Focus Mk2 1.6 Won't Start but cranks - fuel is getting to the injectors!

[Antonycc]

Hi everyone,

My focus cut out and died on a dual carriageway and it's not started since!

It will crank and fuel is getting to the injectors. I took the inlet pipes off and cranked it, and fuel spat out of all 4 injectors.

I've got DPF DTC on Forscan, but this has been there for months and the DPF isn't blocked - definitely not! 😉

I've tested the voltage of injector 1 when cranking, with a logic analyser and the voltage is 0 volts - there are no pulses. No electric is getting to the injectors to fire them.

Has anyone seen this problem before?

Antony

 

[Jordandavis]

I have the same problem with my car only brought it 2 days ago drove it fine then went to drive again broken down changed the battery thinking it was that looked at the starting motor not that checked the fuse box that’s all fine a lot of people are saying it’s the cluster for some reason 

[Antonycc]

1 hour ago, Jordandavis said:

I have the same problem with my car only brought it 2 days ago drove it fine then went to drive again broken down changed the battery thinking it was that looked at the starting motor not that checked the fuse box that’s all fine a lot of people are saying it’s the cluster for some reason 

I don't know. I went to visit it again this morning. Fuel is there, and it starts on easystart so compression is there. 

The problem is electrical. The injectors just don't fire.

Antony

[TomsFocus]

3 minutes ago, Antonycc said:

I don't know. I went to visit it again this morning. Fuel is there, and it starts on easystart so compression is there. 

The problem is electrical. The injectors just don't fire.

Antony

Crank sensor?

What is the exact DTC that Forscan shows?

Also, when was the fuel filter last changed?  The ECU won't let the injectors fire if there's not enough fuel pressure.

[Antonycc]

2 hours ago, TomsFocus said:

Crank sensor?

What is the exact DTC that Forscan shows?

Also, when was the fuel filter last changed?  The ECU won't let the injectors fire if there's not enough fuel pressure.

Here are the DTCs: (My air filter assembly is currently off)

P2459 - Diesel Particulate Filter Regeneration Frequency - Signal is Above Maximum Threshold

P0113 - IAT Sensor Circuit High Input - Signal is Above Maximum Threshold

P0100 - Mass Or Volume Air Flow A Circuit - There is no change in the signal

P0102 - MAF Sensor Circuit Low Input - Signal is Below Minimum Threshold

U1900 - CAN communication bus fault
 

[Antonycc]

2 hours ago, TomsFocus said:

Crank sensor?

What is the exact DTC that Forscan shows?

Also, when was the fuel filter last changed?  The ECU won't let the injectors fire if there's not enough fuel pressure.

The crank sensor is a 3 wire one, I was trying to test it but there was something weird which threw me off course. The feed wires were 5v, 7.4v and 0v. What on earth was going on with that? The feed wires should be 5v, 0v and 0v, surely? Why would the signal wire be 7.4v when the sensor isn't even plugged in!?!?

[Antonycc]

Fuel filter changed about two weeks ago.

[Antonycc]

Ok, so on cranking, fuel pressure is 650kpa... which is 6.5 bar...

[TomsFocus]

Has it been mapped?  I missed the DPF wink earlier lol.  If so, you shouldn't be getting DPF faults and it may be the map that's causing the issue.

[Tdci-Peter]

7 hours ago, Antonycc said:

so on cranking, fuel pressure is 650kpa... which is 6.5 bar...

Common rail diesel needs about 200Bar in the rail before the injectors will even try to operate.

Forscan run on starting my 1.8 (with no problems, just for info). But the 1.6TDCI is similar, I am fairly sure I have seen some data somewhere.

At 6.5 Bar, it does sound to me like a fuel supply problem. Most problems are in the line from tank to pump, including the fuel filter. I would kind of expect a low pressure DTC, but I know the ECU software is not great at registering DTCs before the engine actually starts.

