I need timing belt help

[dmitch31]

OK guys, here's my situation.

I've just changed my timing belt, and the engine still won't run, so I've got some questions. The reason I changed my timing belt was because it appeared that it had stretched and slipped.

First, to find TDC, I lined up "the mark" on the flywheel. Everyone keeps referring to it as "the mark" so I just want to make sure we're all talking about the same thing. On my flywheel, the mark I saw that I assumed was TDC was a white + sign. My Honda Service Manual just says "white mark", so I'm assuming that I was right on. Am I right with this? I also verified that the number 1 cylinder (the one closest to the belts) was at TDC because I had very gently put a small screwdriver in the spark plug hole that I could use to "feel" the position of the piston when it came up to the top. That along with the white + sign on the flywheel seemed to indicate TDC.

Also, I positioned the cam sprocket so the UP arrow was pointing up and the two marks on the opposite sides of the sprocket lined up with the top of the head. Then I put the timing belt on and put everything back together. The belt went on very tightly. To me it seemed that it would be very difficult to get the belt on a tooth or two off because if you keep the cam sprocket in the right position and the flywheel on the TDC mark, then the belt will only go on one way. To have the belt be a tooth or two off would be to move either the camshaft or the crank out of the correct position.

My second question would be regarding the "dot" on the crankshaft gear. The how-to on the site says that the dot on the crankshaft gear is supposed to be in the up position. When I put my crankshaft pulley back on, the dot was not up, but rather it was down at about 5:00. If I would have turned the crankshaft to where the dot was up, then I would no longer have the white + mark lined up indicating TDC. It seems here that I can't have the crank in a position where the dot is up AND the white + sign on the flywheel is lined up with the mark. What I'm wondering is if the white + sign on the flywheel is TDC and it is lined up with the mark, then what difference does it make where the dot is on the crankshaft gear? What am I missing here? Thanks for your help.

[azazel_18_2]

You didn't really tell us much about your condition. Did the car stop running and then you changed the belt or did it run and now that you changed the belt it doesn't run? Did it jump time with the old belt? It is very easy to get the new timing belt one tooth off. With the new tbelt on check your compression. Either it will have good compression or you have low compression and either your valves interfered with your pistons or you need to put the belt on right. I never ever looked at the white dot on the pulley. I just made sure I have the crankshaft at TDC and the cam on TDC. Give us a little more info and we will try to help.

[dmitch31]

I was driving the car, and it just stopped running, so now I'm trying to get it running again. I was just discussing this with a friend of mine and he thought that perhaps I have the timing on the cam 180 degrees off. Could it be that when the cam gear has the up arrow pointing up and the two marks are lined up that the number one cylinder is on the exhaust stroke instead of the compression stroke? In order to make sure that the cam is set right do I need to check both the cam markings AND look at the rotor in the distributor to make sure it is pointing at cylinder #1?

Also, I'll add that the timing belt did not break or come off. I just assumed that the timing belt was the problem. It was loose and had three teeth missing and I assumed that maybe it jumped a tooth or two causing the timing to be off. I guess it's possible that the belt was never the problem in the first place and the timing was right on and replacing the timing belt wasn't really getting at the source of the problem. Which, having a new timing belt on the car is not a bad thing, but I've just got to make sure I've got it on right, and if the car still won't run start looking elsewhere for the problem.

[azazel_18_2]

If the marker on the flywheel is at TDC and the cam gears marking show tdc then it is tdc. You have to sprin the crank pulley twice before the cam pulley fully turns once. If you had it 180 degrees out the flywheel marking would say tdc but the cam pulley would be upside down or 180 degrees off. If it had three teeth missing you probably have major problems. Make sure you have the timing belt installed correctly and give her a compression test. Give us some numbers but I bet you will have at least one dead cylinder due to bent valves/ and or holes in pistons. You can get a compression tester at walmart or about any parts store for about $20. Sad to hear about this. If you were closer I would help you out. I can get a good engine for about $75-100 if I pull it. Let us know the results. You should have a min compression of 100 psi per cylinder with a maximum variance of 20%

[Oldblueaccord]

On my car there two hash marks on the cam sprocket that line up with the head even.

Pretty much what azazel said only I can add...

TDC can be on the exhaust stroke as well. The piston pushes the exhaust out and the exhaust vavle is open. On TDC compression both valves are closed #1 cylinder.

Make sure at what you think TDC is the rotor points to #1 spark plug terminal.

Even if the belt is off a few teeth you still shouild get it to run but in wont have power like it should.


wp

[88accordSF]

try to make sure to minimize engine cranking while fixing this problem

easy to chew up a bit of valvetrain in the process of things..

[azazel_18_2]

I would only crank the engine over by hand until you are sure you have it right. If you feel any binding stop and go back and make sure you have it right.

