Sounds like engine exploding!

[tdneVmo]

Skoda favorit 1,3.

I started it, and then after 100 meters, it sounded like two firecrackers exploded under the hood.

When it is making the bang, it hesitates for 1/4 second. What the?

Nothing to see under the bonnet.

[TeflonTom]

misfire?

[KenONeill]

It sounds like the car's actually backfired.

Carburettor or fuel injection?

[AhmetH]

its probably caused by rotor in the distributor.(or distributor itself)

i use LPG converted 1.3 felicia with carburator fueling and its very sensitive when it comes to ignition system thus i experienced so many situations.

this summer when i press accelerator it began misfiring under load and a little firecrack sound probably from center exhaust side.

from the experiences i thougt it was from spark plugs but after a good diagnose i found that the reason was rotor arm.

[tdneVmo]

Ok. So a whole new destributor?

[tdneVmo]

Injection.

[KenONeill]

On the point in #5, you should be able to replace the rotor arm without needing to replace the rest of the distributor.

On #6, I can rule out several causes of misfires now, and would say it's probably ignition-related.

[tdneVmo]

Ken. When it says bang, it stalls for about 1/4 second.

I will try destributor rotor arm.

I can't think of anything else, that can create a misfire just like that?

[Phil-E]

It could be a combination of things.

Other things that could be causing such problems are the spark plugs, HT leads, coil pack, crank shaft sensor etc.

It could also be that the timing is off slightly and maybe the distributor needs lining back up. Wouldn't hurt to do this anyway.

Also when was the last time the valve clearances were checked?

Phil

[tdneVmo]

Plugs also? I will check the plugs coil is new. Crack shaft sensor=top dead center sensor?

Hmm i dont know. It has just went over its date of periodical service, so i dont think thats the problem?

Would that actually cause a bang?

[djaychela]

Does the dizzy do the timing on the SPi engine, or just distribute the spark? Haven't got a manual handy...

[KenONeill]

Does the dizzy do the timing on the SPi engine, or just distribute the spark? Haven't got a manual handy...

Distributing the sparks is the ignition timing!

[AhmetH]

im assuming the favorit in this topic is not fuel injected when i wrote about dizzy

here in Turkey you cant find one single favorit with fuel injection all of them are carburated (jikov lekr 28-30)

Edited 11 November, 2009 by AhmetH

[Phil-E]

The spark is controled by the ECU etc but the actual dizzy just distributes the spark. The ecu has no control over which spark plug gets a spark and when.

The dizzy itself can be adjusted/fine tuned by setting the engine to TDC then re-seating it and lining the arm up with the first electrode (there is a little dimple on the top of the housing of the distributor itself that show where no.1 spark whould be set).

I did this with mine after changing the timing chain to cure a bad misfire that was occuring.

I would make sure all other components are in good working order before bothering with this though.

im assuming the favorit in this topic is not fuel injected when i wrote about dizzy

here in Turkey you cant find one single favorit with fuel injection all of them are carburated (jikov lekr 28-30)

No you were correct in saying that. The fuel injected engines in Felly's and Favorits still have a distributor! It is only the MPi (the later engine) that doesn't have one and this is done with a coil pack entirely controlled by the ECU.

Phil

[AhmetH]

thank you Phil recognize it now

so i still recommend the same for problem

[djaychela]

Distributing the sparks is the ignition timing!

No it isn't.

Most ECU-equipped engines with distributors (as opposed to wasted spark with coilpacks directly feeding the spark plugs) get their timing reference from a crank sensor. The distributor timing doesn't have to be anywhere near as accurate as on a points setup or an electronic one where the timing reference is taken from the dizzy. The distributor is merely distributing the spark to the appropriate spark plug, it's not got anything to do with the timing, so it can be 20 degrees out and the car will still run fine.

[tdneVmo]

Wow

My friend is trying to fix it, i hope it turns out nice.

[TeflonTom]

No it isn't.

Most ECU-equipped engines with distributors (as opposed to wasted spark with coilpacks directly feeding the spark plugs) get their timing reference from a crank sensor. The distributor timing doesn't have to be anywhere near as accurate as on a points setup or an electronic one where the timing reference is taken from the dizzy. The distributor is merely distributing the spark to the appropriate spark plug, it's not got anything to do with the timing, so it can be 20 degrees out and the car will still run fine.

all true ken, although in it's basic terms, all the distributor does is er.. distribute the ht to the correct cylinder. having said that quite a lot of engines have a hall effect switch in them so the position of the distributor needs to be within a certain range. i think 20 degrees is a bit much, but maybe +/-10 would be about right. to set the basic ignition advance angle on these you need to but it into basic settings, but you need a login code which i cannot for the life of me remember at the moment, this locks the ignition advance so you can set the base timing using a timing light

hall effect switch, 1.6 aee engine (at TDC, you can deduce from this that the timing reference is 60degree BDTC), turning the distributor body alters the relative alignment between the trigger wheel and the sensor

[Phil-E]

The 1.3's don't have a hall sensor in them though. My old skoda dealer tried to con me into buying a new dizzy as they said the sensor had failed in it. Took a while to convince them that there wasn't even a sensor in there!

It is still pretty important to get the dizzy lined up properly and certainly won't harm checking it is all tightly fixed in place and lined up.

Wish the dizzy could be removed and replaced with a system like on the MPi engine though. Is a pain cleaning all the dust out the cap and oiling it etc.

[djaychela]

The 1.3's don't have a hall sensor in them though. My old skoda dealer tried to con me into buying a new dizzy as they said the sensor had failed in it. Took a while to convince them that there wasn't even a sensor in there!

My point precisely.