Technical Fiat UNO uneven idling

[jstray]

Hello,

I've changed head gasket of my fiat uno 1372 SX (Jetronic Injection
System) and since the moment I've changed it, car uneven idles, the
range is 1800-2000 rpm, with costant oscillation cycles of 3 seconds
(that is: car work at 1800 rpm then rpm grow and become 2000, then go
down to 1800...etc)

Someone can tell me what I can do?

Tnx a lot

 

[Luke]

Hello,

I've changed head gasket of my fiat uno 1372 SX (Jetronic Injection
System) and since the moment I've changed it, car uneven idles, the
range is 1800-2000 rpm, with costant oscillation cycles of 3 seconds
(that is: car work at 1800 rpm then rpm grow and become 2000, then go
down to 1800...etc)

Someone can tell me what I can do?

Tnx a lot

Sounds to me liek your engine timing is way out What you will need to do is make sure the cam and engine are correctly aligned with each other, and the distributor is advanced to the correct degree.. Have you got a timing gun?

 

[Chas Uno]

It's also possible that there is an air leak on the induction side. You would have had to remove loads of vacuum pipes and stuff to change the head gasket, so go over all the parts you removed and make sure all is connected and tightened properly.

And it might be a daft question, but you did use new gaskets on everything else when you changed the cylinder head gasket? It's surprising the number of people who don't. If you removed the intake manifold, make sure that is tightened correctly with new gaskets. An air leak here, or also in the throttle body to manifold join can cause uneven idling.

Hope this helps!

 

[sumplug]

as others have said,also if memory is right,they have a stepper motor on these.this could be out of step.personally i think you have an induction leak somewhere.