[Blkblurr]

As long as your #1 pistion is up and you are at TDC on the flywheel and your valve trane cam gear is lined up with the head with the up indicator Up you are lined up correctly for installing the timing belt. a quict check is to look at the rotor to see if it's at #1 plug assuming the dizzy was not taken out and installed wrong. One other thing you should do. Once you have piston #1 all the way up, Slowly rotate the cam gear without the timing belt on it through one revolution to see that this engine is a non interference engine. You should hit nothing. This assumes that the engine has not been modified such as higher lift cams or a shaved head.

[azazel_18_2]

DO NOT DO WHAT HE SAID. I lost my t-belt at 70mph due to the tensioner locking up and it TRASHED my engine. It is an interference engine as in the pistons will interfer with the valves if the timing belt takes a shit.. Call Napa or any parts store or check out their website.

http://www.napaautoparts.com/masterpages/NOLMaster.aspx?PageId=430&Keyword=timing+belt&KeywordCat=Belt+-+Camshaft%2fTiming&VehCode=Y

Just make sure it is on right. If it is do a compression test and it will tell you what you need to know.

[MessyHonda]

DO NOT DO WHAT HE SAID. I lost my t-belt at 70mph due to the tensioner locking up and it TRASHED my engine. It is an interference engine as in the pistons will interfer with the valves if the timing belt takes a shit.. Call Napa or any parts store or check out their website.
http://www.napaautoparts.com/masterpages/NOLMaster.aspx?PageId=430&Keyword=timing+belt&KeywordCat=Belt+-+Camshaft%2fTiming&VehCode=Y
Just make sure it is on right. If it is do a compression test and it will tell you what you need to know.




my uncle had a 89 lx and the timing belt went off at a stop light and they put in a new belt and it lasted all the way to the junkyard.

[azazel_18_2]

They are interference engines though. Some people may get lucky and their engines not destroyed but there are few.

[MessyHonda]

They are interference engines though. Some people may get lucky and their engines not destroyed but there are few.


yeah....to be on the safe side i will say they are interference.....but ive been a witness. that the valves dont get bent.....or else why would they put valve reliefs on the pistons....might as well leave them flat

[Toneloc5145]

I can't positively say that the engine is or is not an Interference, but my experience, I had 22 teeth shear off my timing belt and my engine now runs better than it did before that happened. It started right up, after we got the timing right.

Also, when we were setting the timing, we rotated the cam gear while the crank wasn't moving and I didn't notice any contact between the valves and the pistons. I didn't hear, feel, or see anything that indicated there was contact going on.

[Blkblurr]

DO NOT DO WHAT HE SAID. I lost my t-belt at 70mph due to the tensioner locking up and it TRASHED my engine. It is an interference engine as in the pistons will interfer with the valves if the timing belt takes a shit.. Call Napa or any parts store or check out their website.
http://www.napaautoparts.com/masterpages/NOLMaster.aspx?PageId=430&Keyword=timing+belt&KeywordCat=Belt+-+Camshaft%2fTiming&VehCode=Y
Just make sure it is on right. If it is do a compression test and it will tell you what you need to know.
This is an age old debate and yes it is classified as an interference engine But and I will say this again it does not cause valve damage or hit the pistons at all no matter where in the engine cycle you are. This assumes that you have a completely stock engine. There is no luck about it. That's why I suggested he rotate the cam gear without the belt on when the lower engine is at TDC. This way he can prove it to all you non believers that you don't hit anything. I have built many engine assembly systems for the Honda plant in Anna Ohio where these engines were built. I know what I'm talking about and I have tried it myself when I rebuilt the cyl head on my SE-i.

[Blkblurr]

I can't positively say that the engine is or is not an Interference, but my experience, I had 22 teeth shear off my timing belt and my engine now runs better than it did before that happened. It started right up, after we got the timing right.

Also, when we were setting the timing, we rotated the cam gear while the crank wasn't moving and I didn't notice any contact between the valves and the pistons. I didn't hear, feel, or see anything that indicated there was contact going on.
That is exactly what I did and how I know for sure it will not hit anything. When valve damage occurs, it's because something else broke that caused the cam pully to lock up breaking the timing belt and sometimes the tensioner. People just assume the broken belt caused the problem. Of course you can get damage if you made engine mods that cause the valves to open more or get closer to the pistions.

[LX-incredible]

At TDC, loosen tensioner and rotate the crank CCW until the cam gear moves 3 teeth. Hold the crank and tighten the tensioner.
If the belt is still loose, you might need to push the tensioner in by prying on it and then tighten. Rotate the tightened belt a few revolutions and re-tighten using the normal method.
After tightening using that method, rotate CCW until the marks on the cam gear line up with the top of the cylinder head. The "UP" should obviously be just that, the pointer should be dead-on TDC. Never rotate the crank clockwise, especially when installing a belt, it will be off.

[Blkblurr]

After tightening using that method, rotate CCW until the marks on the cam gear line up with the top of the cylinder head. The "UP" should obviously be just that, the pointer should be dead-on TDC. Never rotate the crank clockwise, especially when installing a belt, it will be off.
Yep, keeps the tension on the correct side of te belt and loads the tensioner properly.