so close to starting...

[KiLLeR2001]

Ugh. I'm going insane over here, my car feels so close to starting up. I have a fully rebuilt to stock specs SR20DET Redtop that I just put in my '90 Hatchback. The engine cranks, spark is present, and theres fuel. Oil pressure is built up and the lobes have oil on them. The only thing I'm left with is timing. I've done it over THREE times already. set the crank to the 2nd marking from the left, with the #1 piston at TDC and the lobes facing outward. Then setting up the CAS properly based on the frsport article (http://www.frsport.com/How-To-Set-Crank-Angle-Sensor--CAS--Timing-on-the-SR20DET-Engine_t_25.html)

The only thing that doesn't check in is the cam sprocket markings do not match up with the miscolored links on the timing chain. I ignored this because maybe the shop that did the engine just put the chain on without matching it to the sprocket markings.

I've already switched to another #62 ECU and the same outcome occurs... It just keeps cranking and cranking, sounds really close to starting though.

One thing I'm thinking is the battery. It's been sitting for a month without use, so maybe there's not enough amperage for initial startup? But the starter is still cranking the engine over, for about 15 seconds straight at one point, my other times have been 5 second intervals.

As far as fuel goes, stock 370cc injectors, stock FPR, stock fuel pump, the fuel pump primes up and I can hear fuel in the rail.

It must be something very basic and simple I'm overlooking.

Any help is appreciated, thanks!

:bigok:

[slider2828]

I wrote an article on how to redo timing without worrying about bottom link. Involves counting. Look it up... Dang sucks

[slider2828]

http://www.zilvia.net/f/showthread.php?t=145875

There is the link to how to do timing correctly, or pretty close to correctly, if you didn't drop the chain.

[KiLLeR2001]

Hmm, I think maybe I didn't crank the engine by hand enough? I just stopped when the #1 lobes were facing out and TDC was achieved at the 2nd marking from left?

Do I need to keep turning it over until the darker links match up with the sprocket markings at TDC?

[KiLLeR2001]

I think I found the problem, here are some pictures...

http://tehl33tsite.com/240sxdd/help/Img_1321.jpg

http://tehl33tsite.com/240sxdd/help/Img_1322.jpg

It appears the actual sprocket teeth are fitting into the gap between the links instead of actually in a link. My friend did take off the intake sprocket and said he put it back the same but now I'm thinking not.

The intake cam sprocket mating mark to the gold chain link is about 6 links away (not including the actual gold chain link making it the 7th link).

Keep in mind at this point the outer lobes are facing outward and the exhaust cam key is 12 oclock but the markings now on the crank pulley are far right from the actual needle marker that points to the marks on the crank pulley

[Big Bronze Rim]

If you have a chain that has the shiny links (I have seen some that didn't or you couldn't tell), make sure that you realize that they will not hit on the dots every revolution. I don't remember exactly but it takes someting like 7 revolutions for them to come into phase with eachother while pointing at TDC. It is easier to count links to confirm that you are correct. If your engine is at TDC in that Pic and the exhaust key is at 12oclock, then couting 20 rollers seems that your timing is correct. Are you sure you stabbed the CAS correctly?

[KiLLeR2001]

I think everything is fine its just the chain is HALF a link off the sprocket as you can see. So would I just take off the intake sprocket and rotate it a little to match up with the correct chain link so that from the 10oclock on the intake sprocket marking is 9 links between the link on the exhaust sprocket which is at 12 oclock (like it appears on the frsport page)

[KiLLeR2001]

Here's where im at now...

http://tehl33tsite.com/240sxdd/help/Img_1323.jpg

http://tehl33tsite.com/240sxdd/help/Img_1324.jpg

On the exhaust sprocket I've managed to put it on an actual link but the intake sprocket is still inbetween one... Also the lobe on the intake cam is pointing more towards 9oclock compared to the exhaust cam pointing at like 2olock as you can see in the second picture

Edit: Is there a special way to take off the intake sprocket or do i just wedge a screwdriver in one of the holes and go counter clockwise with the breaker bar. I'm really trying to be careful here because I know she wants to start and I don't want to kill her before given the chance lol... Also, whats the torque specs when putting the sprocket nut back on? Thanks guys.

[KiLLeR2001]

Alright. I managed to adjust the intake sprocket so that the cam marking tooth went into a link properly. and kept it at TDC with the lobes facing outward. My only question is now, how is the lobe suppose to be for the intake cam opposed to the exhaust lobe on #1?

