Timing the MKIII 2.0 by tdogg74

11 minute read

Timing the MKIII 2.0

Courtesy of tdogg74 @ http://forums.vwvortex.com

August 27, 2010

I'm mainly writing this because I am tired of seeing the same questions every week. Figured I would write up a little DIY, the way I do it. (the quick and painless way). Now, I own/operate an OBDII ABA, so I'm assuming this works on an OBDI ABA as well. As for MKIV's....no clue. Im sure the DBC motors can go off this, but not the DBW motors.

The tools I use are simple:

*Adjustable wrench (for the tensioner nut and camshaft gear nut)

*Small needle nose pliers (to use as a spanner wrench to tighten the tensioner)

*Long flat head screw driver (to pop the clips on/off the distributor cap)

*Flash light (for near-blind, old ****ers like me)

I use these because they are very basic tools. They should be in the tool bag that should be in each and every one of you's hatch/trunk. (You are driving a VW, remember?)

Ok, now I'm going to go through and explain this, step by step, and it's going to make it look 10x harder and time consuming than it really is. I'm also going to go through a few different scenarios I see posted, and get some facts/fiction out of the way.

Most of the time, a post is made complaining of either:

Q: "I just did the timing belt and the car runs real weak/strong on the low end, but runs weak/strong at higher rpms."

A: The reason for this is that you slipped the belt over the cam gear either 1 tooth retarded (no low end, lots of top end) or 1 tooth advanced (lots of low end, no top end). Each tooth on the cam gear represents (appx) 8* of timing. From experience with my own motor, the |0| timing mark is pretty confusing because it's not 100% accurate for setting the timing. Example So, just keep this in mind when you get everything buttoned up.

or

2) Q: "I just did the timing belt and I get a CEL (P0341)."

A: The reason for this is that the tip of the distributor rotor is not properly aligned to the timing mark on the distributor, like this. The CPS (camshaft position sensor) is looking for the copper part of the tip of the rotor to pass by at a certain time. This is so that the ECU knows when to fire the injectors. If the timing is off, and the ECU does not receive the signal at the appropriate time, it will essentially go into a "limp mode". This limp mode retards the ignition timing to a safe 12* BTDC, and also fires all four injectors all at the same time as opposed to a 'sequential' firing pattern. An immediate loss of power is felt, along with a CEL with a P0341 code that will not go away until the timing is corrected, and the code is manually cleared with a scanner.

*Note #1: It is entirely possible to have the rotor off by a very small margin on either side of the TDC mark, and still run correctly. Motronic ignition is self-adjusting in that it is adaptable to keep in time. An example would be a timing belt stretching over time. It stretches to the point where the ignition cannot adapt any longer. It will pop a CEL and throw you into limp mode until the situation is fixed.

*Note #2: The flip side to this is a new belt is installed and no matter what, the rotor is off by a bit. Advancing/retarding the intermediate shaft pulley moves it too much. At this point, it is suggested to re-phase the distributor. This procedure includes loosening the fork nut that hold the distributor in place and twisting the unit clockwise or counter-clockwise until both line up. It is difficult to do on an OBDI motor because there are two pins keeping the distributor from twisting. Remove them. OBDII's, or at least on my motor, I had no obstructions keeping me from twisting the distributor. Again, this is a last ditch effort to time the distributor...most of the time you don't have to do this.

So now that we got the two major questions answered, lets get on with timing the motor. I'm going to take this through with you from scratch....like if you were replacing a timing belt. For this, you will use the adjustable wrench to loosen the tensioner pulley and slip the belt off the camshaft gear.

Align the crank shaft to TDC

First we will align the crank. Most guys would put a socket on the crank pulley and turn the motor over that way. I got an easier/faster way. Jack up the passenger side of the car so the tires is off the ground. Put the trans in 3rd gear. Now grab on to the tire and rotate it. Take it easy, because the compression of the motor is going to make it a little difficult to turn. 3rd gear in an O2O trans is pretty much a 1:1 ratio. Ok, so rotate the crank (by turning the tire) until the notch on the lip of the pulley lines up with an embossed arrow on the lower timing belt cover. Example 1 & Example 2. The Bentley manual instructs you to use the markings on the fly wheel. But that, again is confusing because the prominent mark is NOT the TDC mark....it's a small dimple that is very difficult to see. And what if you upgrade your flywheel like I did, and no longer have that mark? Use the marking on the crank pulley. It's easier and faster.