 

However, 7.4v on the crank sensor definitely sounds wrong. May be an open circuit, and some floating voltage. Try back-probing the pin with the sensor plugged in. The ECU also needs about 200 rpm to fire up the injectors, so the crank sensor would also stop them operating.

If it cranks ok, with no odd displays or lights on the cluster, and the diagnostic system connects ok, then I doubt if you have a CAN bus problem, nor the classic 2006 Focus Cluster problem. Symptoms are completely different.

[TomsFocus]

9 hours ago, Tdci-Peter said:

Common rail diesel needs about 200Bar in the rail before the injectors will even try to operate.

Forscan run on starting my 1.8 (with no problems, just for info). But the 1.6TDCI is similar, I am fairly sure I have seen some data somewhere.

At 6.5 Bar, it does sound to me like a fuel supply problem. Most problems are in the line from tank to pump, including the fuel filter. I would kind of expect a low pressure DTC, but I know the ECU software is not great at registering DTCs before the engine actually starts.

Doh!  I replied to the 'recent fuel filter change' post without seeing the 6.5 Bar one!  Have removed mine to avoid confusion now.  6.5 bar isn't enough to do anything with as you say. 

Do you reckon it's possible the filter just wasn't bled correctly and had an air lock which shifted under high demand?  2 weeks seems a long while though.  It does also seem very odd there's no fuel pressure code when it cut out on the motorway, it's not just a non-starter. 

[Ennvoqation]

Weird as it sounds, check your Alternator. If you've got a dodgy diode that'll screw with the CANBUS and sensors. It's notorious for giving abnormal and confusing results. The best way is to get a wave monitor on it to check the pulses. If there's noise on the CANBUS then the car many not know what's going on and therefor crash out leading to all sorts of faults like no power or fuel going to the engine.

[Antonycc]

22 hours ago, TomsFocus said:

Has it been mapped?  I missed the DPF wink earlier lol.  If so, you shouldn't be getting DPF faults and it may be the map that's causing the issue.

It's not been mapped. 🙂

[Antonycc]

17 hours ago, Tdci-Peter said:

Common rail diesel needs about 200Bar in the rail before the injectors will even try to operate.

Forscan run on starting my 1.8 (with no problems, just for info). But the 1.6TDCI is similar, I am fairly sure I have seen some data somewhere.

At 6.5 Bar, it does sound to me like a fuel supply problem. Most problems are in the line from tank to pump, including the fuel filter. I would kind of expect a low pressure DTC, but I know the ECU software is not great at registering DTCs before the engine actually starts.

 

However, 7.4v on the crank sensor definitely sounds wrong. May be an open circuit, and some floating voltage. Try back-probing the pin with the sensor plugged in. The ECU also needs about 200 rpm to fire up the injectors, so the crank sensor would also stop them operating.

If it cranks ok, with no odd displays or lights on the cluster, and the diagnostic system connects ok, then I doubt if you have a CAN bus problem, nor the classic 2006 Focus Cluster problem. Symptoms are completely different.

Very useful, thanks... Will try testing with the crank sensor in place.

[Antonycc]

8 hours ago, TomsFocus said:

Doh!  I replied to the 'recent fuel filter change' post without seeing the 6.5 Bar one!  Have removed mine to avoid confusion now.  6.5 bar isn't enough to do anything with as you say. 

Do you reckon it's possible the filter just wasn't bled correctly and had an air lock which shifted under high demand?  2 weeks seems a long while though.  It does also seem very odd there's no fuel pressure code when it cut out on the motorway, it's not just a non-starter. 

It may have had a code, but when I got it back, I cleared them because I thought it would show crap about the air filter off, etc. Now because the car won;t start, I can;t get those codes back. Oh well.

[Antonycc]

Ok, an update... I've put a second hand HP pump on it... I get 10,000mpa now which is like 100bar, but it still won't start. The only DTC I get is DPF. There is still no pulse on the injectors. Why won't they fire?!??!?

