Bad starting, help!! Loose wires!!

taLL · Feb 23, 2013

Any suggestions on what it might be if not the glow plug circuit?
the car starts fine when the glow plug light comes on (then off), but when there is no light (and its definitely cold enough for it to come on) then it struggles to fire, and gives a large plume of white smoke out the rear when it does finally fires ,(unburned fuel?)

hd3 · Feb 23, 2013

" The Engine Coolant Temperature (ECT) sensor is a thermal transistor, which means it allows less electricity to pass through the sensor the warmer it gets. "

( Fuel Injection Technical Library Engine Coolant Temperature Sensor (ECT) )

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so if there's higher resistance .. due to corrosion/dirt on the wiring connector ..
corroded wiring .. .. .. voltage leakage from old wiring insulation .. ..
or the sensor has had it's day and won't pass the voltage ..

it's going to register as warmer coolant than it actualy is ..

meaning the glow-plugs won't fire up ..

~~~~~~~~~~~~~~~~~~~~~~

according to that m47r .pdf ..
if the coolant sensor is knackered ..
the ecu uses the reading from the air-intake-temp-sensor as a substitute

~~~~~~~~~~~~~~~

and gives a large plume of white smoke out the rear when it does finally fires

that would be the 'norm' if glow-plugs weren't being used

be a fair few 'how-to' s .. via google .. on testing a coolant temp sensor with a multi-meter

taLL · Mar 13, 2013

I have been using the car for a while now since i changed the glow plugs, and have realized that my starting problem only seems to be when warmish, cold starts are no problem, hot starts are no problem (fire 1st turn of the key without any throttle) but when the car has sat for an hour or two then is struggles to fire.

I have done a leak back test on the injectors this morning, without turning over engine. I clamped the leak back pipe and remove the T piece from the top of each injector. There was a small amount of fuel in each injector, after switching the fuel pump on about 12 times (seems to switch of after about 30 sec). Is this normal? or should they stay BONE DRY?!

what els could it be, given my symptoms have changed since the glow plug change (also changed battery)

I have a new engine coolant temp switch to fit but i no longer think that is the problem.

Any help would be great.

taLL · Mar 13, 2013

O.K. Ive just done a leak back test at high pressure.
Removed the injector plugs, and remove and clamped the leak back pipe.
cranked the engine and watched the injectors, all were pooling a little fuel in the top but none were spitting, spluttering or squirting, all seemed to look the same.
I assume this is good/normal?

john t · Mar 15, 2013

taLL said:
Would that go to the same junction box as the glow plug leads though ?

its the connector for the erg vacuum solenoid, in your pic it shows you have an erg bypass fitted, so connector wont be needed,

john t · Mar 15, 2013

taLL said:
I have been using the car for a while now since i changed the glow plugs, and have realized that my starting problem only seems to be when warmish, cold starts are no problem, hot starts are no problem (fire 1st turn of the key without any throttle) but when the car has sat for an hour or two then is struggles to fire.

I have done a leak back test on the injectors this morning, without turning over engine. I clamped the leak back pipe and remove the T piece from the top of each injector. There was a small amount of fuel in each injector, after switching the fuel pump on about 12 times (seems to switch of after about 30 sec). Is this normal? or should they stay BONE DRY?!

what els could it be, given my symptoms have changed since the glow plug change (also changed battery)

I have a new engine coolant temp switch to fit but i no longer think that is the problem.

Any help would be great.

possibly the cam shaft sensor, they have a habit of going oc when warm

taLL · Mar 15, 2013

does the cam shaft sensor fault not usually make the starting worse the hotter the engine gets though? as mine is only bad at starting when warm, when its hot or stone cold, there is no problem starting.

I egr valve isn't bypassed as far as i know.

john t · Mar 19, 2013

yes , problematic when the sensor gets warmed,but nothing is ever certain , could be an intermittent fault,
you have a choice, you can suffer continual uncertain starting problems or start to eliminate known problems, i think the camshaft sensor is about £40 takes 10 mins to fit.
or take it to a garage and you wont see much change from £300

just realised the photos that you posted were not of your actual car, so cant help regarding the connector

taLL · Mar 22, 2013

the first 2 photos are what i took of my car.

it went into the garage yesterday for diagnostics, came back with a few alarms these have now been cleared as they were probably due to me taking plugs off ect. need to drive it for a few days now and go back and see if any new fault codes have come up relating to the current fault.

Bad starting, help!! Loose wires!!

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