Unleaded XF EFi - won't start

[Panko 2,480]

Hi guys, 

 

It's hard to believe that after owning my Ghia wagon for 14 years, after my dad owning it since 1992, i am here stuck with a car that refuses to start. 

 

I believe its 100% self inflicted but am after advice. 

 

During 2020, I experimented with converting the car to run an EL ECU with J3. I had some success with it, but in recent months its been a total pig, and not reliable. 

 

Ive been trying to convert it back to the original XF ECU. Ive swapped everything back to how it should be for XF. made sure the ECU pinout is back to how it should be, plugged the vane AFM back in. as far as im aware, everything as it should be to run on the XF ECU as per factory standard. 

 

The issue is, the car will start and run for about 10 seconds, very richly, then die, and refuse to start again. after sitting for half hour or so, it will start, blow lots of black smoke, run like a pig, clear itself, run fine for less than a minute then die, and the process starts all over again. 

 

I don't know what ive missed, and I miss being able to just turn the key and drive it. 

 

Before i attempted the EL ECU conversion, it was always reliable, and ive fucked something up, and my poor car is suffering. 

Any ideas would be greatly appreciated. 

[gerg 10,871]

Do you think it might be a crook coolant temp sensor which is giving you a bum-steer, as in it wasn't the ECU after all?

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[Panko 2,480]

10 minutes ago, gerg said:

Do you think it might be a crook coolant temp sensor which is giving you a bum-steer, as in it wasn't the ECU after all?

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it would explain running rich when it does decide to start, but would it allow it to start and run for 10 seconds then conk out? 

[XCeed 205]

Hi Panko,

 

Do you have a way to log the data from your sensors, like a Moates Quarterhorse can do? They're pricey at around AUD $500 but it will plug into both your XF EEC IV and EL EEC V. Hook it up to a laptop and (hopefully after forking out $500) find out what's going on. Then tune the crossy to your liking.

[gerg 10,871]

it would explain running rich when it does decide to start, but would it allow it to start and run for 10 seconds then conk out? 

Actually it shouldn't run any richer than it does at cold startup. Can you get it to fire ok on aerostart (pull fuel pump fuse or relay)?

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[Panko 2,480]

7 minutes ago, gerg said:

Actually it shouldn't run any richer than it does at cold startup. Can you get it to fire ok on aerostart (pull fuel pump fuse or relay)?

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I haven’t tried that

[Panko 2,480]

9 minutes ago, XCeed said:

Hi Panko,

 

Do you have a way to log the data from your sensors, like a Moates Quarterhorse can do? They're pricey at around AUD $500 but it will plug into both your XF EEC IV and EL EEC V. Hook it up to a laptop and (hopefully after forking out $500) find out what's going on. Then tune the crossy to your liking.

No I don’t 

 

i was running a J3, but no interface to read data. 
 

I have a Haltech Elite ECU to go in the car eventually when the new crossflow goes in. 
but for the time being was just trying to go back to old faithful stock xf ecu so i could drive the car again without problems 

[XCeed 205]

Well, if you've got a Haltech Elite on standby to run the new crossy (and turbo I think I've read), no point in getting a Quarterhorse.

 

I suppose if I were you I'd be getting out the multimeter and breaking into every sensor output signal and making sure the output voltage/resistance/whatever, is to be expected at cold start. If the signal is wrong, investigate further.

 

I approach troubleshooting like a lawyer approaches a person on the stand. Never ask a question that you don't already know the answer. Know what the sensor should output on cold start, and get the response. If you don't get the response you know you should, investigate further.

[deankxf 20,262]

any chance you've still got the IAC plumbed backwards? 

 

My EB XR6 back in the day a neighbour bumped a vac hose off somewhere and it bellowed so much black smoke i thought it was stuffed.. stuck hose on .. fixed. 

 

[Panko 2,480]

10 minutes ago, deankdx said:

any chance you've still got the IAC plumbed backwards? 

 

My EB XR6 back in the day a neighbour bumped a vac hose off somewhere and it bellowed so much black smoke i thought it was stuffed.. stuck hose on .. fixed. 

 

On the xf cant get the ISC valve backwards because the pipes are moulded 

 

yeah im thinking its a vacuum leak but don’t know where from 

[deankxf 20,262]

1 minute ago, Panko said:

On the xf cant get the ISC valve backwards because the pipes are moulded 

 

yeah im thinking its a vacuum leak but don’t know where from 

dipstick even used to be an issue on those things, oil cap, that other breather thing on the rocker cover to the throttle body.. 

wonder if it could be something that's been there the whole time causing issues with the E series ECU, like could it be a manifold gasket or the runners and the E series was better at masking it

[Panko 2,480]

9 hours ago, deankdx said:

dipstick even used to be an issue on those things, oil cap, that other breather thing on the rocker cover to the throttle body.. 

wonder if it could be something that's been there the whole time causing issues with the E series ECU, like could it be a manifold gasket or the runners and the E series was better at masking it

not the dipstick. 
maybe oil cap, it still locks down tight. 
 

