Adjusting injection timing - really that easy?

[tdi_allan]

Used VAG-COM to check my injection timing recently (the TDI Timing plugin is great!) I found that my timing was advanced just barely out of the range in the graph. After consulting my Bentley and the forums here, it seems that adjusting injection timing is a pretty simple thing to so, once you get the hang of the minute movements involved.

I noticed that no one mentioned the injection pump locking tool, I assume you one would need that while tightening the pump sprocket bolts, is that correct? (Just what I need, more tools... /images/graemlins/smile.gif )

 

[brenner]

you don't use the locking tool when finetunig the inj.timing .as for the locking tool you can use a 6mm drill bit or bolt.also slightly advanced timing makes for easy starting in subzero weather.

 

[TDINJ]

It is pretty easy, but it is only a very (seemingly less than a hair width)movement that you make. To retard the timing, pully is adjusted counter-clockwise (toward the back of car). I think this is true - I've done it several times but not for awhile.

I would read the FAQ section and do a search, there is a ton of info on it.

There are three bolts you need to loosen (NOT REMOVE)while adjusting. They are the ones surrounding the center bolt - which you DO NOT want to loosen! I can't remember the ratchet size for the bolts but it is in here somwhere. If they are the original stretch bolts you should replace them with the non-stretch type. The center bolt should be torqued on very tight to begin with - but be careful you don't want the center bolt to loosen PERIOD.

Anyway, there should be a lot of info in the FAQs and other posts.

 

[tdi_allan]

brenner, my timing was advanced just outside of the graph, thus the need to adjust to "slightly advanced." thanks for the tip about the 6 mm drill bit also.

TDINJ, your points are well taken, the Bentley procedure says to rotate the pump shaft with a 22mm wrench on that bolt, I would think that the fine adjustment needed would not be in danger of loosening that bolt. At least I hope not :O

 

[brenner]

the 3 bolts are 8mm,the hex size is 13mm.if you loosen them you need to replace them if they are the stretch type.new bolts are 75 cents each at the dealer.

 

[jackbombay]

This won't mean much to you now, 55...82...60...77...50...90...63...70, but it will soon.

-Jack

 

[tdiflyer]

[ QUOTE ]
To retard the timing, pully is adjusted counter-clockwise (toward the back of car).

[/ QUOTE ]
When you're setting the timing, the sprocket position is fixed by the timing belt. What you actually move is the injection pump shaft (using the 22mm nut). So to retard the injection timing, rotate the shaft counter-clockwise. You have to use the big nut to restrain the rotation when you re-tighten the 3 bolts, but there's also help from the crankshaft friction through the timing belt, so it should be virtually impossible to loosen the centre nut doing this.
The required adjustment is very small, and you'll probably have to do it several times to get to the right setting. It gets tedious loosening and retightening all 3 bolts, but don't be tempted to leave any of them loose when you start the engine. Although one bolt will provide enough friction to turn the pump so that the engine will run, vibration can back the others out in a remarkably short time. They will exit the sprocket with considerable velocity. Please do not ask how I know this.

 

[DeafBug]

Also if you accidently move the nut too much that the pump can slip. You have a small window inside where the three bolts are. It can slip to the end and you may be screwed at that point. Don't ask me how I know this.

 

[jackbombay]

[ QUOTE ]
You have to use the big nut to restrain the rotation when you re-tighten the 3 bolts

[/ QUOTE ] I didn't, I did not want to loosen the 22mm nut and be screwed, I was able to tighten the 3 bolts without the engine turning over at all.

-Jack

 

[tdi_allan]

Thanks to all that have posted on this thread, especially to those that have taken the proverbial arrows in the back so the rest of us have an easier go of it. Because of this and other threads, I have the information I need to tackle my Jetta's injector timing after I finish my 40,000 mile maintenance this weekend. I'll see if I can post before and after vag-com results. Time to find a 22mm wrench! /images/graemlins/smile.gif

 

[brenner]

22mm wrench ?a 7/8 sae wrench will fit!

 

[DeafBug]

7/8 wrench is what I use all the time when doing timing belts. It came with the 251 piece tool set from Sears so why buy a 22mm when a 7/8 will do.

 

[tdi_allan]

brenner said:

[ QUOTE ]
22mm wrench ?a 7/8 sae wrench will fit!

[/ QUOTE ]

and DeafBug opined:
[ QUOTE ]
7/8 wrench is what I use all the time when doing timing belts. It came with the 251 piece tool set from Sears so why buy a 22mm when a 7/8 will do.

[/ QUOTE ]

Once again, excellent advice. I am pretty sure I have a 7/8" wrench somewhere. Thanks brenner and DeafBug!

 

[tdi_allan]

[ QUOTE ]
Thanks to all that have posted on this thread, especially to those that have taken the proverbial arrows in the back so the rest of us have an easier go of it. Because of this and other threads, I have the information I need to tackle my Jetta's injector timing after I finish my 40,000 mile maintenance this weekend. I'll see if I can post before and after vag-com results. Time to find a 22mm wrench! /images/graemlins/smile.gif

[/ QUOTE ]

Well, the 40,000 mile maintenance went well, but I didn't retard the injection timing yet (waiting for my snazzy hose clamp tool to arrive.) If there is anyone in the Chicago area that has time to give me a hand with this, I'd be happy to not only drive to you, but would include a quantity of your favorite beverages as a token of my apprecitation. I'll turn the wrenches, I just want a second set of eyes to make sure I don't destroy anything important. /images/graemlins/smile.gif Thanks in advance!