The reason I ask is to rule out whether or not the mechanic has tried to do it by eye and ****ed things up without knowing it. Would never try it myself... Well... Maybe

Yes to do it properly there are 3 tools required

1) camshaft sprocket spanner to hold the sprocket steady while the securing nut is released. This tool can be worked around / alternative easily made.

2) inlet camshaft locking block

3) exhaust camshaft locking block

2) and 3) have to be purchased, come as a paired kit.

If the either of the camshafts have been moved when the belt has been removed the 2) and 3) ARE REQUIRED. There are no other visible timing marks to put the shafts back in the correct position.

So if the mechanic was attempting to cheat and accidentally moved either of the shafts from their TDC rest position (and he/she had not very carefully marked their positions both to head alignemnet AND on the old cam belt before removal, or otherwised secured the sprockets relative to each other) then the timing will be wrong.


Hint / Tip for securing camshaft sprockets from accidentally rotating. This tip will not secure them against larger forces. I would always recommend buying the proper tools but in an emergency the following tip will help. Especially effective for older engines with timing marks and not equired with variator.

1) Get an old cambelt with same tooth size and spacing
1B) Get a collection (four or more) of 1/2 inch "Bulldog" paper clips
2) Cut the belt in half, and then cut a length of belt long enough with reasonable overlap to be able to do a complete figure of 8 wrap around the camshaft sprockets
3) Cut this belt down to 1/2 width, or just less than 1/2 width
4) Slide the belt to be replaced gently forward exposing the rear half of the camshaft sprocket
5) Using the cut belt make a figure of 8 wrap around the rear half of the spockets and periodically secure to sprockets with the bulldog clips
6) You can now remove the old belt fully and replace.

Damn I love this forum. Everything I needed to know. Thanks guys

s130 said:

I totally agree with you. I mention the alternative based on many years of Fiat engine timing experience.

Go back to Strada Abarth era and Fiat would have you remove the cylinder head, use a depth guage with engine set to 90 degrees off TDC (requires a special tool) etc. Theoretically setting TDC at 90 degrees off TDC is as accurate as you will ever get. If you can't see/understand this then you have no business in timing any engine regardless of the tools provided.

Often the formal instructions/guides are well and truly excessive in their requirements. They set the base, unambiguous and definitive 100% perfect timing criteria etc. In reality, depending on "circumstances", then alternative simpler methods are perfectly valid and just as accurate.

If you know the baseline (history) and know what you are doing then you can bypass/take short cuts over the "100% perfect" guidelines. Sadly many garages/even main dealers take these shortcuts and totally screw the timing of the car. 9 times out of 10 they get away with it, save themselves loads of money and time, bill you for the "full" job cost with no short cuts and possibly add cam cover gasket cost (NOT cheap) onto the bill, which they never replaced anyway.

Click to expand...

You are right in what you are saying, I really don't like people mentioning the other method as it will usually result in them thinking, "yeah I can do that".

It is very important that owners choose a competent Italian car specialist, in fact I have just had an Idea!

Got a chance to plug it in again today and got three error codes:

p0135; Heated oxygen sensor (HO2S) 2, bank 1 - circuit malfunction; Fuse, wiring, HO2S, ECM.

p0141; Heated oxygen sensor (HO2S) 2, bank 1 - heater control - circuit malfunction; Wiring, HO2S, ECM

p0155; Heated oxygen sensor (HO2S) 1, bank 2 - heater control - circuit malfunction; Wiring, HO2S, ECM


all seem to relate to a lambda sensor. Now, my question is this. My B has had an engine swap with a Punto HGT - mechanically, very similar. Do I buy the HGT Lambda, or the Barchetta Lambda? The have different part numbers. (it's the rear sensor I need, I think, not the two pre cat). Or could these errors simply be logged from me running the car without the Lambdas plugged in?

Not easy to answer. The different part numbers could just be a simple supercede of part numbers, a connector difference or different lengths of cables.

Got try www.ignitionparts.co.uk

They do Lambda sensors (plus other stuff) for the 'B' on both engine series 188A6 and 183A1.

I note that for both versions they say "Notes: You will need to cut of the plug of your old sensor and attach it to this sensor the connectors are supplied"

They charge £49 for a Llamda sensor.


Having bought other really plug compatible sensors from them in the past this "use your old connector" note suggests to me that Fiat have done/use a non standard OEM part on the 'B'.

For the Punto HGT they list the sensors depending on engine series.

If you're running a Barchetta ECU, use Barchetta sensors.

I'd advise against using universal Lambda sensors unless you can guarantee a waterproof joint where you join the old plug onto the new sensor leads. The signal back from the sensor is very small and can easily be disturbed by moisture.

There are only really two different types of lambda sensor, Zirconia and Titanium based. There are however two, three and four wire variants so it's important you get the right type. More info here:

http://www.lambdasensor.com/main/mtypes.htm

I've now replaced all the lambda sensors and it's made no difference. What can I try now?