Technical seicento sporting will not start

[fingers99]

Checked that I have between .5mm and 1.5mnm gap at the crank sensor

Well 0.5 - 1.5 is surely outside tolerances at the upper end! But if you're getting a spark...........

When it tries, is it spitting back? Did you take the crank timing pulley off at any stage? It's very easy to put it back with the pips in the wrong place. Do that and the timing will be way out, although it'll look right according to the belt and the timing marks..............

 

[keithmercer]

0.5 - 1.5mm is from the Fiat manual.

If by the crank pully you mean the larger one with the teath which carries the alternater belt then yes I have removed and refitted but it has a location pin so you can get it back in the right place.

I would not say it is spitting back but I my experience I does feel like the timing is way out (if it had a distributor I feel by now I would be moving it back and forth while cranking to see if I could get it to catch).

 

[fingers99]

I would not say it is spitting back but I my experience I does feel like the timing is way out (if it had a distributor I feel by now I would be moving it back and forth while cranking to see if I could get it to catch).

Ah, the good old days!

Suspecting fuel side. This isn't an MPI car by any chance? If so, check the connectors and wiring to the camshaft sensor (on the front of the cam cover, same end as oil filler).

One last thing to check is that the keyway on the crank pulley hasn't sheared. If it has, you'll get infinately variable timing, even if everything else lines up perfectly. They are very weak.

 

[keithmercer]

Confused!!!!!!!!!!!!

I thought I would double check that I had Number 1 on TDC on its compression stroke when the timing marks lined up and low and behold cam shaft marking was 180 deg out. So I reset the cam belt thinking I had identified the fault but it would still not start.

Just rechecked and again cam shaft 180 deg out when Number 1 is on it compression stroke.

Am I missing something?

 

[fingers99]

Engine is wasted spark so a genuine 180 degrees makes no difference. Cylinder will fire on exhaust and compression strokes.

 

[rallycinq]

Is the camshaft turning when you try to start the engine?

Cheers

D

 

[fingers99]

Is the camshaft turning when you try to start the engine?

Cheers

D

Good easy check! If not, suspect the keyways (most likely crank pulley).

 

[keithmercer]

Ok then.

When number 1 is at TDC on the compression stroke should I expect to see the missing teeth on the crank shaft pully wheel at or arround the sensor? because mine are not.

 

[fingers99]

It'll fire before TDC, so they should be past it. How are you checking TDC?

And do check that the cam pulley is moving when you try to start.

 

[keithmercer]

I am checking for TDC by looking in the spark plug hole and when number one is on TDC the mark on the driving pully is in the right place so that would suggest that the key on this pully is OK (the bolt is extremlly tight and I suspect I will need a puller to check fully).

The cam pully does rotate when the engine is cranked but I have not confirmed that the cam is.

Now here a thing; when I checked to see if the cam pully was rotating, I had to turn the key from outside the car and consequently did not press the accererator and it ran! Only for about 15 sec and rough as a bear but it ran.

Back to the timing belt. I can still not get number 1 on the compression stroke at TDC and the cam pully mark to align as it should! Its always 180 deg out. I know you say its a wasted spark system and assuming the drivng and crankshaft pullies are in the right place then it should fire at the correct time. But if the cam is 180 deg out, that could mean that the values aren't doing what they should when they should.

Any views?

 

[fingers99]

Try and ckeck your TDC with TDC from the flywheel (pull out the little rubber grommet on top of the clutch cover).

 

[keithmercer]

Yes that aligns also.

 

[fingers99]

Is it MPI or SPI?

 

[keithmercer]

Spi

 

[fingers99]

Can you hear the fuel pump priming?

 

[keithmercer]

Have checked fuel pumping into and out of the injector body (by removing the hoses and turning ignition).

Also have checked fuel out of injector when cranking.

Also have tried easy start.

 

[keithmercer]

At last I think I have found it!!!!!

The Driven pully (cam shaft) has sheared its key. Poor design really, the pully is pressed and the key is punched and folded hence inherently weak and it has just sheared.

Obviously this has resulted in the timing of the cam and valves being out to the crank and pistons. All I have to do now is find one and put it all back together.

A big thankyou to every one who has posted particularly Fingers99 and rallycinq. It's been emotional!

 

[fingers99]

It's been emotional!

Certainly has!

If you can't get one, PM me: I have one off a Punto 75 head which is doing nothing.