[WireyWhenWet]

2 hours ago, Antonycc said:

Why won't they fire?!??!?

Not firing at all, or very weak? Are they getting a signal to fire? (Sorry if you've put this already I have weak signal and things aren't loading right...)

If they're not firing but do have a signal, are they gummed up at all? I not a recent filter change, could any crap have gone through during while change to block the nozzles up to prevent them firing and then set in place as they're compressed?

Just to double check it but a common one, are there ANY signs, no matter how slight of how much, of fuel or air escaping around that area? The seals are ridiculous sensitive to being seated properly, and are often to blame for poor fuel pressure following a change.

[Antonycc]

22 minutes ago, WireyWhenWet said:

Not firing at all, or very weak? Are they getting a signal to fire? (Sorry if you've put this already I have weak signal and things aren't loading right...)

If they're not firing but do have a signal, are they gummed up at all? I not a recent filter change, could any crap have gone through during while change to block the nozzles up to prevent them firing and then set in place as they're compressed?

Just to double check it but a common one, are there ANY signs, no matter how slight of how much, of fuel or air escaping around that area? The seals are ridiculous sensitive to being seated properly, and are often to blame for poor fuel pressure following a change.

Hi, there is no power to the injectors.

I'm getting 100bar of pressure.

There is sign of poor seals around the injectors, yes. There is fuel around them, but it's been like that for ages.

Antony

[nicam49]

Hi, check that your new pump is giving enough pressure:

 disconnect all the electrical drives to the injectors and also disconnect the electrical connection to IMV. This causes the IMV to be fully open. If you now crank the engine you should see >1050bar

[Tdci-Peter]

1 hour ago, Antonycc said:

Hi, there is no power to the injectors.

I'm getting 100bar of pressure.

I suggest a leak off test next.

I doubt if 100Bar is enough to trigger the injectors. The pressure while running varies between about 400Bar and 1500Bar, it really is very high.

There must be some fuel getting to the pump, though if there was some air (tiny bubbles) in the fuel, it would have the effect of reducing the pressure.

Leakage through the solenoid valves inside the injectors will also reduce the fuel pressure. While cranking there should be almost no leak-off from any injector. When the little valves in each injector operate, they de-pressurise a chamber in the injector, which then opens the pintle that seals off the injector nozzle. The fuel from this chamber goes to the leak-off pipes, so there should be a leak off flow while running, but not while cranking without injector pulses. A worn or damaged valve seat in an injector would cause unwanted leak-off. Hence a leak-off test can identify leaking injectors.

 

[Antonycc]

On 5/15/2020 at 10:50 PM, nicam49 said:

Hi, check that your new pump is giving enough pressure:

 disconnect all the electrical drives to the injectors and also disconnect the electrical connection to IMV. This causes the IMV to be fully open. If you now crank the engine you should see >1050bar

Thanks, I'll check this today.

[Antonycc]

On 5/15/2020 at 11:45 PM, Tdci-Peter said:

I suggest a leak off test next.

I doubt if 100Bar is enough to trigger the injectors. The pressure while running varies between about 400Bar and 1500Bar, it really is very high.

There must be some fuel getting to the pump, though if there was some air (tiny bubbles) in the fuel, it would have the effect of reducing the pressure.

Leakage through the solenoid valves inside the injectors will also reduce the fuel pressure. While cranking there should be almost no leak-off from any injector. When the little valves in each injector operate, they de-pressurise a chamber in the injector, which then opens the pintle that seals off the injector nozzle. The fuel from this chamber goes to the leak-off pipes, so there should be a leak off flow while running, but not while cranking without injector pulses. A worn or damaged valve seat in an injector would cause unwanted leak-off. Hence a leak-off test can identify leaking injectors.

 

Thanks, I don't fully understand but I'll check this out. Antony

[Tdci-Peter]

2 hours ago, Antonycc said:

I don't fully understand but I'll check this out.

