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[stigster]

Gents, And no doubt a few Ladies

I am now the proud owner of a 51 plate 3.1Td Grand Cherokee and so far, not more than 60% of it has worked simultaneously.
The latest issue is the injectors,or at least thats what I think it is. I have poor starting, Lots of smoke on start up (blue), lack of power and poor fuel economy.
I have changed the glow plugs and built a new harness for them so thats out of the question, all now drawing around 15 amps each, changed the oil and filter, changed the fuel and air filter, cleaned the charge air cooler and EGR. Im certain its not oil from the valve seals either, I know the smell of burnt oil, its definitely fuel:017:
My Question is, are the injectors from the 2.5Td VM Motori engine used  in the ford (frog Eyed) Scorpio the same, albeit, short of 1 in number? If so, it would work out a lot cheeper to get hold of them rather than the £500 I have been quoted for a set for the GC.
Thanks Stig
Lots more questions to follow.

[Dave The Sparky]

Blue smoke is oil, unburnt diesel is black smoke unless you are using Biodiesel in which case 

[Dave69]

you should be able to take the injectors to a bosche diesel place and get the cleaned and reset. i did the same with mine when i had a oil burner heap. guy charged me 25 notes each for the work. most were down on pop pressure due to carbon build up. once reset the jeep ran fine.

injector wise i think they are slightly different, i had a jeep engine and a rover lump, which was slightly different and the injectors were not the same. talk to the vm specialist in sheffield as they should be able to help. number is easy to find on google

[bgbazz]

you should be able to take the injectors to a bosche diesel place and get the cleaned and reset. i did the same with mine when i had a oil burner heap. guy charged me 25 notes each for the work. most were down on pop pressure due to carbon build up. once reset the jeep ran fine.

injector wise i think they are slightly different, i had a jeep engine and a rover lump, which was slightly different and the injectors were not the same. talk to the vm specialist in sheffield as they should be able to help. number is easy to find on google

   George at VM specialists will know. Failing that, I have a very good mate over here who is a Bosch specialist and he has a very modern (like 6 month old) injection test and repair facility. More like an operating theatre, with sterile areas and filtered air etc.

[carljh]

my 3.1TD failed the MOT due to smoke, cured by putting diesel 44k cleaner straight into the fuel filter
by the garage, runs fine now, passed with just advisories on most of the ball joints!
the No1 injector with the wire I was told can't be reconditioned like the rest, just have the seals replaced.

[Dave69]

the No1 injector with the wire I was told can't be reconditioned like the rest, just have the seals replaced.

the ecu measures the resistance across the two wires, if the value is between the acceptance limits then its fine, if the resistance is outside these limits then its limp home mode.

the wires on these go hard and brittle, if the resistance measured is too low a resistor in line can be used to fool the ecu into running correctly.

or short the connection with a resistor to give the correct reading and not use the injector (didn't try that)

[stigster]

Hi Guys

Well, I have had the injectors serviced by a Bosch dealer up here in Lowestoft, £200 for the lot, which I thought was not too bad really.
It didnt make the slightest bit of difference, still smokes on start up and lumpy for the first few moments.
I have put an amp clamp meter on the feed to the glow plugs and im only drawing 12 amps dropping to 10 amps after 20 seconds or so. The glow plug light stays on for around 15 seconds which I feel is too long.
I have checked the continuity of all of the plugs (fine) checked the feed from both relays(fine) checked the feed all the way to the plugs(also fine).
Im going slightly bloody mad now.
Does anyone have any ideas?
Im convinced its not low compression as once started it runs fine with no smoke and pulls like a train.

[Dave69]

why do you think 15 seconds is too long?

[LairdScooby]

Sounds like the rings to me  have you done a compression test on it?

For the record, blue smoke occurs when fuel and oil is burning together, when it's only oil it's white/pale grey (witness when a vehicle has a dead turbo and neat oil is being burnt through the turbo/exhaust manifold) and black smoke is excess fuel.

As for the glow plugs, they should take about 30-40A each initially, dropping to 12-15A after a short period of time. If they are drawing less then that could be why the glow plug light is staying on for so long as the glow plug timer isn't sensing the drop in current signifying they are up to temperature. Fifteen seconds is possibly a little excessive unless the engine and ambient temperatures are extremely cold.

As a rule of thumb, the "amp clamp" current meters aren't terrifically accurate on DC measurements and the best way is to fit an ammeter in series with the glow plugs. However, finding one capable of reading 200A isn't easy or cheap.

Going back to the symptoms, if it's blue smoke on start up and runs lumpy then the blue smoke suggests a mix of oil and fuel and the lumpy running suggests the cylinders that aren't firing properly are building compression. Before you go totally insane, i would suggest a compression test and then repeating it with a drop of engine oil dropped down the bores beforehand. If it improves dramatically with the oil then it could well point to the rings.