Advice needed 1980 380E

[optimusprime]

I would start with a new set of spark plugs ....but it looks like fuel related to me .

 

[Kerabo]

I would start with a new set of spark plugs ....but it looks like fuel related to me .

It’s def fuel related
It starts every turn of the key but soon spits and splutters and stops.
I wanted to find the pump relay so I can give the pump a continuous feed as a test as it seem to only run after the key is turned off snd then back on.

 

[optimusprime]

This is for 1984 380SL it might be the same ,look at the rear of the glove box

 

[Kerabo]

This is for 1984 380SL it might be the same ,look at the rear of the glove box View attachment 161645

Thanks for that
Never noticed anything but will have a better look and take some pictures

 

[Kerabo]

This is for 1984 380SL it might be the same ,look at the rear of the glove box View attachment 161645

This is a picture on the one I am looking at

 

[carat 3.6]

If this is a model with twin fuel pumps have you checked both are working?

 

[Kerabo]

If this is a model with twin fuel pumps have you checked both are working?

From the wiring diagram I can only see one pump.

When I remove the pipe at the injection pump there is plenty of pressurised fuel stored up.

 

[carat 3.6]

From the wiring diagram I can only see one pump.

When I remove the pipe at the injection pump there is plenty of pressurised fuel stored up.

I ask because alot of k-jet cars run twin pumps to get enough fuel pressure, the symptoms you describe are what happens when one of them drops out. Only way to know for sure is to get under the rear of the car and check.

 

[Kerabo]

I ask because alot of k-jet cars run twin pumps to get enough fuel pressure, the symptoms you describe are what happens when one of them drops out. Only way to know for sure is to get under the rear of the car and check.

I will look into that Thanks
When I undo the feed pipe at the injection pump there is a lot of stored pressure. I read there is an
Accumulator with a big spring it backs up the pressure.

I am starting to wonder if the chap on YouTube may be correct. It seems the injectors are all under constant pressure all of the time. The vapour just sits in the mainifold until the valve opens.So if one or two are just squirting to feed just those cylinders maybe no fuel reaching the rest?

 

[Bellow]

I am starting to wonder if the chap on YouTube may be correct. It seems the injectors are all under constant pressure all of the time. The vapour just sits in the mainifold until the valve opens.So if one or two are just squirting to feed just those cylinders maybe no fuel reaching the rest?

That theory should be testable by removing spark plugs. If your theory is correct, expect the plugs to appear different to each other.

 

[Kerabo]

That theory should be testable by removing spark plugs. If your theory is correct, expect the plugs to appear different to each other.

That’s true

 

[Kerabo]

Still trying to sort this car.

It’s been stood a couple of years and it seems it’s common not to start and run well after this.

When you turn the key to start it fires and runs for about 3 or 4 seconds.

I can keep it running in a fashion by squirting fuel direct into the intake.

I have checked the electrical system and even when it won’t start the coil has power so pretty sure it’s not electrical.

I put 2 cans of injector cleaner in the system and worked it through and let it stand a week but it made no difference.

Even when it won’t run there is lots of fuel under quiet high pressure to the fuel pump.

Today I removed 2 injectors just to test and see if they could be blocked with carbon but blowing an airline into them and it sprayed out.

One thing I thought about was it has a cold start device that appears to squirt fuel direct into the manifold.
I was thinking if this is faulty maybe there is no cold start? It has an electrical pulse as the book says but unsure if the valve works.

Any ideas ?

Failing that anyone know of a specialist on this system ? I am located Spalding Lincs

Thank you

 

[Kerabo]

Still trying to sort this 1980 380E

It’s been stood a couple of years and it seems it’s common not to start and run well after this.

When you turn the key to start it fires and runs for about 3 or 4 seconds.

I can keep it running in a fashion by squirting fuel direct into the intake.

I have checked the electrical system and even when it won’t start the coil has power so pretty sure it’s not electrical.

I put 2 cans of injector cleaner in the system and worked it through and let it stand a week but it made no difference.

Even when it won’t run there is lots of fuel under quiet high pressure to the fuel pump.

Today I removed 2 injectors just to test and see if they could be blocked with carbon but blowing an airline into them and it sprayed out.

One thing I thought about was it has a cold start device that appears to squirt fuel direct into the manifold.
I was thinking if this is faulty maybe there is no cold start? It has an electrical pulse as the book says but unsure if the valve works.

Any ideas ?