Yes, the injector operation is a bit more complex than most people think!

But what I wanted to say was that although the return pipes from the injectors are often called leak-off pipes, this is not a truly correct name. Even with an injector in perfect condition and no leaks, there will be a little pulse of fuel flow on each injector operation. And this flow is what is usually measured with the engine idling in a leak-off test.

If the injectors are not operating, either because the pressure is too low for the ECU to energise them, or because they are disconnected, then any flow would be the result of an internal leak. Any leaks like this could prevent the pressure from building up properly at cranking speed.

A tow start might be another option. It is not advised to try this if no fuel is getting to the HP pump to lubricate it, but since you do seem to have fuel there, it should be ok. If the higher rpm manages to get the engine started, it would narrow down the problem a bit. Though I have just re-read that it did start but then stall, on easy-start. I don't like doing this to high compression diesel engines, the resulting combustions are entirely uncontrolled, but if the easy start got it up to at least normal idle speed for a couple of seconds, then it still stalled, then it would there is either quite a major leak, or some other, possible electrical fault. A tow start could be done (with care!) for long enough to run Forscan to see if the pressure built up.

 

[Antonycc]

1 hour ago, Tdci-Peter said:

Yes, the injector operation is a bit more complex than most people think!

But what I wanted to say was that although the return pipes from the injectors are often called leak-off pipes, this is not a truly correct name. Even with an injector in perfect condition and no leaks, there will be a little pulse of fuel flow on each injector operation. And this flow is what is usually measured with the engine idling in a leak-off test.

If the injectors are not operating, either because the pressure is too low for the ECU to energise them, or because they are disconnected, then any flow would be the result of an internal leak. Any leaks like this could prevent the pressure from building up properly at cranking speed.

A tow start might be another option. It is not advised to try this if no fuel is getting to the HP pump to lubricate it, but since you do seem to have fuel there, it should be ok. If the higher rpm manages to get the engine started, it would narrow down the problem a bit. Though I have just re-read that it did start but then stall, on easy-start. I don't like doing this to high compression diesel engines, the resulting combustions are entirely uncontrolled, but if the easy start got it up to at least normal idle speed for a couple of seconds, then it still stalled, then it would there is either quite a major leak, or some other, possible electrical fault. A tow start could be done (with care!) for long enough to run Forscan to see if the pressure built up.

 

Ok, thanks for the info. I've got a few things to try out now.

Up to now, what I can confirm is:

That the injectors are not getting a pulse

Pressure before the pump replacement was 6.5bar on cranking. After pump replacement, it is now 100bar on cranking.

Fuel is getting through the pump. I know this because I have a bulb and I'm pumping it up to the pump. If I undo the injector inlets and crank, fuel pisses out of the inject pipes.

There is a tiny leak around each injector nut. It's coming from the inside of the nut and the fuel seems to create a tiny pool. I'll sort this out with PTFE later on, cowboy style.

It did start on easy start, but it sounded rough as hell. It can't run without easy start. It didn't go to normal idling speed, it just went beserk for about 5 seconds then died.

"A tow start could be done (with care!) for long enough to run Forscan to see if the pressure built up. " But it is cranking fine and the battery is fairly new. I have a second helper battery too.

 

If I was to trick the ECU into thinking that pressure was 200bar (by using a voltage divider on the FRP sensor), would the ECU then power the injectors? (As a test ofcourse).

Also, another question on a different matter; Forscan says that a dpf regen can only be performed when the engine is 65c. Which sensor is it referring to?

 

Thanks so much for your help, Antony

 

[nicam49]

On 5/15/2020 at 10:50 PM, nicam49 said:

Hi, check that your new pump is giving enough pressure:

 disconnect all the electrical drives to the injectors and also disconnect the electrical connection to IMV. This causes the IMV to be fully open. If you now crank the engine you should see >1050bar

5 hours ago, Antonycc said:

Thanks, I'll check this today.

What result did you get to the above?