Not much luck this week - point gap problems

[AlleyNiki]

Hi all,

This must be black November for my car.. 3 different problems  !

I had to call the RAA out today because my car (1989 aircooled) started to misfire badly. The misfires were few and far between, but then over a 7 km drive to work, it got noticeably very bad (undriveable).

After cleaning up the points and re adjusting them (he didn't know the Fiat specs but told me he'd given it the normal gap clearance most cars have) the car worked brilliantly... for the 7km drive home.

Then it started to play up again and now it's just as bad.. 

Here's what I know:

I have sparks (the engine still starts after all).
I fit new spark plugs, leads and a condensor capacitor a few weeks back. (when the engine started to misfire on acceleration a few weeks back)
I've tried two different rotor arms - same problem
It's clean inside the distributor.
The carby is clean with no problems.

Does anyone think that I should replace the point assembly? Also, does anyone think it's timing gear related? 

Hope you guys can help! Thanks in advance 

Alleyniki

[gsxr126]

Have you tried looking at the fuel side of things - filter, pump, lines. Check for air bubbles in the line.

[AlleyNiki]

I did a fuel pump check a few weeks back when I had similar issues but the pump is working fine. I disconnected the hose and cranked the engine and a healthy spurt of fuel came out..

Also, the carby had fuel in it, and no jets were blocked. It was nice and clean inside...


One thing of note is that I was checking the cables around the base of the distributor, on that post where the coil cable and capacitor cable are screwed on, and after shifting one of the cables the engine completely died.. It's too dark now, but I might do some more experimentation with it. 

The coil is fine - I'm getting about 3.9 ohms on the primary and 8000 ish on the secondary windings.

Oh well, maybe I should check the bolts on the points to see if there's something loose there...

 

[AlleyNiki]

 
It's not the points. It's the brand new condensor I installed about 4 weeks back.. It's gone open circuit... or short circuit... well broken.

I found this out when I tried bridging the old condensor across to see if the engine ran smoother, and it did.

So my question is now.. what would make a car start chewing through condensors? 

[Rusty's Uncle]

Those condensors have always been & will continue to be the weakest link in the ignition system on the Fiat 500 and 126 engines. I have had new ones break down very quickly then others seem to go on for ever. Best to carry a couple of spares or eliminate them by fitting some form of electronic ignition  

[dajwid]

Ditto, the condensers are useless, I have also had the same new ones faulty or last a day then die. As rusty said another will go on forever.

[eben80]

Cheap EI modules available on eBay these days. I'm running one of them.  No problems so far.

[AlleyNiki]

Those condensors have always been & will continue to be the weakest link in the ignition system on the Fiat 500 and 126 engines. I have had new ones break down very quickly then others seem to go on for ever. Best to carry a couple of spares or eliminate them by fitting some form of electronic ignition  

An electronic ignition would be great. Might have to wait around though until I have the cash handy!

I've bought a new condensor and so far, so good.

Apparently you can just use a .25 microfarad capacitor (that's all the condensor is, after all!)

[nrg19uk]

here is a small statement i came across
capacitor contains a moist separator inside and it will dry out of the unit gets too hot, causing it to develop an internal short circuit. The capacitor can fail if its temperature routinely goes above 150 degrees Fahrenheit.

The small condensor on the dizzy is in direct line of the the hot air being pumped out the cooling flap and the heat from the exhaust so it gets pretty warm.


I had a big think about this and after seeing a few pictures of polish 126 i see they have the coil on the opposite side of the engine bay so i decided to move mine there. i havent tried it yet as im still building the engine  but it makes sense to keep it away from the hot side of the engine

[Pete126]

I had a big think about this and after seeing a few pictures of polish 126 i see they have the coil on the opposite side of the engine bay so i decided to move mine there. i havent tried it yet as im still building the engine  but it makes sense to keep it away from the hot side of the engine

I'm sure someone on the forum Moved the condenser to the coil end to keep it cool 

[nrg19uk]

I had a big think about this and after seeing a few pictures of polish 126 i see they have the coil on the opposite side of the engine bay so i decided to move mine there. i havent tried it yet as im still building the engine  but it makes sense to keep it away from the hot side of the engine

I'm sure someone on the forum Moved the condenser to the coil end to keep it cool 

sorry for my poor explanation(pub lunch  ), my condensor is still fitted on the dizzy.

i have moved the coil to the left hand side of the engine bay away from the heat of the exhaust  im not sure how you would go about moving the condensor, any protection against the heat would be a bonus...

[Emin]

If I were to change the condenser I'd chose one with the same capacity as the existing one but type of mkp or mkt for which an electronic parts store might help. Mkp or mkt type of condensers do not contain any electrolytes so there's nothing to dry out. Also higher voltage rating for the same capacity means more durability. Electronics-hobbyst's point of view. Anyway they will be cheap as chips, so not an expensive experiment. If/when i get a 126 i'll give it a go if i don't switch to electronic ignition, which i may build myself.