam is at the top and the mark on the crank is about where it should be and then see if the lines match up.

 

[BigJim]

BigJim, yes, I have what is called a "Service Manual" published by Nissan.

It sounds like you're saying I should trust the white lines on my new belt, not the yellow paint I used to mark the positions of the crankshaft and camshaft before I cut the old belt off. Apparently I did not have cylinder 1 at TDC as I thought I had, when I applied the paint and cut the belt.

While studying a diagram in the book more closely, I just realized that I'm using the wrong mark on the camshaft pulley to position the line on the belt! I'm supposed to use one of the circles under a tooth, not the arrow under a space. That would make more sense.

I'm not sure how to get the cam and the crank positioned where I want them so I can line the marks up correctly, without getting them out of sync and damaging the valves, but I think that is what I have to do.

I'll rotate the crank until the correct mark on the cam is at the top and the mark on the crank is about where it should be and then see if the lines match up.

The sprocket with the yellow paint is one tooth off. no matter where you marked the old belt you need to put that white mark on the belt right on the tooth with the dot. Don't rotate anything without the belt on, except that gear with the yellow paint, just move the gear one tooth.

I can't see the other gear to tell where the timing mark is. It can be in the form of an arrow or a dot. You can remove the spark plug on number 1 cylinder and insert a wooden dowel or screw driver to see if #1 piston is indeed at the top of the cylinder.

One more thing to be aware of, when you release the tensioner to tighten the belt, make sure the timing marks on the belt and on each gear are still where they need to be. Sometimes tightening the belt will cause the belt to jump a tooth. No matter where your marks were on your old belt, make sure the dots on the gears and marks on the new belt align. Also make double sure you have the right belt.

 

[ron45]

If the belt had the right tension the marks would be aligned.

Look at the tooth to the right of the yellow line and you can see the belt is not touching. This means there is not enough tension.

 

[huesmann]

Does your crank cog have a keyway?

 

[BigJim]

Did you get your car running yet?

 

[veganboyscout]

Yes, I did get it running! Thank you for steering me in the right direction. I was in fact using the wrong factory mark on the camshaft pulley, so things were not lining up. I didn't even realize there was more than one mark on the camshaft pulley because they are not so easy to see. Once I used the correct mark, everything started to make sense.

Huesmann > My crankshaft pulley does have a key, yes. The camshaft does too according to the diagram.

I should say it runs fine, when it runs. Now I’m having trouble with it starting. It seems to be getting flooded very easily. I’m not yet sure if it’s lack of spark or some issue with the fuel injectors or sensors or just the cold. I also notice when it does start I have to hold my foot on the throttle until it warms up to keep it from dying. I didn't used to have to do that in previous winters, so the idle seems off or a sensor or the computer is bad.

Spark plug wires are hard to find for this engine, so I’ve kind of had to improvise a little. First, I'm going to test for a spark and go from there.