Technical 1991 Fiat Uno Fire 1.0

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Technical 1991 Fiat Uno Fire 1.0

autokaci

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I have just replaced the cylinder head gasket and today put on a new timing belt (104 teeth same as old one) but after lining up the crankshaft and camshaft sprockets as explained in the Haynes manual (arrow A in attached pic), I found that mark on timing belt camshaft end is one tooth away and for this mark to line up with the one on sprocket and to line up the belt and sprocket marks I had to turn camshaft one tooth and like that it lines up with the deep vee on cylinder head (arrow B).

Can anyone clarify this and what I might be doing wrong please?

Kaci
 

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Dont necessarily trust Haynes. They showed the marks 180 degrees out when I needed their guidance on a Renault 12 . I wasted 2 days before realising. Check the valves are opening and closing as you would expect using the 4 stroke cycle. Line up rotor arm with No 1 plug lead or check when it sparks on No 1 plug . Get TDC and start from there. Only turn engine by hand.

No1 TDC Exhaust closing Inlet opens as
Piston descends then inlet closes both closed as piston comes uo
Piston descends and exhause opns
Piston rises and ehaust clsoed and inlet opens

If the valves are sequenced wrong then the marks may be wrongly aligned. Its what happened to me. Or ring your local dealer and ask the workshop foreman when the marks are correclty aligned. I find them usually helpful.

The notch may be for a locking tool?
 
Thanks Panda Nut. I never had issues with Haynes manuals yet and I've used them a lot on various vehicles, but nonetheless will take your suggestion.

I very much doubt the notch is for a locking tool
 
First of all I've never used the white lines on the cam belts for any timing purposes.

For the Uno and other Fiats to get the crankshaft exactly to TDC then use the timing marks on the top of the bell housing. There is a rectangular rubber bung and when removed you have a nice wide window and timing marks to align to. The marks (if any) on the cam belt end of the crank are not accurate enough due to the small diameter compared to the flywheel diameter.

You may find this corrects the the one tooth error you are seeing.
 
First of all I've never used the white lines on the cam belts for any timing purposes.

For the Uno and other Fiats to get the crankshaft exactly to TDC then use the timing marks on the top of the bell housing. There is a rectangular rubber bung and when removed you have a nice wide window and timing marks to align to. The marks (if any) on the cam belt end of the crank are not accurate enough due to the small diameter compared to the flywheel diameter.

You may find this corrects the the one tooth error you are seeing.
Thank you for that. I completely forgot about the flywheel marks 🤦‍♂️
Will do it from there and see if the one tooth error is corrected
 
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