General Ça Marche! - well - almost

[Auguste]

Ok- first off, thanks to all of you for the advice and encouragement! Great group, I must say.
I am very pleased to say that my Panda started up today after replacing the head gasket. However, I do have yet another problem.
It is smoking much more than it was before the head gasket "blew" and idle is rough. It starts every time and life is good, then after a few minutes, it engine RPM starts to vary. The only thing I have not hooked up is the vacuum hose from the manifold to the break drum, I simply taped over it until I can get a new hose.
It is one of the models with fuel injection and has the ECU and as Porter says, "no further adjustments can be made" for timing.
Any ideas on what might cause the thing to smoke and run roughly?
Thanks,
Auguste

 

[voorhas]

Some ppl say that after having the battery disconnected for a period, your ECU loses all the acquired data regarding the variable running parameters (the ones its suppose to "learn" while you drive and allow it to make small ajustments) and that can cause the car to run roughly for a while. It usually goes away after a couple of days of normal running at the most.

The smoke issue is puzzling me, though. Whats the colour? Is it using any water or oil? Was there any kind of liquid sealant you might have used that could have leaked into the engine? Another thing, did you have the head checked for distortion?

Goncalo D.

 

[Enzo]

I'd have asked you this in the previous thread, but now I'm here:did you replace ALL the oil seals around the valves' stems??When you dismantle the head and unthread the valves they get irreparable damaged, so...new ones neededB)!If this is the cause you should notice light-blue smoke, because of oil burning[xx(].

Passion has neither brands nor models!

La passione non ha nè marche nè modelli!

 

[Auguste]

Enzo - no, I didn't touch the valves, they didn't appear to need any work. I did replace all the other gaskets which came with the head gasket, including the cam shaft seals.
Goncalo - I understand the fact that it might need to relearn. The smoke looks gray, not too dark. There is some water on the pavement at exhaust, but it doesn't appear to be using water nor oil. I haven't run it a lot but think I will let it idle for a long time tomorrow to see what happens.
I was too nervous today to take it for a ride but might get the nerve soon.
Auguste

 

[Auguste]

I forgot to mention that I did have the head resurfaced or "milled" as they say in America.

 

[John H]

Smoke and rough running - once any stray oil residues from the rebuild are burnt off - sounds like rich mixture.

I'd agree with voorhas that the ECU needs to relearn its settings.

This topic reared its head a few months ago, and Enzo provided a link to an Italian site.

This is the English translation provided by Pete in this thread

https://www.fiatforum.com/forum/topic.asp?TOPIC_ID=4795

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Hello Enzo.
I have translated the passage you refer to as best I can. Would you please read and tell me if I have missed anything or lost any of the meaning?
Thanks.

1, Disconnect ECU or battery for some minutes.
2, Restore connection.
3, Start engine and without touching accelerator, allow to run until cooling fan cuts in.
4, Test drive, attempting to simulate all normal driving conditions.
5, This should re-program the ECU, adjusting the carburation to suit the age and wear of the engine.
6, This proceedure serves to stabilize the settings and to minimize the time required to return to normal tick over speed on the release of the accelerator.

Had to laugh, Alta-Vista "Babelfish" translates ECU as "Telephone Exchange"

Thanks again, Pete.

================


That method ( ISTR that the engine should be hot, and the fan just cut out at the start of that procedure, but can't find it in print this morning..) works for my Panda, but it has a different ECU to yours...


Regards


John H

 

[Auguste]

John - thanks - I'm up to step 4 but got cold feet.
My atelier is on a pretty good hill and I still have to replace the vacuum hose to the breaks so I will wait until I get a new one.
But, running it until it the fan kicked did help - I could hear that little box by the battery clicking away as the engine seemed to change RPM etc. Still seems a little rough but exhaust is now a whitish smoke, and not so heavy.
Step by step ...
Auguste

 

[John H]

If the "white smoke" is steam, you're in OK.

Agreed about the brakes