Failing that anyone know of a specialist on this system ? I am located Spalding Lincs

Thank you

 

[Bellow]

Still trying to sort this car.

It’s been stood a couple of years and it seems it’s common not to start and run well after this.

When you turn the key to start it fires and runs for about 3 or 4 seconds.

Getting fuel.

I can keep it running in a fashion by squirting fuel direct into the intake.

Not getting fuel.

One thing I thought about was it has a cold start device that appears to squirt fuel direct into the manifold.
I was thinking if this is faulty maybe there is no cold start? It has an electrical pulse as the book says but unsure if the valve works.

Cold start devices and the fuel pump relay appear to be the two most troublesome aspects of KE Jetronic. What I'm not understanding is that it fires and runs for 3-4 seconds if the cold enrichment isn't working - which is implied by it only running thereafter while cold if force fed fuel. Maybe cold enrichment is being switched off when cranking ceases?

 

[carat 3.6]

Still trying to sort this car.

It’s been stood a couple of years and it seems it’s common not to start and run well after this.

When you turn the key to start it fires and runs for about 3 or 4 seconds.

I can keep it running in a fashion by squirting fuel direct into the intake.

I have checked the electrical system and even when it won’t start the coil has power so pretty sure it’s not electrical.

I put 2 cans of injector cleaner in the system and worked it through and let it stand a week but it made no difference.

Even when it won’t run there is lots of fuel under quiet high pressure to the fuel pump.

Today I removed 2 injectors just to test and see if they could be blocked with carbon but blowing an airline into them and it sprayed out.

One thing I thought about was it has a cold start device that appears to squirt fuel direct into the manifold.
I was thinking if this is faulty maybe there is no cold start? It has an electrical pulse as the book says but unsure if the valve works.

Any ideas ?

Failing that anyone know of a specialist on this system ? I am located Spalding Lincs

Thank you

Did you check to see if it has twin pumps?

The cold start injector wont stop it from running, in this country it is rarely used anyway.

When it does run, is it on all cylinders?

Take a look at the rubber connections under the air flow meter, is there a air leak there?

 

[Kerabo]

Getting fuel.

Not getting fuel.

Cold start devices and the fuel pump relay appear to be the two most troublesome aspects of KE Jetronic. What I'm not understanding is that it fires and runs for 3-4 seconds if the cold enrichment isn't working - which is implied by it only running thereafter while cold if force fed fuel. Maybe cold enrichment is being switched off when cranking ceases?

Thanks for the reply.
The Haynes manual says the cold start device gets a pulse that varies depending on the Temperature .
Not fully understanding it but I do see my test lamp connected to its wires flash when cranking.
I am tempted to make a connector and give the cold start a direct feed?

From what I can gather, when cranking it overrides the safety system and lets the pump work. I think an oil pressure switch then tells it that the engine is running and lets it pump fuel.

Even when it stops there is lots of stored fuel under pressure. There is a storage accumulator somewhere.

Thanks Ken

 

[Kerabo]

Did you check to see if it has twin pumps?

The cold start injector wont stop it from running, in this country it is rarely used anyway.

When it does run, is it on all cylinders?

Take a look at the rubber connections under the air flow meter, is there an air leak there?

Not sure about twin pumps ? You mean the supply pump from the tank?
The wiring diagram only shows one but these seem to differ country to country.

It does run on all cylinders but only for a few seconds. That’s why I was thinking the cold start could be supplying it’s only fuel. I think I will carry on and remove all the injectors and fit new rubber seals as they are starting to perish even though I don’t think this is the problem

Thanks Ken

 

[Bellow]

Thanks for the reply.
The Haynes manual says the cold start device gets a pulse that varies depending on the Temperature .
Not fully understanding it but I do see my test lamp connected to its wires flash when cranking.

Is that flashing still present when you quit cranking but keep it running by force feeding it?...

I am tempted to make a connector and give the cold start a direct feed?

....if not, I'd consider the above - just be careful that a continuous (not pulsed) supply doesn't somehow overwhelm it.

 

[Kerabo]

Is that flashing still present when you quit cranking but keep it running by force feeding it?...

....if not, I'd consider the above - just be careful that a continuous (not pulsed) supply doesn't somehow overwhelm it.

The way I read it the flash depends on the temp outside.
Nothing when it’s not cranking but I have to make better connections.

Will have a YouTube search

Thank you

 

[Bellow]

Any use?