500 (Classic) Starting problems FIAT 500f

[kampo]

If you get really desperate Mario. Did you know there is a Fiat specialist in Kings Cross?

http://www.fiat500.cc/store/r-proietti-limited.asp

Thank you tony may give them a ring if tomorrows test don't produce anything

I m hopeful though

 

[jjacob]

Hi jjacob thanks
Based on the Haynes readings though the new Lucas coil that reads 10.6k ohms from HT turret to + or - of coil is not a goodcoil? Or am I understand this the wrong way? Same would apply to the original coil which read 7.6knohms at 20k scale?

I think you should keep the second coil that you used. The one that tested at 5.9k ohms. You can most likely return the Lucas coil you just bought.
John

 

[kampo]

Ok so take it one step at a time away from the battery.

Measure first at the battery take a note of the voltage reading between the + and - terminals on the battery. Then take a reading from the battery + to somewhere on the chassis, a decent earth point , somewhere like the fuel tank strap bolt.

Then from fuse 30 on the fuse box, there are two red wires. Measure from them to the chassis maybe the bolt holding the fuse box on.

Then the red terminal 30 on the ignition switch to earth.

Then put the red terminal 30 back on and measure on the terminal where the two blue wires are connected. Not the blue wires themselves but the actual spade connector they connect to on the switch measure to earth. (So red lead from meter to the blue wires terminal on the switch, black on the meter to earth on the chassis). You need to switch the ignition switch on to do this one.

Next measure at the coil, take the blue wire off and measure to earth from the blue wire terminal. i.e. Put your red meter lead touching the blue wire and black lead to earth. Then plug it in to the coil and take the measurement again on the coil +. Again ignition switch needs to be on.

Make sure you take an accurate note of all the results on a bit of paper and where they were taken. Then post them up.

Morning here are my readings

Battery + - terminals 12.45volt
Battery + terminal and an earthing point in my case bolt strap of fuel tank
12.45 volt
Fuse box 30 right hand side of fuse I only have one red wire not two I. Fact that's the only red wire in fuse box red wire terminal to earthing point bolt strap of fuel tank 12.43 volt
Red wire terminal 30 on ignition switch (spade of terminal) and earthing point strap bolt of fuel tank 12.43volt
Ignition on and touching the blue wire spade and the strap bolt earthing point 10.75volt
Coil blue wire disconnected 10.68 volt
Coil blue wire connected to oil 9.60volt

Going to measure Jacobs stuff now and revert

Please advise

 

[kampo]

Your ohm readings you took on the coil are fine. 5900 ohms should be good, and 3.2 ohms is also fine.

If you have around 9.5-12 volts at the coil that should be enough.
I don't think the problem is the coil.

We are down to basic diagnostics.

Do the following:
1. Disconnect the small wire on the side of the distributor. Connect an ohm meter between the terminal on the distributor and the engine block. With points open you should have an open circuit. With points closed you should read resistance no more than 1/4 ohm. If you do not have this good ground connection through the points, then you may have a bad condenser or dirty or worn point faces.

2. Check with your meter the resistance of the spark wire that goes from the coil tower to the distributor cap center terminal. You should really not see more than 12,000 ohms (12k ohms).

3. Check to make sure the surface of the points are clean and the gap when the points are on the high side of the distributor cam are set correctly.

4. Make sure the distributor rotor turns when you operate the starter motor.

5. Make sure the carbon contact on the inside of the distributor cap is there and is making contact with the rotor.

6. If all of this checks out, then you may have the distributor timing way off.

John

Jjacob for point 1 and 2 above I cannot get readings

I have the ohmmeter in 20k scale when the points are open my reading shows 1 or unmoved from when I set it to the scale. Same applies when I put it on 200 ohm scale I get reading 1.

When I close the points with the current condenser I get a momentary reading of 01.0 and the. Drops to 0 I have since replaced it with the new magnetti one and I get momentary readings and then drop to 0 I can't even read them they drop so fast

Then for the HT wire Both sides coil and dizzy I get 1. I. Both the 20k ohm scale and 200k ohm scale
Clueless

 

[jjacob]

Jjacob for point 1 and 2 above I cannot get readings

I have the ohmmeter in 20k scale when the points are open my reading shows 1 or unmoved from when I set it to the scale. Same applies when I put it on 200 ohm scale I get reading 1.

I am assuming that you are getting a reading of 1 ohm. This is your problem. The points are grounded when open so the coil is never "charging up." When the points are closed you said you get 1.0 which then drops quickly to 0. That is the condenser doing that which is what it is supposed to do. 1.0 or 0 means you have a connection to ground with little resistance. That is good.
When the points are open you should have a reading like you would get with your meter on and the two probes not touching each other or anything. This will usually show as "OL" (Open Lead) or show a really high ohm reading. You are seeing the same reading as with the points closed. This is the problem. This is why you have no spark. The coil charges while the points are open (this time is called the dwell time). There is no connection to ground during the time the points are open. When the points close the path to ground is made and the coil discharges sending a high voltage to the distributor center terminal.

