It starts!! .... but it won't stay started

[Donnysoutherner]

Bummer! the car is back together following it's full body off (soory about the lack of photos, I'll get some on soon). However after a bit of trial and error the car will start but instantly stops again, after maybe 2 seconds. For the time it is going it sounds great, firing properly, even roaring like it should (been a long time since I heard that). Options are (I reckon):

1) Fuel starvation: Pump is pumping and pressurising the injectors (I hear it wurr as the ignition goes on). I have disconnected and powered the pump and it looks to pump well, but is there some reason why it might cut out? Some kind of regulator which might be faulty?

2) Electrical: Ignition seems to be good and while it runs it sounds great, but again is there somthing telling it to stop? It does stop almost as if the ignition was turned of, so what could that be?

There is one thing possibly, that is a little pink box. In the wiring diagram in the 'Bible' it is described as 'pink engine run sensor (photo will follow). it appears to connect to the pump via the loom as well as other things. On the bottom it says 'Relais Benzinpumpe' which (I guess means) fuel pump relay. the cover came of thios and clearly it has had water in at some stage. however if this was the problem I would think it wouldn't start at all.

My experience on engines is all 4 cylinders and carburettors. Anyone out there know more than me? It's an S1 by the way so no ECU's, yellow connectors etc!

HELP PLEASE!!!

[GreenV8S]

Stick a meter or test lamp across the fuel pump. From the symptoms I suspect that the pump is being switched off a couple of seconds after you start cranking. In that case I'd look for the engine running signal from the ignition module to the fuel pump relay (I don't know how it's arranged on that model - on the V8 it is managed via the ECU but somebody said there's a little circuit on the relay panel that does this on the V6 models. In any case it's somewhere to look if the pump is cutting out.

If the pump is staying powered up until the engine dies, check the coil +ve voltage. This will probably be at 12V all the time the ignition is on. If you see 6V then you have a ballasted ignition system which can produce symptoms like this. On a ballasted system there are actually two +ve supplies to the coil. The main supply goes through a dropping resister so you get 6V at the coil. But there is also a 'cranking' circuit fed directly from the starter motor circuit which supplies battery voltage (around 9V) while the engine is cranking.

[Last S4]

I know how ridiculous my suggestion is but.......
How long has the car been sitting with the same fuel? I had a 205 Mi16 which I sold recently as a non runner. It would start but instantly stop, it drove me nuts. The spark was fine, fuel pressure fine etc etc. I spent hours not finding a fault.
When the car was then taken on a transporter to the new owner it started and ran no problem at the other end of its journey. I put it down to the seperation of fuel in the tank after sitting for a couple of years. Of course a loose connection etc could be the culprit but the problem has not re-emerged.

[Barkychoc]

Does it fire when you are turning it on the starter but as soon as you release the key it dies? If so sounds like an electrical supply issue - ignition is powered by a seperate circuit when you are cranking the engine on the starter.

[Donnysoutherner]

Thanks for the pointers, will test out later, however the bad news is that it now does not start at all!

Pump is still priming the system, but whereas previously starting on very little key (and remaining going after starter disengaged), now lots of key and no start. The starter is new and as Barkychoc suggests, I think there is is some kind of ballast circuit coming from it. Had to adapt wiring to fit as replacement starter is a newer version, but I'm sure the adaption is right (??? famous last words).

Fuel is new as tank had been drained and removed. Have thought about impurities in the system but all new filters etc. if fuel 'muck' was the problem, it would not have run so cleanly.

Still thinking faulty cutout or circuit either affecting fuel supply or working on the ignition direct.

[Donnysoutherner]

This is the 'pink relay'.





In the bible, the wiring diagram shows a 'pink engine run sensor', but the wiring does not look right for this to be it (I can't find anything else though that fits the bill). It also lists a 'green hot start relay' and the wirng looks right and the connector is green. However, on the bottom of this part it says it is a 'benzinpumpe relais' (I don't do languages but I reckon it is fuel pump relay!) It is a Ford part. No fuel pump relay shown on the S1 wiring diagram!

It is exactly where it was before body off (even with replacement connection as shown)and ran perfectly well. Is it a previous owner bodge or a TVR bodge??

Any ideas? I know there's not too many S1 experts out there.

[Gerald-TVR]

Be aware even the Steve Heath bible says the wiring diagrams are 'indicative'

[Barkychoc]

Donnysoutherner said:

Had to adapt wiring to fit as replacement starter is a newer version, but I'm sure the adaption is right (??? famous last words).

I'd focus on this - the starter solenoid feed is probably wired as part of the ballast circuit so if you've missed a wire off or got it on the wrong terminal that could be the reason.

Whip a plug out - if its wet with fuel you've flooded it. You'll have to take them all out and dry with some heat if so (e.g. a blowlamp).
When you restart hold the accelerator to the floor - that gets the maximum amount of air through the engine to dry it out. You may end up drying the plugs more than once.

