Technical Help identifying starting issue

[pepita]

Hello forum friends,

It's summer starting season, and my usually reliable Fiat 126 is giving me starting problems after sitting idle for 6 months (which it does every year, usually with no issue!).
I only had a few hours and a single pair of hands the other day but couldn't get to the bottom of it before having to give up until next weekend where I am hoping to return with my glamorous assistant (girlfriend). I was hoping more experienced members could help me narrow down what to try.
Here are some facts, first of all:

1. It's nearly definitely not a battery issue. The first fix I attempted was to top up the battery and even to start with a jump start device. No difference to the outcome.
2. There is sufficient fuel in the vehicle and I can smell it being delivered to the engine.
3. The only change I made while it was sitting there was to fix the fiddly plastic cable clamp the pins the starter cable to its anchor point at the heating tube with the cast metal version from Axel Gerstl which I would recommend to everyone (the plastic one has broken on me at least twice). It is possible that doing so slightly changed the amount of tension in the cable, however it is does not look particularly loose and it is already on the last pin on the starter side. Adding more tension here would be one easy thing to eliminate but I am not sure how to add more tension without having to drill another hole in the heating tube to move the anchor point slightly. I also have not been able to get a good angle to try to press the trigger manually from the back of the vehicle. This has been my primary suspect because the vehicle was starting perfectly when I parked it last autumn, with no issues with the distributor or anything. But research suggests that the only role the cable/lever plays is in firing the starter motor, which is firing. So perhaps I should eliminate this as well?
4. Pulling the lever with and without the ignition turned on produces the same sound / result. The starter motor is clearly firing, and cranking the engine, but the engine is not igniting.

I have filmed a video of one of the attempts (with ignition on!) to illustrate what is going on.

Any help or suggested steps to speed up diagnosis would be greatly appreciated.

 

[bugsymike]

I would start with seeing if you have a HT spark.
Take the distributor cap off and take the centre HT lead out of distrIbutor cap, hold it so the end is half a Cm away from engine metal and get your glamorous assistant to turn the ignition as though trying to start the engine.
If you get a nice fat blue spark then look elsewhere like fuel, however if spark is poor/yellow or none existent then have a look at the contact points, when you turn the engine by hand with ignition off to the cam lobe makes the widest point gap (ideally 12/15 thousand of inch or you metric version) that is good, if gap has closed you get a poor spark.
Next have a good look at the contact area where the two points touch each other, the surface should be a nice light grey with no pitting.
If pitted and "blue" then replace the contact points and condensor, making sure points gaped correctly.
What I have found with contact points is people leave ignition on whilst testing something else or listening to the radio and it burns the points out also overheating the condensor so that it fails.
Note when checking points use a very clean tool do not get any dirt or grease in between the points or car will not start.

 

[gt alex]

Sounds strange but a thick earth cable from starter motor bolt to the frame and new earth cable on the battery.

 

[bugsymike]

Sounds strange but a thick earth cable from starter motor bolt to the frame and new earth cable on the battery.

They always help, but to me the starter is spinning the engine over fast enough, just not firing.

 

[gt alex]

They always help, but to me the starter is spinning the engine over fast enough, just not firing.

It helps the earth on the dizzy as well. I have found it helped me in the past. I had a 56 vw beetle that would never start for my wife but always started for me. Turned out I always started with my foot on the clutch providing a extra bit of earth unlike my wife who always started in neutral resulting in only starting when warm.

 

[bugsymike]

It helps the earth on the dizzy as well. I have found it helped me in the past. I had a 56 vw beetle that would never start for my wife but always started for me. Turned out I always started with my foot on the clutch providing a extra bit of earth unlike my wife who always started in neutral resulting in only starting when warm.

Ha, ha, that's another bone of contention I have had an old ex lorry driver customer engines seized due to that action, damaging crank shaft thrust bearings in the past and I get annoyed by VW etc. making depressing the clutch pedal a starting requirement, putting pressure on a shell bearing without lubrication.
Also many years ago we had a customers Mk1 Ford Cortina that the choke cable got red hot due to engine earthing failure.

 

[pepita]

I would start with seeing if you have a HT spark.
Take the distributor cap off and take the centre HT lead out of distrIbutor cap, hold it so the end is half a Cm away from engine metal and get your glamorous assistant to turn the ignition as though trying to start the engine.
If you get a nice fat blue spark then look elsewhere like fuel, however if spark is poor/yellow or none existent then have a look at the contact points, when you turn the engine by hand with ignition off to the cam lobe makes the widest point gap (ideally 12/15 thousand of inch or you metric version) that is good, if gap has closed you get a poor spark.
Next have a good look at the contact area where the two points touch each other, the surface should be a nice light grey with no pitting.
If pitted and "blue" then replace the contact points and condensor, making sure points gaped correctly.
What I have found with contact points is people leave ignition on whilst testing something else or listening to the radio and it burns the points out also overheating the condensor so that it fails.
Note when checking points use a very clean tool do not get any dirt or grease in between the points or car will not start.