I will make a separate post to tell you hopefully how to fix this.

Then for the HT wire Both sides coil and dizzy I get 1. I. Both the 20k ohm scale and 200k ohm scale
Clueless

You need to remove the HT wire from the coil and the distributor center terminal and do this resistance test. If you have plug wires that are metal wire on the inside then you should get a very low ohm reading. If the conductor inside the wire is carbon coated fiberglass, you should see something like 5000+ ohms.

John

 

[jjacob]

So now let me explain what I think is wrong and how you can check and maybe fix yourself.
The black wire from the coil to the distributor is a wire that grounds the coil windings. It is connected to the points but is insulated from any ground by plastic or rubber insulators at the distributor. When the points are open the ground wire has no path to ground. When the points close the path to ground is made.
I think the problem you have is that the black wire connection at the distributor is finding a ground when the points are open. This means the insulator is broken or worn at the side of the distributor, the wires are connected incorrectly to this terminal, the black wire from the coil to the distributor has a worn spot in the wire insulation and is grounding out, or the insulator on the shaft of the points is worn.
John

 

[Vitesse]

1 . on that meter means open circuit. So when Mario is reading 1 . on the meter with the points open it's o/c as you would expect. With the points closed it will measure a resistance to begin with whilst it settles to 0.00, a short circuit. So it looks like it is behaving correctly to me?

 

[jjacob]

1 . on that meter means open circuit. So when Mario is reading 1 . on the meter with the points open it's o/c as you would expect. With the points closed it will measure a resistance to begin with whilst it settles to 0.00, a short circuit. So it looks like it is behaving correctly to me?

I don't think that is correct. He is getting the same reading with the points open or closed. There should be two radically different readings. One with points closed showing very low or no resistance, and one reading with points open showing very high resistance.
John

 

[Vitesse]

Jjacob for point 1 and 2 above I cannot get readings

I have the ohmmeter in 20k scale when the points are open my reading shows 1 or unmoved from when I set it to the scale. Same applies when I put it on 200 ohm scale I get reading 1.

When I close the points with the current condenser I get a momentary reading of 01.0 and the. Drops to 0 I have since replaced it with the new magnetti one and I get momentary readings and then drop to 0 I can't even read them they drop so fast

Then for the HT wire Both sides coil and dizzy I get 1. I. Both the 20k ohm scale and 200k ohm scale
Clueless

I must be reading it differently then it? 1 when the points are open? 0 when closed? I asked Mario the other day what meter he had and its the one below. He told me where he bought it and as it was so cheap and I have a trade account there I bought one.

As you can see it displays a 1. When it is open circuit.

 

[gordinir8]

Picture explains a lot, that 1 reading means nothing, open circuit, multimeter is waiting for a measurement. You should buy/find/borrow a multimeter with a beeper, it will help you on open or close circuits.
Thomas

 

[fiat500]

You should buy/find/borrow a multimeter with a beeper, it will help you on open or close circuits.

I take my cue from Thomas, but at the risk of confusing things more and whilst confessing not to be the most knowledgeable electrician in the world. I find that when testing the LT circuit for the breaker contacts open/closed point it's easiest to use the continuity tester; I think it's just to the right of the 6 o'clock position on Tony's image. It will have the beep required and make things black and white (on this point of contention only!)
My two penn'orth; does this engine have a proper grounding strap fitted from the generator to the rear panel?
PS. Some images of the setup of this engine would be very helpful.

 

[Vitesse]

That's a diode tester. It doesn't have a buzzer on this meter but you can imagine how many different meters I have being an electrician. I was previously a electronics technician in the Air Force working on missiles and radar, so fingers crossed I can work out a Fiat 500 electrics but you never know?

Mario told me that he bought his meter from Screwfix and when I looked on their site I saw the one in the picture and ask if it was the one he had? It's a great little meter and was less than £10 so I bought one. The MFT I use for work cost £500.00 so I couldn't resist a bargain.

 

[fiat500]

That's a diode tester. It doesn't have a buzzer It's a great little meter and was less than £10 ....I couldn't resist a bargain.

Whatever it is, I have a "Draper" meter which is almost certainly a re-badged and re-styled version of the same. That setting does buzz very quietly on mine and works as a continuity tester in any case.
The only fault I have with my cheapo is that it would help if it had an optional set of small crocodile-clips.:bang:

https://www.toolstation.com/shop/p98689?table=no

 

[Vitesse]

The other thing that is confusing me on the voltage results Mario posted is he says he only had one red wire on terminal 30 on the fuse Box? On the F it should have two.