Align the distributor (intermediate shaft pulley)

Once the crank is TDC-set, now we have to get the IM shaft pulley aligned. This is easy to do as well. First we remove the distributor cap. (take note of which side is front.) Now, take the long flat head screw driver and **CAREFULLY** pry back the retardedly fragile clips off the distributor cap. Take your time with this and don't pry the clips back too far. If you do, they WILL snap off. (I have a fix for this, which I will explain later.) So with the cap off, you should be able to, with your finger, spin the rotor around. You will see that the intermediate shaft spins as well. Very simply, align the rotor to it's TDC mark.

Align the camshaft gear

Take the adjustable wrench and SLOWLY align the marking on the gear to the plastic timing marker behind the gear. Example. Just get it lined up exactly to the marks...the belt probably won't slip on at exactly on that mark, but it's a starting point.

Slipping on the belt

At this point we have all 3 aligned properly. Now comes the tricky part: getting the belt over the crank gear and over the int. shaft pulley without messing up the int. shaft pulley's timing mark. So, take our left hand and grab onto the belt to the left of the crank pulley. Take your right hand and grab onto the belt where it comes out, right above the int. shaft pulley. Very carefully, with your right hand, maneuver the belt to sit on the gear. Try to keep the rotor timed to the mark. Now with your left hand, you can easily maneuver the belt over the crank gear. You will be able to tell when you have all the slop between the crank and int pulley gone. You are basically going to be moving the int. pulley to get the belt over the crank gear. As long as the belt slips over the crank gear, with the rotor still timed, you are set. Now, if you screw this part up and get the belt over the gears, but managed to move the rotor off its mark, here's what you do. Still holding onto the belt with both hands, keep the tension of the belt on the int. pulley, but with the left hand, gently push down and finagle the teeth of the belt over the crank gear, letting the int. pulley move in whichever direction, until the belt is on the crank gear. It's a LOT easier than it sound, but you will completely understand once you are doing this.

Now, keeping the belt tight, let the belt slide through your right hand up towards the cam gear so you can start the belt over the camshaft gear. It's either going to slip right over, or, you are going the have to move the gear with the wrench to get it to go. If its the latter, simply keep grab onto both ends of the belt with your left hand, grab the wrench with your right and move the gear until its in the position for the belt to slip over. {It's a PIA, but its all you can do if you're alone.) Its usually just a small adjustment...slide over the belt.

The tensioner

At this point now, you got the belt over the crank, int. shaft pulley, and camshaft gear.....and hopefully the distributor is still on the TDC mark. Lets tighten the tensioner now. The tension is for taking up the slack on the back side of the belt. There are the old style tensioner (1993 thru mid-1997), and the new tensioner with a self adjusting dampener (mid-1997 thru 1999). The dampener automatically picks up the slack and keeps the tension as the belt wears. Carefully work the belt over the tensioner. Once in place, you will need to tighten the tensioner. You do not need the VW specialty spanner wrench to do this....I use my small pair of needle nose pliers. Works just as good. So we tighten the tensioner with the needle nose pliers with our left hand as we tighten the tensioner nut with the adjustable wrench with out right hand. DOne and done. You do NOT want to tighten the tension too tight. If you do, it will howl really loud. You just want it tight enough so it doesnt back out. As for the belt, you want to be able to twist it, between the camshaft gear and the int. shaft gear NO MORE THAN 90*. Your belt should be nice and snug on both sides of the camshaft gear. At this point you wan to put your distributor cap back on.

For those of you who were unfortunate enough to snap off one or both clips that keep the cap attached to the distributor, here is the quick and easy solution: 2 zip-ties. Most of the time (most, not all) the clips snap off so that even though they are no longer attached tot he dist. base, you can still hook them under the base lip and still be able to snap the top part over the cap like its supposed to. What remains is the clips not being on very strong. The vibration alone would knock them loos. So, you attach the ends of both zip-ties to make one long one. Wrap it around the mid-section of the clips, and cinch it tight. Viola! Problem solved.

SO thats it. Sounds like a LOT of work, but honestly, that was all just 5 minutes of work. Once you do it a couple of times, it gets easier and easier. I hope this helps to answer MOST of the questions out there. Consider yourselves fortunate these motors are so fricken easy to time.

Trav