[Donnysoutherner]

Ok, the latest find is a blowing fuse, this has been replaced and blows again when ignition is turned (without engaging starter). On wiring diagram it is the 15 amp between ignition switch and tacho. From tacho, circuit goes through loom connection to cold start resistor (no idea where this is on car!) to +ve on coil. But guess what; also goes to starter motor connection as part of this circuit!

Might be getting somewhere, but don't really understand why it would ever have started?

Will look again at starter connections.

[GreenV8S]

Donnysoutherner said:

Ok, the latest find is a blowing fuse, this has been replaced and blows again when ignition is turned (without engaging starter). On wiring diagram it is the 15 amp between ignition switch and tacho. From tacho, circuit goes through loom connection to cold start resistor (no idea where this is on car!) to +ve on coil. But guess what; also goes to starter motor connection as part of this circuit!

Might be getting somewhere, but don't really understand why it would ever have started?

Will look again at starter connections.

That description sounds a lot like a ballasted coil supply. If I were you I'd focus on the behaviour at the coil. Especially, locate the unballasted circuit from the starter motor to the coil and find out what happens to it when the starter motor is disengaged. You might find you need a diode in that circuit to stop the coil +ve from being pulled down to earth (and blowing the ignition fuse) when the starter is disengaged. Whether you need it depends on the relative resistances of the ballast resister and solenoid primary circuit, which you could have affected if you've replaced the starter.

[Le TVR]

In theory (well on mine anyway)

Ignition RUN position:
- 15A fuse
- Feeds Tacho + Ignition Amplifier module + Ballast resistor

Ignition START position:
- Feeds Starter soleniod + Ballast resistor/Coil connection

If the 15A fuse is blowing there is possibly a short in the loom around the ballast resistor or ignition amp.
Disconnect the two plugs to the ignition amp and unplug the tacho and start checking the wiring.

The best tool is a 12V bulb on a pair of long wires. Connect one end to the battery +
Connecting the other end to suspect wire will light the bulb if that wire is shorted to ground.

The ballast resistor looks just like a single thick wire with bullet connectors at each end. It is often tie wrapped to the upper chassis rail on the LHS of the engine. Sometimes it is coiled, sometimes not...

[Donnysoutherner]

Le TVR said:

In theory (well on mine anyway)


The ballast resistor looks just like a single thick wire with bullet connectors at each end. It is often tie wrapped to the upper chassis rail on the LHS of the engine. Sometimes it is coiled, sometimes not...

Le TVR, you are my favourite person!!! In refitting and tarting up wiring I have removed what I thought was a wiring 'bodge' which from your description is my ballast resistor! That would therefore likely be the problem.

The problem is that was some weeks ago on the rebuild and it is now missing! Does anyone have a Ballast resistor going spare, or know where i can get one???

[Barkychoc]

You could just bridge it with a bit of wire to test it - but running it like that long term will cook the coil I'd have thought.

[tozerman]

Barkychoc said:

You could just bridge it with a bit of wire to test it - but running it like that long term will cook the coil I'd have thought.

You could always do what Chris suggested and change the coil for a 12v item, more expensive but easier to get hold of I would have thought

Cheers.....Tony..

[Donnysoutherner]

Barkychoc said:

You could just bridge it with a bit of wire to test it - but running it like that long term will cook the coil I'd have thought.

Do you think I might have already 'cooked' the coil? The first problem i had was car starting and stopping within 2 seconds, now not starting at all.

[Donnysoutherner]

...because I removed the resistor and simply reconnected the circuit without it. Is there and easy test for the coil?

[Barkychoc]

I think it would take some time to be honest.

Have you taken a plug out to see if it is wet with petrol.
It will never start if they are wet, it won't even try.

[Donnysoutherner]

haven't checked plugs as yet, but definitely need to replace ballast resistor before i do anything else, hopefully that will stop blowing fuse. But noted, will check before I try starting again.

Think I've found relevant resistor on ebay, says it's for a Fiesta but I guess ther's not many different ones! certainly looks the same, however ohm rating not stated (question asked) and in any case I don't know rating for mine anyway. Again, note the advice above on that.

[Le TVR]

Ballast resistor with the Duraspark unit should be 1,3 ohms.
If you can't find the Ford part then try RadioSpares part no 107-4080. This is a 1,2 ohm ceramic power resistor which should be close enough.

[GreenV8S]

Donnysoutherner said:

...because I removed the resistor and simply reconnected the circuit without it. Is there and easy test for the coil?

Disconnect the coil electrics from the car but leave it mounted. Connect 12V supply to the +ve terminal. Connect a spark plug to the HT terminal using one of your HT leads. Get a wire connected to earth at one end and briefly dab it on the coil -ve terminal. By 'briefly' I mean a fraction of a second. You will overheat the coil very quickly if you leave it connected. You should see a spark at the spark plug each time you do this. If you don't see the spark, it proves the coil is dead.