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mk2

1.2 or 1.4 TDI injection timing checks with vcds?

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Curious to find out how many people have checked their injection timing deviation using VCDS or other diagnostics?

I've been reading various sources that the cam belt replacement on the 3L or tdi lupo is a very critical endevour where you need to use locking devices, pins and odd paraphernalia. Rubbish.

I did a 1.4 AMF the other day, and besides knocking up a fork to hold the tensioner in place, just used basic tools and a torque wrench. You really don't need them. The trick I think I've found is to use measuring block 4 item 4 which tells you the deviation from normal for the injection timing. Should be zero, but when i checked it before starting work, it was -1.2 (late). Some people reckon about +2 is the best setting. So easy to change just by loosening off the 3 cam bolts, turning a fraction by leaving the engine in gear, rolling car and tighten up again. Then start and check.

Has anyone checked theirs? Curious to know what figures people are seeing. You need to check it with a fully warmed up engine under no load at idle.

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My 1.7 sdi knocks it tits off and is quite obviously over advanced.

 Cambelt was done prior to me buying it at an independant (non VAG) and i guess the tech has just locked the cam and pulley up.

Ive always used locking tools to set cam timing bob on, pump timing is obviously different entitiy and computers drag us away from using the trusty Dti in rotor head.

Have put it on VCDS and timing graph shows it as being so far advanced its not showing on screen

 

Used the following to check:

https://www.ross-tech.com/vag-scope/TDIGraph.html

sdi's are on there.

 

Im guessing measuring block '+2' is simlar to being closer to green line/davanced.

Edited by ELVIS

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5 hours ago, ELVIS said:

timing graph shows it as being so far advanced its not showing on screen

oh. very very knocky then?! probably starts instantly though.

should be about 50% from memory (hot engine).

the sdi is a pain, but relatively straight forward to do. cam cover off. loosen off the front three pump bolts (just a bit!), the back one also, loosen the 4 injector supply pipes (a bit!) then tap the pump forwards a mm or two to retard. re-tighten (all eight) and then check again. I'll do a check on one of my SDIs and get a screen shot of what you should see, when I get a mo.

Edited by mk2

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New to Lupos but engines an engine. Can’t get my head around SDI’s though, basically an IDI with an ecu that doesn’t really do much  😀

 IDIs I do by ear then show off and check with a dti. 

Advance till it knocks, then back a bit! Lol. 

Will let you know how I get on chap. 

Edited by ELVIS

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Yeah I tried all that too. The ECU basically does the fuelling map and injection timing, as it's drive by wire. Inside the injection pump there's a servo which replaces the throttle cable (which moves the injection plunger sleeve, controlling each squirt), and a solenoid which is provided with variable power to vary the start of the injection pulse. Everything else is pretty much old skool. There's a pick-up on injector 3 which looks for the beginning of the pressure wave to tell the ECU where the timing is- which it uses as a reference. So you can nudge the injection pump one way or t'other to tweak the timing, which the ECU will spot and then try and compensate for... so it doesn't work. I worked out that you need to adjust the static timing, so when hot no load idling, it is right in the middle of the adjustment zone. Let the ECU do its thing... :)

 

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