I did go along and torque all the intake manifold bolts to make they were tight. 
 

im thinking maybe either the ISC valve is doing something funky, maybe solenoid is wigging out, or the intake plenum is leaking somewhere, which im sure id be able to hear. 
 

i swapped out the plenum when i did this conversion, because i had to add an IAT sensor and I didn’t want to drill my original. 
I stuffed up the first one and had to black it, so maybe the blacking plug has started leaking 

[deankxf 20,262]

might need to get a smoke machine tester .. 

 

i haven't watched this, it's the first one i could find on google

 

 

[Mr Polson 10,214]

Try unplugging the ISC and see if it runs? From memory, they should still run without it plugged in because I think you unplug it to set the base idle.
Pretty sure they should also run without the MAF plugged in (but won't rev or drive).

[Panko 2,480]

Ok guys, bit of an update, still open to ideas. 
 

it appears to be a vacuum leak. I have crosschecked my wiring with a ford service manual, everything is as it should be. 
 

i managed to get the car started today, and was able to keep it alive. 
 

so it runs very rough, and very rich. Struggles to idle and is hunting. 
 

If i rev it up, it hangs for a bit then struggles to settles. 
 

i pulled the dipstick out a tad to see if it reacts to that and it does, it tried to recover but stalled. Then flooded and was unable to start it again. 
 

Ive removed the egr and jerry rigged a blank for it, because ive had one fail on me years ago causing similar. 
I have some good vacuum hose that im going to use to completely loop the vacuum circuit back on itself to see if that is the issue (from intake manifold) 

 

has anyone had a vacuum tank split? Because I can not find any other obvious vacuum leaks  

 

open to ideas. 

[Banno 479]

Check fuel regulator. Had mine years ago fail and was pumping extra fuel and made it run rich and rough etc. Pulled the Vacuum line off and was damp with petrol and smell. Took fuel reg off and petrol leaked out of the vacuum end of reg.


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[Panko 2,480]

Ok. Had it running again this morning, everything still pointing towards a vacuum leak. 

i have now blocked everything that is vacuum related, including brake booster, and it refuses to start again. 
Basically it floods when it dies then i can’t seem to get it to go again. 
 

im now wondering maybe still something electrical.

Coil?

ignition module is only 12 months old

Fitted new plugs last night

Could a failing TPS do this? 
i have tried nearly everything and can’t seem to get it 

[Outback Jack 6,352]

Do you have the vac lines right way around. One off throttle body goes to air cleaner, one on intake goes to pcv valve on motor.

Just worth a check, and did you torque the manifold up?

Seems to be what happens when the motor is reading super lean on the O2 sensor, so ecu Richens it right up to compensate.

Check all your loom connections too.

 

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[Panko 2,480]

15 minutes ago, Outback Jack said:

Do you have the vac lines right way around. One off throttle body goes to air cleaner, one on intake goes to pcv valve on motor.

Just worth a check, and did you torque the manifold up?

Seems to be what happens when the motor is reading super lean on the O2 sensor, so ecu Richens it right up to compensate.

Check all your loom connections too.

 

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On the xf there is no vac line to air cleaner. There is one from TB to rocker cover, pre butterfly, there is the PCV, post butterfly, then ISC valve pipes pre and post butterfly. All are correct, because they are alp moulded hoses and can’t be put on incorrectly. 
 

Yeah i know what you mean, but ive gone back to XF ECU which doesn’t use an oxygen sensor. 

[Panko 2,480]

Bit of an update. 
 

After trying everything i can think of, including bypassing all vacuum ancillaries, including booster, changing ISC solenoids, trying different timing settings, cleaning dizzy cap and rotor button, you name it i have tried. 
I decided to swap the ECU for the J3 chipped EL unit that i removed from the car, but left ALL XF sensors in place. 
- AFM vane meter

- ISC valve

 

There is no MAP sensor, IAT sensor or o2 sensor, yet the car started straight away on the EL ecu. 
it ran like a pig, but it ran, and was able to reliably start it again and again. 
 

Weirdly, the engine was NOT affected by vacuum leaks with the EL computer, or affected by unplugging the AFM. 

so the issue is definitely electrical related, but what that issue is, I have no idea.  

[Outback Jack 6,352]

Is the isc wired around the right way? I seem to remember you changed it at some point or changed the isc. I reckon that or just double check your pin outs.

 

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[Panko 2,480]

27 minutes ago, Outback Jack said:

Is the isc wired around the right way? I seem to remember you changed it at some point or changed the isc. I reckon that or just double check your pin outs.

 

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Yeah it is. 
 

what. I did with that was i remote mounted an E series ISC valve. Put it back to stock XF now 

[XCeed 205]

What's the condition of your loom? 35 years old, changing this and that, you might have a broken wire. Maybe break out the multi-meter and check for continuity on each and every wire involved in engine management. From one end to the other of each wire, make sure it's a dead short.

[Panko 2,480]

14 minutes ago, XCeed said:

What's the condition of your loom? 35 years old, changing this and that, you might have a broken wire. Maybe break out the multi-meter and check for continuity on each and every wire involved in engine management. From one end to the other of each wire, make sure it's a dead short.

Yeah thats my next test. But i need a second set of hands for that. 

[xd4.1efisc 34]

Did you use the correct wiring diagram when you changed the pins back.

There is Pre Adr 37 (leaded) and Post Adr 37 (unleaded).

The pin locations for the VAF and some other stuff is different.