G40 Timing Issue...

[DKnight]

Well this old question rises again

ive just spent the day having a play with my car, to round things up.

My car is sluggish, not as fast as it should be with the mods it has

On start up it sounds rough, as put in another post, but then after a minute or so it picks up and its fine
It has a strong smell of fuel from the exhaust, and it is visual (as anyone at rolling road will have seen)
My fuel consumption is not bad at all, id say it was good even, so rules out any sensor issue, had it vagcom checked and they are all fine

So i checked the timing, and this picture shows what i have found and done today


Now the first pic is what everyone is telling me, and haynes, but i manually checked and when the piston is at its peak, the 2nd of the marks on the crank pulley is the TDC mark, i checked this with placing something in the spark plug hole, and at its peak the 2nd mark is that.

So that confused me to start.

So i moved the timing to the 3rd picture, and it ran much nicer, and pulled strong, and no signs of smelly fuel from the zorst, and it just sounded to run nicer...

I did reset the timing aswell after moving the belt.
The only down side from the 3rd picture, is the obvious fact that it is telling me its not timed correctly, and it did seem to get warm quite quickly...
But that may be down to the actual ignition timing not being right...

Im confused and wondered if anyone has any ideas?

[DKnight]

oh also, i did tihnk maybe the bottom timing pin, thing, that bolt on bit of metal might be bent and not lined up correctly...

[hayesey]

that's interesting.  There are lots of reasons why the mark might not be mega accurate.  Have you had the head skimmed too?  might make a difference if they've taken a fair bit off.  dial indicator on number one piston is the most accurate way of doing it, then needs a vernier to get just right.  glad you've finally found out whats going on, shame you didnt find that before the rr day though!

[DKnight]

head has been skimmed yeah, but ive far from fixed the problem yet, im no closer to knowing whats up!

[scotsjohn]

Fuel smell from exhaust's likely to be very heavy overfueling, miss-fire or sticking exhaust valve. Did you get a chance to check the regulator?

You'll also find that on the block timing marks are generally highly suspect and fall into the "for referance purposes only". Your own attempts will probably be more accurate but a dial gauge would be worthwhile.

[DKnight]

whats to check on the regulator tho?

the things that make me think not over fueling, or missfire is because my fuel consumption is so good.

like i said tho the timing mark does line up as in image 2, when at TDC the crank pulley is where it is, from manually making sure...

if i was to run it for a while as in diagram 3, where technically its a tooth out, do i risk killing it? coz it ran bloody nice!

[G-spot]

TDC and timing mark should always corespond, regardless of head skims,different thinkness gaskets etc, what will be out is the cam timing, depending on what cam your running you should be able to calculate at what crank angle the inlet on No1 should be opening.
For example;
the Schrink 252/276/111 cam(G40 spec cam) has the inlet opening 17deg Before TDC, so once you've set the cam in the right position then you can then set the timing, and if necessary get you MAP changed to suit.

If you've skimmed the head or fitted a thinner gasket then the distance between you crank and you cam has shortened, in some cases enough to make half a tooth difference on your cam pulley, this would relate to one tooth on the Crank Pulley.  in order to set up acccurately I'd recommend finding out the specs of the cam you have, mark the specifics on the crank pulley(ie 17deg BTDC) then place your DTI clockon top of No.1 inlet tappet, find the point it starts to lift, hold it in that position, and using a vernier pulley adjust you crank to 17deg on the TDC marker.(if you've not got a vernier pulley then you may want to slip the belt around one tooth, but this is risky, as if you move to far the the inlets touch pistons.)  Once all the mechanicals are right you can then concentrate on your timing and map.
 

[DKnight]

standard cam lol

[PeteG40]

You could look at it another way...

when the bottom end is on the spot and at tdc, the cam timing is out (as opposed to when cam timing is right the bottom end is out) if that makes sense.  This is what g-spot is saying.

[DKnight]

yeah i think that is the best way to work it, as i can tell when the piston is at tdc, so the cam one is a tooth out, but runs sweet, im gunna make sure i actually do have a g40 cam in there, i know i have, but best ot check the obvious things

dare i run it as it is, a tooth out?

[supercharged spaniel]

dan when your setting the timing 'off' so it runs better is it starting up without the problem we have??