Strange breakdown & loss of power!!

I'd appreciate some help here please I had a strange breakdown in my Defender 300tdi today, resulting in loss of power and a burning electrical smell.

• Driving home in the rain today with wipers on, windscreen had misted up so I switched on my heated windscreen, suddenly wipers went really really slow.
• Stopped at traffic lights 30 secs later and engine cut out.
• Turned ignition key and just heard a horrible grating sound, engine didnt start.
• Waited a minute and tried again, this time it started.
• Drove off but noticed a distinct loss of power, couldnt get above 30mph.
• Fuel guage needle went over to full (and I think dash lights wouldnt illuminate?).
• About 3 miles later full power returned, but when coming off the accelerator to change gear, engine revs stayed on, even with foot off the pedal.

Eventually I arrived home, but I have no idea what the problem is. Seems more than a coincidence that everything went wrong when I switched the heated windscreen on. Perhaps full power returned only when the windscreen relay/timer switched off? Could burning electrical smell indicate a short in circuit? Does my Defender have an engine management system that maybe at fault?

Any ideas please before I ring the garage tomorrow?

Electronic or manual fuel pump ?

200tdi ayre said:

Electronic or manual fuel pump ?

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Sorry, I dont know. Would be whatever is fitted as standard.

LeadFarmer said:

Sorry, I dont know. Would be whatever is fitted as standard.

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More than likely manual in which case it's very confusing. It should only lose power if it is loosing fuel or air is significantly restricted or something like the timing has slipped

200tdi ayre said:

More than likely manual in which case it's very confusing. It should only lose power if it is loosing fuel or air is significantly restricted or something like the timing has slipped

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I feared the turbo had gone, so was relieved when power returned. Strange that the engine revs stayed on even when I came off the gas And the loss of power lasted about the same time it takes for the heated windscreen to switch off - about 10 mins.

Im supposed to be towing the caravan to Chester tomorrow, but I wont be doing that now.

LeadFarmer said:

I feared the turbo had gone, so was relieved when power returned. Strange that the engine revs stayed on even when I came off the gas

Im supposed to be towing the caravan to Chester tomorrow, but I wont be doing that now.

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I can only really think of causes if its an electronic fuel pump. Any chance of a pic ?

Certainly - but forgive my lack of mechanical knowledge - where is it?

200tdi ayre said:

More than likely manual in which case it's very confusing. It should only lose power if it is loosing fuel or air is significantly restricted or something like the timing has slipped

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Had the same though about electric pump...can't think why else

As for throttle sticking that has to be the cable surely......perhaps something has shorted against it and melted the plastic.....seems a big coincidence otherwise

Drivers side of the engine compartment attached to the side of the engine with 4 pipes coming off going to the injectors

Nipping out to do it now...

200tdi ayre said:

Drivers side of the engine compartment attached to the side of the engine with 4 pipes coming off going to the injectors

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FIP? I was thinking lift pump

blue beasty said:

FIP? I was thinking lift pump

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Lift pump is manual no ?

FIP autos definately had them in discos but I dunno about

was the noise the starter not having enough power to engage proper

If so Id be loking at a main Alt /starter wireing

Spunka said:

was the noise the starter not having enough power to engage proper

If so Id be loking at a main Alt /starter wireing

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Wouldn't loose power because of that or keep revs when letting off

200tdi ayre said:

Wouldn't loose power because of that or keep revs when letting off

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depens what the power shortage afects

any way i was just tossing idears around

Sounds like an earth fault to me which then shorted through the throttle cable making it stick.
Perhaps when you switched on the screen the poor earth was overloaded which caused a volt drop at the pump cut off solenoid causing it to close part way hence the power loss

200tdi ayre said:

Lift pump is manual no ?

FIP autos definately had them in discos but I dunno about

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Yes but lecky is a commonish retro fit...esp with all the dodgy pumps flooding the replacement market

200tdi ayre said:

I can only really think of causes if its an electronic fuel pump. Any chance of a pic ?

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Here we go...

owl said:

Sounds like an earth fault to me which then shorted through the throttle cable making it stick.
Perhaps when you switched on the screen the poor earth was overloaded which caused a volt drop at the pump cut off solenoid causing it to close part way hence the power loss

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thats the line i would be looking at. main power/earth faults efect every thing

Just tossing again

owl said:

Sounds like an earth fault to me which then shorted through the throttle cable making it stick.
Perhaps when you switched on the screen the poor earth was overloaded which caused a volt drop at the pump cut off solenoid causing it to close part way hence the power loss

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This is the best solution so far but still insure about throttle sticking on