Engine Won't Start

[Guest matvic]

After months of not being able to start the engine, despite fuel, spark, air and timing all OK (Pinto 2.0 with DGAV Webers), it started yesterday by holding a rag over the air intake to the carb. Battery has died due to the number of times I have tried to start the car. Today with a new battery, same thing. Car won't start, but as soon as I put a rag over the air intake it started fine. Once it has been running for a few in minutes it then starts fine every time, while it is hot.

Any ideas why or what to do?

Thanks

[maccavvy]

does it have a choke??

[Guest mdav1970]

I took the choke completely off as never used it

 

I usually pump the pedal 6-10 times before starting and then it starts straight up.

 

Manual or electric pump?

[Guest matvic]

does it have a choke??

It has an automatic choke and the butterflies are closed when cold and open when hot, seems to function ok.

[Guest matvic]

I took the choke completely off as never used it

 

I usually pump the pedal 6-10 times before starting and then it starts straight up.

 

Manual or electric pump?

Manual pump, but I still couldn't start it with lots of pumping/no pumping/spraying cold start/spraying petrol directly in etc

[Guest mdav1970]

Strange, if you left it a while in case of flooding, sprayed cold start in,it still wont start or even attempt to?

[Guest matvic]

Strange, if you left it a while in case of flooding, sprayed cold start in,it still wont start or even attempt to?

Yep, have tried leaving it, cleaning the plugs, it doesn't even pop or splutter.

[Guest mdav1970]

You defo have a strong spark?

[Guest matvic]

You defo have a strong spark?

Nothing to compare with, it's a yellow/white spark, should it be bluer?

[Big Jim]

There is possibly a ballast resistor in the +ive lead to the coil, (check Haynes) what this does is allows 12v for starting, but as soon as it fires, it drops to 9v to the coil, these are notorious for going duff, and will give you the weak yellow spark making it hard to start.

 

Also remove the air filter, if you see fuel being squirted into the manifold when the accelerator is pressed, then that confirms that it's not fuel related

[Guest matvic]

There is possibly a ballast resistor in the +ive lead to the coil, (check Haynes) what this does is allows 12v for starting, but as soon as it fires, it drops to 9v to the coil, these are notorious for going duff, and will give you the weak yellow spark making it hard to start.

 

Also remove the air filter, if you see fuel being squirted into the manifold when the accelerator is pressed, then that confirms that it's not fuel related

Thanks for this, I have tested and it drops to 9v whilst still trying to start. I thought I had an non-ballast system and can't see a ballast resistor. I think I have put a non-ballast coil in. There is something on the wire to the +ve of the coil, but I was told it was a capacitor to smooth the signal to reduce any interference for radios etc. Currently I have removed this and wired directly to the coil. There are two wires going to the +ve of the coil...implying ballast?

 

Have just tested again, with the ignition on the +ve is 12v. When trying to start it drops to 9v. This seems to be the wrong way round?

 

Fuel is fine, I can see it going in,

Edited April 2, 2016 by matvic

[theduck]

Worth putting new plugs in as yours will have got wet with petrol by now.

[Big Jim]

The later ballast resistors didn't look like a component, just a thick part of wire.

Try running a 12v wire to the coil and see if that makes any difference. depending on the year of the donor ignition, and which wiring harness you have in, one of the 2 wires could go to the tacho (In the Haynes manual, and ford colours, it's the green one)

What ignition system are you using? points? Ford electronic dizzy? type of ignition ECU? what year is the car based on?

Edited April 2, 2016 by Big Jim

[Guest matvic]

OK, recharged the battery overnight and ran a 12v to the +ve coil and it dropped about 4v during (15v - 11v), but wouldn't start, I then used the rag method to start it, and the coil is at 9v at 3000rpm. I am now thinking I need a ballast coil. I checked the resistance of the new coil, about 5 ohms. The old coil I took off is 1.6 ohms. Again does this indicate a ballast coil? What is the effect of having a non ballast coil if I should have a ballast one?

The two wires from the +ve coil are green and green with a black stripe.

Ignition is a Bosch ford electronic dizzy from a Sierra, but the engine is a RS2000 (1973)

Thanks for your help, I am learning loads

Edited April 3, 2016 by matvic

[Guest matvic]

Put the old coil on and am getting different voltages!

New Coil (5.6ohms) = 12v ignition on, 9v whilst starting, 6v at tickover, 9v at 3000rpm

Old coil (1.6ohms) = 12v ignition on, 10v whilst starting, 12v at tickover, 12v at 3000rpm.

Neither will start it from cold, but both will start it hot.

Looked at Haynes and the two leads are for 1.3 and 1.6, I had a 1.6, changed the engine, but nothing else. However, it has worked fine for the last two years.