Hard starting alh

thompsoncustom

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Nov 15, 2017
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iowa
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bora
Rebuilt my turbo and changing out the timing belt, glow plugs, motor mounts and so on.

Now my cars doesnt want to start worth a crap. Checked timing when I got done and it was within range but in the bottom side of the graph so I moved it up to the top side but still not any better.

IQ at idle is between 7 and 8 I have pp764 injectors so I was thinking moving it there might help instead of 4, tho it might have helped a little it's hard to tell if it did anything.

Car always started great before even at -10 if you cycled the plugs twice it started good. Now at 30 above it turns over quite a bit before finally starting.

Any advice?
 
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WildChild80

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May 30, 2016
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2001 Jetta TDI 2000 Jetta TDI 2000 New Beetle TDI ALL 5 speeds
My 01 TDI was hard to start, sometimes seemed like it was trying to run backwards... pretty sure it was cam timing, had a bogus cam lock tool. When you had everything at zero, did it start or did you have to move your IP to get it started after the timing belt change?

The graph shows you IP timing, not cam timing, only was to check that is set the crank at TDC and put your cam lock tool in

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[486]

Top Post Dawg
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MN
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02 golf ALH
another vote for cam timing, when mine was retarded to just before where the valves should hit (11 flywheel teeth, iirc) it took a lot of torching the intake manifold to get it to even start
 

thompsoncustom

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Very well could be cam timing when I got done doing the timing it was dumping fuel into the exhaust i believe maybe from the exhaust valve being open. It would start but I did adjust the iq right away to make up for the fuel.

I dont think anything moved at all but if the cam wheel takes as little adjustment as the IP than a mm goes a long ways.
 

WildChild80

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Very well could be cam timing when I got done doing the timing it was dumping fuel into the exhaust i believe maybe from the exhaust valve being open. It would start but I did adjust the iq right away to make up for the fuel.

I dont think anything moved at all but if the cam wheel takes as little adjustment as the IP than a mm goes a long ways.
Did you use a cam lock and did you knock the cam sprocket off during the timing belt job?

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thompsoncustom

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No I did not use a lock tool on the cam. No the sprocket did not come off or even appear to move, painted cam sprocket tho.
 

Nero Morg

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OR
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2014 A6 TDI, 2001 Jetta TDI, 2014 Passat TDI
No I did not use a lock tool on the cam. No the sprocket did not come off or even appear to move, painted cam sprocket tho.

You can't do that with these engines. The way the timing belt is designed, as you set the tension, the injection pump sprocket and cam sprocket are supposed to rotate as the belt moves to the tensioned position. Then, you are supposed to torque the cam and fuel pump sprocket. Doing it the way you did, will end up in the cam or injection pump being off.
 

Nero Morg

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Set the timing like you should. You don't have to take the belt off, but you'll need to set the crank at its timing mark, loosen the tensioner, loosen the cam and fuel pump sprocket, insert the injection pump pin, insert cam lock, set tensioner, then torque pump and cam gears. Bar engine over once, make sure all timing points are lined up.
 

turbocharged798

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99.5 black ALH Jetta;09 Gasser Jetta
Wondering how you rebuilt the turbo too. They are assembly balanced which makes them almost impossible to take apart and have the balance stay in tact.
 

thompsoncustom

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iowa
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bora
Well hopefully being off the pistons didn't touch the valves but it sounds fine when running.

I will buy the right tools for the job and redo the timing before I drive it again, thanks for all the help I have read a complete guides on it now and see where I went wrong.

As far as the turbo rebuild goes, your normal rebuild parts plus a seal plate and exhaust turbine & heat shield(was not straight) I'm sure it's not perfectly balanced but it cant be any worse off than it been for the last 20k miles.
 
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Nero Morg

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Well hopefully being off the pistons didn't touch the valves but it sounds fine when running.

I will buy the right tools for the job and redo the timing before I drive it again, thanks for all the help I have read a complete guides on it now and see where I went wrong.

As far as the turbo rebuild goes, your normal rebuild parts plus a seal plate and exhaust turbine & heat shield(was not straight) I'm sure it's not perfectly balanced but it cant be any worse off than it been for the last 20k miles.
Just as a note... Gotta be careful with turbos and rebuilding them. Very slight out of balance really means a lot at 50k rpm turbo speed.
 

thompsoncustom

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iowa
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bora
Agreed that's why I replaced the exhaust wheel was kind of surprised it was still in one piece with as bad as the stock one was.
 

turbocharged798

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Ellenville, NY
TDI
99.5 black ALH Jetta;09 Gasser Jetta
The thing the balance is now totally out since you have a new part on it.

Most turbos on the market are component balanced which means each part is balanced on a machine. The hope is that once the parts come together then the whole assembly should be balanced.

The VNT15 used on these cars is a oddity as its assembly balanced. This means that the parts before they get bolted together are NOT balanced. Once the rotating assembly is together, it is put on a VSR balancer and then balanced. This is actually a better way of doing it because the end balance will always be better BUT you cannot service it without re-balancing. Garrett themselves said not to take them apart and won't sell parts for it.

That is in a nutshell why rebuilt turbos do not work well with these cars. Maybe you got lucky and the balance is good, who knows. It might last 300K miles, it might blow up tomorrow. Its a crap shoot.
 

thompsoncustom

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Well thanks for the help guys got the tools and reset the timing the right way so I'm sure that it's all in time.

Starts better but still not great or as good as it used to.

Was -12 this morning so I figured I'd see if it would start cause it seems to struggle around zero where it always used to start even at -20. This morning it would not start even if I cycled the glow plugs twice or 3 times so something is still off probably need to tweak the iq some more.
 

wonneber

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Oct 12, 2011
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Monroe, NY, USA
TDI
2014 Jetta Sportwagon,2003 Jetta 261K Sold but not forgotten
When it's that cold I use wait a few seconds after the GP light goes out then I crank it.
Mine took 3 tries iIrc back then.
Don't recall it getting that cold more then a very few times.

Several years ago I finally decided if it's below 20F I'm just going to use my gas car.
Not as tolerant of the cold as I use to be and the gas car heats up faster. :(
 
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