can't figure out what's wrong exhausted all possibilities :(

[jake3340]

My bis keeps missfiring and loosing power when driving sometimes it doesn't start and sometimes it barely moves. I can hear the exhaust sort of sneezing and missfiring when I drive.  The points and  condenser are new and set right start plugs and he leads are new as well and  car is working fine.  I don't know what else is wrong what could be the problem ?

[Hazey-n-Marc]

Have you checked the fuel system? Pipes, unions, filter and pump. Also check vacuum hoses, linkages and units. There is also a small wire in the top of the dizzy that can snap, you will need to wiggle it to check.
Also check the earth straps and that your choke butterflies are moving correctly and not flapping. Cleaning the carb might help as well.
Hope you find the problem.

Marc

[jake3340]

Fuel is working fine and all the vacuum pipes are connected what earth straps am i looking for ? Where are these located and what is a dizzy ?

[andyzeetec]

Earth strap (Copper braided 1" wide) connects chassis/body to engine. It's just above the exhaust.

Dizzy is the distributor.

[jake3340]

Il check the earth strap the wire coming out of the distributor is the one going in the condenser right ? Thats a new wire just changed the condenser.

[Hazey-n-Marc]

No, it is inside the dizzy, just pop the top off and you will see it. I think it went to the other end of the  condenser screw.
The vacuum pipes need a thorough check for cracks, also pop them off at the end opposite the vac unit, with the dizzy lid off, and check that the advance is moving correctly by sucking on the hose. Caioflyer, I think it was, spent months and a lot of money replacing all sorts only to find a 30p section of vac hose had a pinprick hole in it.
It could also be leaky carb gaskets, get some carb cleaner and squirt it around the base of the carb, start the car and look for bubbles.
The inlet manifold gasket can also cause lean running and is easy to change, just a bit fiddly getting to a couple of carb bolts.

Marc

[jake3340]

Its something in the electrics the car refuses to start now, the points where set right and the condesner is new, i noticed the wires coming out of the points are melted and damaged might be the problem or the car is not times right, my mechanic had changed the distributor and told me it was bent, I cant figure out in my mind how a distributor can bend without it being pulled off and trown against a wall or something but could it be this new distributor her put in bent again ? Also do you know where I can an electronic kit for my distributor for the fiat 126 bis watercooled.

[Hazey-n-Marc]

Did the mechanic get it running?
I've never encountered a bent dizzy, cracked but not bent. Is he a trustworthy mechanic?
What is happening when you try to start it?
There isn't an electric ignition kit for the BIS, but some members have adapted the kit from an aircooled.

Marc

[jake3340]

Yea he got it running perfect, but after 4 days the car just stopped working first it slightly began to cut out whilst driving and after a day driving it around it got worse and now does not want to start, Its been over a week since i went near the car and tomorrow I am thinking I go give it another try to get it working. What could have possibly gone ? The vacuum pipes are new pipes I had fitted them on a month ago. The condenser is new and the points are new but have the wires slightly damaged, I will buy a new set and see if its from them tomorrow. Could the coils be bad ? I am thinking of buying a new set too. What coils do I need for the bis watercooled ?

[Hazey-n-Marc]

Are you certain it is getting fuel to the carb?

[jake3340]

Yup I took out the pipe going in the carb cranked the engine and fuel came trough, also when I remove the air filter cover over the carb and push the gas cable going in the carb it shows a vapor of petrol in the carb.

[Hazey-n-Marc]

Check for a spark, in the dark preferably. If you have a decent blue spark then it is either timing or the carb is blocked or broken.
Vacuum problems shouldn't stop it from starting. I doubt that the air box is completely blocked, but give it a quick check.

Could it have water in the carb?

[andyzeetec]

Dodgy connection somewhere maybe?
As Marc said check for a blue spark, you say you have new ht leads, plugs. Might be worth checking the coil resistance, primary and secondary sides with a dvm. I cannot remember the values but they are in the subscribers section or do a search.


http://www.ebay.co.uk/itm/NGK-IGNITION-COIL-FOR-FIAT-126-0-7-1981-1992-U3013-/330992106115?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item4d10aaba83

[jake3340]

Il have a look at the ignition coil and check the spark tomorrow the spark plugs are new too doubt they would be bad, if they look good il have a look at the carb the problem is my manual does not explain how to rebuild my carb, i always wanted to buy a carb kit for my twin weber but I have no idea how to dismantle it rebuild it and stick it back on my bis. 

[Hazey-n-Marc]

http://www.pouleto.ch/fiat500/?p=332
Found this page that takes you through rebuilding the dgf 30. Unfortunately I don't speak French.