Technical Tipo camshaft timing marks

[stepcaw]

Hi, everyone first time posting for me.

I've got a 1989 1.4L Tipo there are three white dots of paint on the cambelt pinion. The second dot (looking at the pinion face on counting clockwise) is accompanied by a groove cut into the pinion. There is about 14 degrees between the first and second. The cambelt inner cover has both the plastic moulded pip (as in Haynes) and a white dot. It's possible to align the first white dot on the pinion with the moulded pip and the notched pinion white dot of the second with the the dot on inner cover if the sliding cover is left down. Then if I lift the sliding timing piece the notch on the pinion coincides with the pip. I'm seeking confirmation from someone that the notch in the pinion has to align with the pip on the lifted inner cover when the crankshaft is at the 10 deg btdc.

Haynes doesn't specifically tell you to lift the sliding timing mark just a photo.

Purple Haynes all through my brain, lately things don't seem the same.

The third white dot is way back about 70 degrees from the first. I've got to assume this is a red herring or the whole car is a red herring suffering from white dotitis.

The original cambelt snapped (one valve replaced) so unsure of the original configuration. I've actualy tried both positions then I checked the valve clearences they seem OK so hopefully no valves are bent.

Should the camshaft swim in oil?

Haynes shows a a single white dot on the pinion, why can't mine?

At present the pinions set so the notch coincides with the pip on the lifted inner cover slider. There's maybe 1 or 2 degrees difference between the marks on the flywheel lining up and the notch with the pip for the camshaft. The best I could do - does it matter? The distributor rotor arm was aligned with no 1 lead. On cranking the beast wouldn't fire. I've tried with some help today we got a brief fire by cranking while he turned the distributor.

Things I noticed while doing the job was the linkage from the wax temperature
regulator in the air filter had come off - now re-fixed. Someones put a 1.6L carburettor on at some stage (according to the Haynes codes) using the inlet manifold for the advance retard vacuum and there's no drilling for the petrol return to tank - pipe's been bunged.

 

[(CZ)enda]

I guess you saw this:
https://www.fiatforum.com/tipo/1225...hange-camshaft-crankshaft-flywheel-marks.html

I used the camshaft/crankshaft alignment procedure described in Haynes Book of Lies and then checked the correct position of crankshaft vs. camshaft using white marks printed on the new cambelt.
It seems the white dots and stamped dot marks are supernatural phenomenon not fully understood by humans yet .

 

[stepcaw]

No to be truthful the Haynes doesn't lie I just rushed in somehow getting ignition timing mixed up with valve timing. Now I've set the valve timing according to Haynes eventhough it's in the car there's enough gap to see (once the crankshaft pulley is removed) the mark for valve timing which is at TDC. Now my valve timing is at TDC and ignition timing at 10 deg BTDC, but it's still not firing.

If I've damaged a valve putting the camshaft carrier back on it would show as a excessive valve clearence wouldn't it? I checked all the clearences and they seem fine.

 

[stepcaw]

It turned out the timing mark on the camshaft pulley was 180 deg out. I took the valve cover off and no 4 cylinder valves were closed instead of no 1 cylinder . Don't know why Fiat did this maybe because mine was one of the first there was some confusion on procedure. For now I've just swapped 1&4 and 2&3 leads at the distributor and it's running. Later I'll remove the distributor and move the arm 180.

It pays to check the positions of the lobes and not just take the manual as law although this has to have been a Fiat errore giudizio.

Haynes should have put some text stating the cambelt cover timing piece needs to be lifted not just a photo.

 

[(CZ)enda]

This seems a bit too weird to me. Are you sure nobody played with the engine before you?
These things happen - when I bought my Tipo, it was idling erratically even after I renewed all spark plugs. As I did not have the cables marked, I reconnected them according to marking stamped on the distributor cap and... the engine refused to start.
Only then I found that some idiot mounted wrong distributor cap, one with the proper firing sequence acquired when the arm rotates clockwise. To get the proper firing order, I had to buy a new one, because the arm rotates anticlockwise.
I guess the wrong cap came from some other model of Tipo/Tempra - it was factory-original Fiat-Magneti Marelli part, fitting the flange perfectly.

 

[stepcaw]

The rotor arm on my distributor rotates clockwise. There was nothing wrong with the distributor it looked just as it should in the Haynes manual. So I set the arm to No 1 cylinder at 10 deg btdc. When the camshaft pulley mark was aligned with the pip on the cover that should have been all valves (at TDC) closed on No 1 (combustion cycle) but it was No 4 lobes that looked like the valve was closed. So I turned it a bit more then No 2, according to the 1342 firing order. So I deduced that was the problem.

There are lots of questions like what the third white mark represents I'm only glad I never set the timing to that it would surely have bent a valve being 70 deg later.

Also I found out the pipe from the advance retard diaphragm to the inlet manifold was a solid stud it was getting any vacuum suction. The same stud feeds the fast idle. I've found another place on inlet manifold for the advance retard. I'll look at what I can do for the fast idle. I don't know much about car carburretors. I've had the car a year but I've never really had chance to check these things out.