On the F wiring it's slightly different to the L. The feed comes from the battery + to the starter motor, then a brown lead to the voltage regulator terminal 30 then a red wire to the fuse box terminal 30, then another red wire from the same terminal up to the ignition, not via a fuse. Then from the ignition it's a light blue wire from the switched side of the ignition to the speedo. On the speedo terminal another light blue down to the fuse box terminal 15/54. Then off the same terminal on the fuse box another light blue runs to the back of the car to the coil + terminal. So it's not fused at all. You can see the wires in the picture below, the red and the light blue are the ones doing all the work. Thinking about it now there is a simple bypass of the ignition switch you can do without touching the ignition switch. Crumbs you could start one of these in seconds without the key.

All the voltage results that he got earlier today make sense, the voltage is a little low but the battery probably needs a charge up. The voltage drop on the blue wire at the ignition switch will be because of the load taken by the dashboard lights.

 

[fiat500]

True, it's easy to start a Fiat 500....Except for Mario's. We've even given clear instructions on the Forum how to open the bonnet!
To be fair, once one decides not to start I find it's not as clear cut as "if you have a spark at the right time, petrol an compression, it will go".
Lots comes into play after all this trying, not least the state of the battery, as you said.

 

[kampo]

The other thing that is confusing me on the voltage results Mario posted is he says he only had one red wire on terminal 30 on the fuse Box? On the F it should have two.

On the F wiring it's slightly different to the L. The feed comes from the battery + to the starter motor, then a brown lead to the voltage regulator terminal 30 then a red wire to the fuse box terminal 30, then another red wire from the same terminal up to the ignition, not via a fuse. Then from the ignition it's a light blue wire from the switched side of the ignition to the speedo. On the speedo terminal another light blue down to the fuse box terminal 15/54. Then off the same terminal on the fuse box another light blue runs to the back of the car to the coil + terminal. So it's not fused at all. You can see the wires in the picture below, the red and the light blue are the ones doing all the work. Thinking about it now there is a simple bypass of the ignition switch you can do without touching the ignition switch. Crumbs you could start one of these in seconds without the key.

All the voltage results that he got earlier today make sense, the voltage is a little low but the battery probably needs a charge up. The voltage drop on the blue wire at the ignition switch will be because of the load taken by the dashboard lights.

Hey Tony jjacob and friends

After my last frustrated post and today s test I gave in and went to see the fiat specialist Tony had recommended
Very good guy and very helpful he had his side kick come over to help me start the damn thing
The guy replaced the final lucas coil I bought only to then be able to get a spark at the HT king lead and the points so the two reviouscoila were not good t seems
Having said that we still can't get the dean thing started- now there is spark but it still won't start
He checked timing he replaced the condenser once again plaid with the fuel adjustment on the carb yet no luck
He said he think the fuel pump may not be producing high pressure but I can see and smell fuel overflowing the carburettor as well as reaching it
The fuel pump was put new about 1.5 year ago and it was working

Dunno what to do but feeling a bit better the mechanic could not even start it-he wants to change the HT leads and possibly the fuel pump and he believes that this would start it

Any ideas suggestions here as I also don't want to be spending too much here for mechanics epecially as I can do things myself generally IT this fiat this fiat seems to have beaten me

I attach pictur of my fuse box and cables

 

[Vitesse]

Oh well at least you got a spark now Mario and glad to hear my suspicion on the coil being faulty proved to be the culprit.

I think you are better off sticking with the mechanic for now as it could be a lot of things causing the starting problem now you have the spark back. Did it attempt to fire at all or was it just the starter spinning? I would have been tempted to try and bump start it.

To me it looks like that red wire in the fuse box is quite new, so someone has been tampering around inside there which would explain why there is only one red wire.

Tony

 

[Paolo66]

Where in the UK are you Mario? If you are close to someone on here they could maybe come and help you and/or lend you the parts first before you spend money on parts you don't need. For instance I have two fuel pumps that both work and 2 sets of leads that work. I am in Colchester if that's any good?

Damian

 

[kampo]

Hey daman i m in central london kings cross and would love to have the ability to lend test parts vefore spending more money..ideally tomorrow but any other day may work if anyone is around the area or in London generally

 

[kampo]

Nahhh Tony just starter spinning as before...he played with the timing a bit as i was soinnig and i could hear the noise changing a bit but to no avail unfortunately..
I may attempt to bump start on my own tomorrow but if for instance its the fuel pump like he thinks am not conivnced it ll start again but it may start and die off not sure