The way it is now is the lobe on the intake cam #1 is more at 9oclock and the exhaust cam #1 lobe is more 2oclock. When I cranked the car over like this it sounded more like it wanted to start but still seemed off. I think the problem lies with the position of the intake cam (since it was tampered with) but I'm not sure, I'm still new to this whole procedure myself? Anyone have any advice to get the timing on par?

[slider2828]

No Man. It has to be 12 on the exhaust cam and 10 on the intake cam. IT MUST BE. Then 20 rollers in between. I sent you the link to the article about how to do it with pictures. Read it.....

[KiLLeR2001]

No Man. It has to be 12 on the exhaust cam and 10 on the intake cam. IT MUST BE. Then 20 rollers in between. I sent you the link to the article about how to do it with pictures. Read it.....

I've read the thread but I'm not understanding how the intake mating mark (10oclock) and exhaust mating mark (12oclock) can be 20 rollers apart from each other. They are exactly 9 links away from each other when in the 10 and 12 positions.

Do you mean for me to set the exhaust to exactly 12oclock on the mating mark and then the intake sprocket mating mark further left so that the gap inbetween the 2 marks is 20 links? And then hand crank it until TDC and the marks become 10 and 12 respectively?

I appreciate your time, I really think I'm getting closer to firing her up.

[johngriff]

Compression Test.

Now.

[KiLLeR2001]

75 45 55 30, my life officially sucks.

Could this be a timing issue at all?

[Z U L8R]

well......the compression's probably low because the valve timing is still off....or trying to start it with the timing off, your valves could have kissed the pistons just enough to not seal properly....

this would be a good time to call a friend who's rebuilt sr's before and have him time the engine, then i'd recommend a leakdown test before you put it all back together. leakdown test will let you know if any damage occured while the timing was off. gl man
Dave

[Big Bronze Rim]

You had it right before messing with it. It should be 20 rollers between marks - you are at 19 now. And yes, timing can potentially be affected by compression due to excessive overlap, however another result can be bent valves.

I've read the thread but I'm not understanding how the intake mating mark (10oclock) and exhaust mating mark (12oclock) can be 20 rollers apart from each other. They are exactly 9 links away from each other when in the 10 and 12 positions.

Do you mean for me to set the exhaust to exactly 12oclock on the mating mark and then the intake sprocket mating mark further left so that the gap inbetween the 2 marks is 20 links? And then hand crank it until TDC and the marks become 10 and 12 respectively?

I don't think you get it yet. You are not lining the mating mark up with 10 and 12 oclock. You are referencing the exhaust cams alingment key to 12:00. There should then be 20 ROLLERS between the dots.

[KiLLeR2001]

You had it right before messing with it. It should be 20 rollers between marks - you are at 19 now. And yes, timing can potentially be affected by compression due to excessive overlap, however another result can be bent valves.


I don't think you get it yet. You are not lining the mating mark up with 10 and 12 oclock. You are referencing the exhaust cams alingment key to 12:00. There should then be 20 ROLLERS between the dots.

Ah, I see what you're saying now. But 20 rollers is equivalent to 9 links separating the mating marks on the cams. But I did set the timing based on the mating marks on the cam sprockets and not the actual key on the cam itself.

Before cranking the engine over each time I would hand crank it to see if I had any trouble with the valves touching and it turned over fine without any troubles, no weird sounds or anything. Then when cranking with the starter it sounds like a normal engine trying to fire up but wont.

[Z U L8R]

cool, good precautions. once you feel comfortable with the valve timing, post the results of another compression test.
Dave

[slider2828]

Thirdly, the key tooth on each came should never be the in the middle of two chain links. It should always be in the middle of the link. Your intake cam I can see is in between two links which already tells me it is wrong....

Don't drop the soap I mean chain and compression test it.

O another thing is manually crank the crank pulley after you think you have got it. If you if you really got it right, the cam key tooth can and should mate with the correct gold and silver link on your chain at TDC. Might take awhile. Second thing is you need to crank it to make sure it the chain does not jump, trust me it can happen.

[KiLLeR2001]

I'm pretty sure I know what I've done wrong here. I only hand cranked it a couple times and since the lighter colored links weren't matching up I thought the timing was fubar from the start. So thats when I started messing with the intake cam. Now it's all a matter of adjusting it back to the way it was.

My only reference now I suppose is the exhaust cam correct? Should I wait till the lighter colored link matches up at the exhaust cam sprocket mating mark (at TDC) and adjust the intake cam accordingly?

