[CackInc]

So, about a year ago, I repaired my head (valves, timing belt, water pump, tensioner, etc.)

Everything went perfect, and it runs great. However, it doesn't always start on the first try. Sometimes two tries, sometimes seven. Cranks, just doesn't fire. And when it does start and is at idle, the idle jumps from 7-800, up and down. I also get a p0340 code all the time (camshaft timing sensor). I already changed the sensor with a brand new one, and checked the wiring. All looks good.

Again, she runs great, but something is off.

I just checked my timing marks on the cam and crank pulley. It's perfect. Took the valve cover off, and the marks on the cams versus the journal arrows look almost perfect, but I can't tell if I have sixteen teeth on the chain or not. I'm not an expert at that. Anyone know if that would be the problem?

 

[AndreasPassat]

Looks to me like the intake cam is retarded by one roller. Meaning there is 15 rollers not 16.
It's hard to say for certain because the picture is slightly distorted.
You need to get a picture directly in line of the camshaft, of both intake and exhaust.

 

[CackInc]

It's weird. I'm pretty sure I took both cams out with the chain still on, then put it back in without removing anything. I can't remember for sure. Anyway, that was before I knew about the 16 rollers on the cam chain. Did it better on the A4 I worked on.

Here's some better pictures... I hope.

 

[CackInc]

So, if I'm off by that one chain link, it would cause the issue I've been having? You think?

 

[PZ]

Your can chain tensioner is not extended at the top for the picture, so it looks like it's only slightly off, but it is off 1 tooth. Try rotating the engine clockwise and see if the CCT moves up and down. If it does not, the CCT is faulty and needs to be replaced. After 2 full turns, the cam mark on the exhaust cam should line up.

 

[CackInc]

Your can chain tensioner is not extended at the top for the picture, so it looks like it's only slightly off, but it is off 1 tooth. Try rotating the engine clockwise and see if the CCT moves up and down. If it does not, the CCT is faulty and needs to be replaced. After 2 full turns, the cam mark on the exhaust cam should line up.

I think it does move up and down like it should. I'll check again tomorrow. I'm not hearing and sound from the engine either, like if the chain were loose. But if it does move up and down, you think my CCT is ok? But I'm just off one tooth on the intake side?

 

[PZ]

If it moves up and down, it should be ok. Only turn the engine clockwise, if you turn it counter-clockwise, it compresses the CCT and would look like your picture. You are off 1 tooth at the intake side.

 

[CackInc]

If it moves up and down, it should be ok. Only turn the engine clockwise, if you turn it counter-clockwise, it compresses the CCT and would look like your picture. You are off 1 tooth at the intake side.

Yeah, I only turn it clockwise. Cool. I'll check again though. Looks like I'll be taking off my intake cam! Thanks!!

 

[PZ]

For the hard starting and inconsistent idle, adapt the throttle body. If that does not work, clean it.

 

[CackInc]

For the hard starting and inconsistent idle, adapt the throttle body. If that does not work, clean it.

What do you mean by adapt?

 

[AndreasPassat]

What do you mean by adapt?

Adapting the throttle body is essentially like a calibration sequence, so the ECU knows where the throttle valve/plate is at relative in degrees of position.
It can be done with VCDS software.
It might also be able to be done with a certain sequence of the ignition key, but I'm not aware of how to do it that way.
I always use VCDS.

Someone will chime in about this.

 

[Tomvw]

1. Disconnect the battery negative terminal.
2. Correct the timing chain error.
3. Reconnect the battery, switch the ignition ON, do not start, wait 1 minute then start it.
The TBA should automatically run when the ignition is first switched on.

 

[CackInc]

Should I clean the throttle body first? BTW, you guys are awesome! Thanks

 

[VAGguy]

Should I clean the throttle body first? BTW, you guys are awesome! Thanks

It certainly can't hurt to clean it and only takes a few minutes. I do it every 10-20k or so. Just for something to do. Most times, a good wipe around the throttle plate opening with a rag soaked with throttle bod cleaner is all it takes.

 

[CackInc]

Welp, everything you guys said to do worked. Starts on the first try, every time. It doesn't seem to have a weird idle, but I can't tell because now I have a misfire. Lol! Trying to figure that out now.

 

[CackInc]

To everybody who helped, thank you very much. My son and I figured out the misfire, and she is running amazing now. Throttle response is WAAAYYYY better, and it seems a lot quicker. And, no check engine light. Thanks again!!

 

[AndreasPassat]

So what was the culprit?

 

[CackInc]

The cam chain was off by one tooth. And then I cleaned the throttle body real good, and did the adapt cycle (or whatever it's called). The misfire was just a dirty connection to the spark plug.

 

[PZ]

Always glad to help.

 

[Tomvw]

Glad to see that you are happy.