Technical FIAT Stilo 1.9 JTD NOT Starting (only start spray)

[lowridersi]

Hello All

So just joined the forum as i am out of options to what is going on with my 1.9 JTD 2002 and i am relay hoping someone from you guys can point me in the right direction. We had the car for the last 13 years in the family the car was good loked after regular oil changes, belts,...
The car has curently 300K KM on the clock. And the car is still running strong, with almost none oil use. SO realy for now a bullet proof engine.

I will try to describe the fault as best i can and all the thing that have been performed.

So the problem is that i am facing is that the Car is not starting when you cranking the car over. But if you add a bit of cold start spray the car jumps to life and runs as is should!

So what i did noticed before the car actually failed to start is that you could hear that the car had to crank a few times more before starting.

Tests and diganostics that have been performed:

Car battery before cranking is 13.5V When turning over the battery voltage drops to approx to 11.2 V I have tried to Start the car with jump cables from a running car and a fully charged battery, and no succes.
At the time when cranking the Pressure form the fuel pump in the tank is at 3 Bar And the fuel pressure from the bosch pump is over 300 bar when cranking. IF you are crancking the engine for a long time there is no smell of fuel from the exhaust.
So my conclusion fuel is not being added in the combustion space when cranking



I have runned dignostic and all i could come up with is a EGR Fault, but the fault is there from what i know. The EGR is also blended out just to be on the safe side.

A leak back test from injectors have been done and all of the injectors return the same amount of fuel. So none of them is "leaking"

When the car is warmed up and running no additional errors came up like RPM sensor fault or similar. So that way A fault like an RPM or crank sensor could have been discarded.

Fuel filter has been changed last year. Also if you disconnect the fuel rail to one of the injectors you can see the fuel is squirting out while cranking.

The leads that go to the ECU have been disconnected and sprayed with a contact spray just to avoid a bad contact on the ECU.

Also the car has correct Fuel in the system ONLY Diesel No Petrol 100%

Also IMPORTANT once you get the car running COLD or WARM if you try to start the car again in the next 5-15 minutes the car starts with no prob. But once you leave it settled for like an hour or so the only thing that brings it back to life is a Start spray.


Could anyone have an idea what a problem could have been i am knocking my head as i ran out of options on what to check more.


Best Regards
Lowrider

 

[flyingdutch]

Injector wiring is in order ? As i have seen those wires fail a lot in higher mileage cars

 

[Ralf S.]

If only cold-start spray makes the car start then the problem is "not enough fuel/mixture".

Your injectors sound okay and it runs fine when it's hot, so I think the "hardware" is okay when it's working.

I dunno if the beast has a temperature sensor fault and so it's not telling the ECU to "go rich" with the mixture when the car is cold, or if the ECU is getting the correct temperature reading but is not doing anything with it.

If you have access to someone knoes what they're doing, it's worth seeing if you can get the temperature sender tested. I think the one on the thermostat just supplies the temperature gauge inside the car, rather than getting involved in the engine management but I may be wrong, since I don't know where the "real" temperature sensor is, in that case (although it would be somewhere connected to the radiatore cooling fan).

If the car knows what's happening to it but the ECU has a problem dealing with the information then the problem would be "the ECU" ... But I don't know why it would randomly fail to tell the injectors when to "go rich".. so it may be a less serious problem. I don't know if the engine has a cold-start circuit that is separate from the regular mode but if it has then there may be a relay, fuse or connection in there that has stopped working properly.

Ralf S.

 

[bugsymike]

If only cold-start spray makes the car start then the problem is "not enough fuel/mixture".

Your injectors sound okay and it runs fine when it's hot, so I think the "hardware" is okay when it's working.

I dunno if the beast has a temperature sensor fault and so it's not telling the ECU to "go rich" with the mixture when the car is cold, or if the ECU is getting the correct temperature reading but is not doing anything with it.

If you have access to someone knoes what they're doing, it's worth seeing if you can get the temperature sender tested. I think the one on the thermostat just supplies the temperature gauge inside the car, rather than getting involved in the engine management but I may be wrong, since I don't know where the "real" temperature sensor is, in that case (although it would be somewhere connected to the radiatore cooling fan).

If the car knows what's happening to it but the ECU has a problem dealing with the information then the problem would be "the ECU" ... But I don't know why it would randomly fail to tell the injectors when to "go rich".. so it may be a less serious problem. I don't know if the engine has a cold-start circuit that is separate from the regular mode but if it has then there may be a relay, fuse or connection in there that has stopped working properly.

Ralf S.

Do the injectors get a signal to open as you say there is fuel in the rail under pressure?
The leak test with engine running was the volume of "leak off" within specifications?
Sorry just looked at the date!!! I assume you have fixed it