Need assistance verifying the timing is set

[Kevin]

Car: Nissan 2005 Altima 2.5 A/T

I just did a head gasket on this vehicle. I’ve done head gaskets on Civics before, and this is my first Nissan. I bundled everything back back together and now it starts, but will surge 3 times and then die. If I give it gas, it’s rough until about almost 3k where it smooths out, but if let off the gas, it will die.

I checked my vacuum connections and everything seems to be in order. I also did this “idle relearn” procedure but that did nothing.

Symptom:

When I took off the cams, I made my marks on the sprockets and chain to make sure they lined back up. When the cams were removed I was holding them on via zip ties. But when I installed them the chain did fall. However I’ve seen multiple forum posts saying it cannot fall off the bottom pulley so it should be fine.

I remove the timing cover and compare it to the manual. Everything looks lined up. However when rotating the engine, at certain points the chain dips and there is slack. These videos show it all.

Any ideas? Thanks!

Topic

[Andrew Phillips]

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[Andrew Phillips]

Your timing is advanced one tooth. You need to reset the chain, probably the exhaust cam.

[Kevin]

[quote=”cap269″ post=134770]Your timing is advanced one tooth. You need to reset the chain, probably the exhaust cam.[/quote]

The manual is located at:
http://www.nicoclub.com/FSM/Altima/2005%20Altima/EM.pdf

I believe you, but how is it wrong? I have 12 links and everything lines up like the manual says. How could it be off?

Sorry I’m a bit lost by being “advanced one tooth” If I need to correct the chain over a tooth on the exhaust sprocket, which way do I go? Also it seems like there would be more either 11 or 13 links in between depending on which way I correct it. The manual clearly shows 12 links, unless I’m counting wrong on my marks?

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[Andrew Phillips]

Regardless of how you set your marks or counted the links, the valve timing is off, no question in my mind. During cranking, fire is supposed to occur at or near TDC. If the base timing is off, at crank it may still be close enough to start the engine (as in your case) but as soon as the engine starts and the computer takes over control and attempts to continue advancing the timing (as it is programmed to do), the timing goes too far out of spec and the engine stalls. Try retarding the exhaust cam by one tooth. Advancing = in the direction of normal rotation, Retarding = in the counter direction of normal rotation.

[Andrew Phillips]

Here is a video from ScannerDanner which demonstrates this problem. It is a different engine from yours, so lining up the chain will be different on your engine, but this should illustrate the situation for you.

[Kevin]

I’ll monkey with this. Do you think I have to take off the lower timing cover and make sure the chain is seated correctly? I never removed the lower cover because I wasn’t replacing the chain. Wondering if it fell a link on the bottom or something.

I’ll watch the scannerdanner video but have to hit up the junkyard for something else before they close.

So the solution is to retard the exhaust cam by one tooth, just move the chain over the counter direction of the normal rotation?

[Andrew Phillips]

The solution is to verify the correct placement of the timing chain, yes. Also, another video from ScannerDanner for more timing chain fun related to your problem.

[Kevin]

[quote=”cap269″ post=134789]The solution is to verify the correct placement of the timing chain, yes. Also, another video from ScannerDanner for more timing chain fun related to your problem.[/quote]

Ok, so I went through all the work to pull off the timing chain and reset it. I followed the factory manual and I saw exactly how it goes.

Line up crank pulley to TDC, white mark points at indicator
Cam sprocket pulley dowel pins face 9 o clock for the intake cam and 12 o clock for the exhaust cam
3 painted links of the chain. One goes at the bottom and the other 2 go on marks on the cam sprockets.

Bundled it all up. Mind you I had to drop the lower and upper oil pan, man it wasn’t bad but time consuming and tedious.

Went to start it, SAME FREAKING THING!!!!!! Surge 3 times then dies. WTF?!?!?!!!!!!!

I cleaned the MAF when I did the project just for good measure (CRC MAF cleaner). If I disconnect the MAF and start it, it will hold idle. Runs like poop, and won’t rev past about 2500 rpm, but will hold and stay running.

I paid justanswer.com for an “expert” and it was a shitty experience. He mentioned the MAF might be bad since there are no codes, and the behavior changes with it disconnected. Well a friend who has a car with the same MAF sensor, I swapped it, no go. Same thing.

He also mentioned I would get a code if timing was off a tooth, and misfire code if it was off more than a tooth. That makes sense to me. He also mentioned that there is a possibility of it jumping a tooth upon startup since I did not pull the fuel pump fuse to “prime the system” due to the oil tensioner, which makes sense to me.

So tomorrow I’m going to pull the cam cover and see if I have 12 links on the marks on the cam sprockets when the motor is at TDC.

ANY OTHER IDEAS? I’m ready to eat the cost I put into this and throw in the towel.

[Author]

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