What time is the lobe on the intake cam #1 suppose to be pointing at, TDC? 10oclock? 9oclock?

[slider2828]

10 oclock. Well the link shave to be 20 rollers apart either way....

[KiLLeR2001]

Here's where I'm at right now... 80 psi on the first piston...

http://tehl33tsite.com/240sxdd/help/Img_1327.jpg

http://tehl33tsite.com/240sxdd/help/Img_1328.jpg

At TDC, #1's intake lobe is about 8oclock which I think it not right at all. Judging by the pictures can anyone find a problem with the timing? The CAS is set correctly.

edit: It seems both the cams are off the exact same (too much counter-clockwise) (AT TDC SECOND MARK FROM LEFT). They are the correct amount of rollers apart but both cams need to be rotated clockwise so that the intake key is 10oclock and the exhaust key is 12oclock.

What's the best way to rotate both cams (CLOCKWISE) while keeping the crank at TDC?

[slider2828]

You loosen the cam bolts. There is no easy way to do it and don't be lazy just loosing some of the bolts. Loosen all the bolts, cause people snap cams this way. Keep rotating until everything lines up.

[Gjohnson7]

Man, it seems like you are making this harder than it actually is. I'm in the same boat as you and you just have to make sure you do it right or you will have issues.

The bottom line is you need to rotate the crank to TDC, place something down between the timing chain to make sure it doesn't fall. Remove the timing chain tensioner and start over. Make sure you use the directions in slider2828's posts above. It's really not that hard, but sometimes it takes more work then you would like.

[KiLLeR2001]

You loosen the cam bolts. There is no easy way to do it and don't be lazy just loosing some of the bolts. Loosen all the bolts, cause people snap cams this way. Keep rotating until everything lines up.

So loosen the cam bolt, then the bridge bolts holding the cam down? Then I'm assuming the cam will be able to come right out and I can rotate it however, correct? There won't be any tension on it or it wont spin around? Is it better to do one cam at a time or both at once?

Sorry for all the easy questions but I really don't want to make a simple mistake that could cost me my entire engine. Thanks.

[slider2828]

Killer, Just make sure you loosen all the bridge bolts holding the cams in place. PLease please follow FSM tightening procedures. Cause that is really going to kill your cam if not 100% of the time. The Cam bolt doesn't hold the actual cam down. Those have a key and it is locked. If you completely loosen both cams out via FSM there is no tension, just the chain will be a little bitch... But before this, try it this way. Don't need to line up the links, just do the 20 rollers as in he picture and make sure its TDC. Try that first before rotating everything like you think

[KiLLeR2001]

Killer, Just make sure you loosen all the bridge bolts holding the cams in place. PLease please follow FSM tightening procedures. Cause that is really going to kill your cam if not 100% of the time. The Cam bolt doesn't hold the actual cam down. Those have a key and it is locked. If you completely loosen both cams out via FSM there is no tension, just the chain will be a little bitch... But before this, try it this way. Don't need to line up the links, just do the 20 rollers as in he picture and make sure its TDC. Try that first before rotating everything like you think

Loosen the bridge bolts or take them out completely along with the bridges themselves?

As of right now (at TDC in the pics above) the intake cam key is pointing more towards 9oclock and the exhaust cam key is at 11oclock. I'm pretty sure if I move the cam (along with the sprocket) clockwise ONE LINK it'll be where it needs to be, and I need to do this to both cams so that they remain 20 rollers apart, however doing so will no longer match up the mating marks with the lighter colored links on the chain, but that pretty much doesn't matter anymore correct?

Thanks for the help so far everyone. ++++REP!

edit: What type of compression numbers am I looking for if I manage to get the timing right? Keep in mind the engine has never been started and obviously the piston rings have not sealed yet since everything is fully rebuilt.

[slider2828]

I would complete take them out, because you don't want to drop any bolts or washers into the motor. NOT RECOMMENDED hahaha....

He you know tdc mark is NOT 2 marks from the left man.... that is 15* before top dead center. Top Dead Center is two marks from the right. I would put it on Top Dead Center and Make sure the exhaust KEY (Key is the nipple thing that stops the cam gears from spinning on the cams) on the cam is at 12 Noon and the intake KEY is point around 10 and 20 rollers across.

Compression should be about 150 across the pistons. If you put in the CAS in correctly, the ECU will time it up itself.... Then you just put a light. But check compression first, that will tell you if you got it