Thanks for this thoughtful response. I am back on site today and will go through all the steps methodically this evening. My glamorous assistant's time will not be wasted! I will report back on progress.

 

[Greasytrucker]

Also many years ago we had a customers Mk1 Ford Cortina that the choke cable got red hot due to engine earthing failure.

I had just the same on my classic Mini years ago, my own fault though. I replaced the engine stabiliser bushes (constant job if you know Classic Mini’s) and forgot to put the earth strap that uses one of the bolts for the stabiliser back on, so it earthed through the next easiest point

 

[bugsymike]

I had just the same on my classic Mini years ago, my own fault though. I replaced the engine stabiliser bushes (constant job if you know Classic Mini’s) and forgot to put the earth strap that uses one of the bolts for the stabiliser back on, so it earthed through the next easiest point

Done a few of those in the past, including where they split away and needed welding. Usually combined with exhaust front pipe cracking at bell mouth.
The favourite trick then was forgetting to refit the throttle return spring, sniff the throttle and hear engine scream.

 

[pepita]

Hello team! Some news from the front:

First off, this test:

Take the distributor cap off and take the centre HT lead out of distrIbutor cap, hold it so the end is half a Cm away from engine metal and get your glamorous assistant to turn the ignition as though trying to start the engine.

Result: No spark!

Then, I removed the distributor cap, and the rotor arm, put the car in 4th gear and pushed it forward to turn the engine. Here is a video of the distributor while it is turning:

Now it is my first time going this in depth in to ignition (and I am enjoying it thanks to your help), but it looks like to me that there is no opening or closing of the contact points at all?

 

[Mike1alike]

but it looks like to me that there is no opening or closing of the contact points at all?

Correct! There is absolutely no movement. Something's missing, alright...

 

[bugsymike]

Hello team! Some news from the front:

First off, this test:

Result: No spark!

Then, I removed the distributor cap, and the rotor arm, put the car in 4th gear and pushed it forward to turn the engine. Here is a video of the distributor while it is turning:
View attachment 486646

Now it is my first time going this in depth in to ignition (and I am enjoying it thanks to your help), but it looks like to me that there is no opening or closing of the contact points at all?

I can see straightaway what the issue is , you have a massive gap as the spring part of the contact points is broken.
Not bad for a 73 year old with glasses.

 

[bugsymike]

Correct! There is absolutely no movement. Something's missing, alright...

Come on Mike I know you are good with electronics, but haven't you seen contact points.

 

[pepita]

That's nuts! It must have broken while it was sitting still or the first time I tried to start it...
That explains the lack of spark as well right? A consistent fault is the best kind of fault.

 

[bugsymike]

That's nuts! It must have broken while it was sitting still or the first time I tried to start it...
That explains the lack of spark as well right? A consistent fault is the best kind of fault.

I would also replace the condensor at the same time as the points as I think the contact area of points looks poor, a little high melting point grease on the fibre heel of the moving part of points and a little on the cam lobes as they look dry to me., then a small drop of engine oil on the felt in middle where rotor sits on and just to be generous a couple of squirts of the oil can on the bob weights below.

 

[pepita]

All right! Thank you. I will do as instructed and report back.

A thought has occurred: The second-best time to become intimately acquainted with your ignition system is when it has left you stranded. The best time is when it’s working perfectly, so that later, when it isn’t, you know what ‘perfectly’ was supposed to look like.

 

[Mike1alike]

Come on Mike I know you are good with electronics, but haven't you seen contact points.

I did. But I didn't touch a distributor in years. I wanted to say that it looks like one side is missing...

 

[pepita]

All right! Thank you. I will do as instructed and report back.

A thought has occurred: The second-best time to become intimately acquainted with your ignition system is when it has left you stranded. The best time is when it’s working perfectly, so that later, when it isn’t, you know what ‘perfectly’ was supposed to look like.

This is a very helpful reference video, for any future forum reader with a similar issue:

 

[bugsymike]

This is a very helpful reference video, for any future forum reader with a similar issue:

As a 16 year old apprentice back in 1969 I was fitting contact points etc. Just get the parts and we will talk you through it if you want.

 

[Mike1alike]

As a 16 year old apprentice back in 1969 I was fitting contact points etc.

I did that too. Had them on the old Dacia1310. I remember distance was 0.4 mm there, or as some would say "as thin as cigarette paper".