Help needed. BA rough idle issue.

[Jiminy Kriket 133]

I've looked everywhere i can think of, and everything i find i have ruled out.

 

The story so far is my dad's 03 BA XT has this issue when it is physically cold outside the engine on FIRST start up in the morning will not idle smooth, i.e. it stumbles and miss fires like it's a shot coil or a sensor issue. But it smooths out within 5 minutes of running, whether it's mobile or stationary. 

 

So, we have tried the hot water trick on the ecu, reseated all plugs onto the coils, sensors and joiners, we even went to the effort to retighten the manifold bolts. So far it has had no result.

 

The only way i've had the car reproduce the issue was to unplug the tps and plug it back in. So, we tried some freeze spray on the tps, air intake temp sender, coolant temp sender and the throttle stepper motor.

 

Once this issue sorts itself out on first start up, it's gone for the rest of the day. To the point where i can start it at 7 in the morning let it sort it's issue out it will be fine. I can even leave it for the rest of the day and try to start it at midnight on the same day and it'll idle fine right off the bat. But come the next morning and it wont idle until it sorts itself out again.

 

This is doing my head in and i havn't been able to find a fix as yet. So i come to the brains trust and see what they have to suggest.

[Outback Jack 6,352]

If you had the battery out or disconnected, it may be the same as my XG and need you to Goose the throttle to set up the Throttle Position Sensor.

I HIGHLY recommend buying an OBD2 code reader, will save you a lot of grief and chasing ya tail. If there is a fault it will show it.

I'm leaning towards MAF sensor or TPS.

Jack.

[Jiminy Kriket 133]

Should've mentioned, i've got an Autel autolink ODB scanner and it shows no codes. That threw me.

This thing kicks and bucks around like a fool and the pcm doesn't throw any errors.

 

As for "goosing" the throttle, i assume you mean moving the throttle blade to make the tangs engage properly on the tps.

Please correct me if i'm mistaken. 

 

Thanks for the pointer.

[Outback Jack 6,352]

Throttle goose not performed will come up as a code if it's that.

Make sure the scanner is OBD2 , OBD is for pre AU cars. Probably know that, but worth a mention.

 

Yeah that's strange mate. Go to a wreckers, get another ECU for same motor and gearbox combo (the ECU numbers are on side of module) and just swap em over and see. I had a problem similar on my XG which was an aircon fault that took out the Low/High idle speed section of the ECU.

For $100, that's probably ya best bet. Mine would stall and idle shit and carry on like a pig. Changed ECU..... never had a problem since.

 

Jack.

[broken-wheel 659]

turn ignition on, wait 1 min then start car, will this fix it?

[Jiminy Kriket 133]

Haven't tried that one yet broken wheel, will tell the old man to give it a go. 

 

Thanks for the advice jack. The scan tool is an odb2 unit, bought it just because the old man got this car.

I'll go have a look at the wreckers and see how much they want for an ecu.

[Stevemack 122]

Sounds like an injector is leaking down overnight perhaps?  Would dissappear  for the rest of the day, had plenty through the workshop.  If you have time, pop the plugs out first thing in the morning, then put some cardboard over the top of the holes and turn it over, if there is fuel in there you will see it on the cardboard.  Worth trying.

[Jiminy Kriket 133]

Update time. Got it solved. Number 5 ignition coil silicon boot was damaged causing it to arc from the spring inside to the cylinder head. EEK.

 

You see that little grey dot. That there is the problem.

 

Looking closer at the dot you see this...

 

Little bastard thing had me looking everywhere for the issue. New plugs and coils and it's purring like a kitten even from dead cold. Beautiful. Thanks for the suggestions as to what it may have been.

[Outback Jack 6,352]

What a lil shit of a problem.

Thanks for posting those pics, helps people looking for the same niggly problem.

Jack.

[SLO247 1,713]

Just for future reference, ECU swap in a BA isn't as simple as plugging it in like the older models.

[Jiminy Kriket 133]

Just for future reference, ECU swap in a BA isn't as simple as plugging it in like the older models.

 

Could you expand on this a bit, just in case i need to get the old man outta the shit agin.

[tpak addict 1,909]

ECU & BEM in BA+ need to be programmed for the car to start.....

Even the Radio/CD needs to be programmed

 

There are some places that can do this besides Ford

[Jiminy Kriket 133]

Thanks tpak, will have to remember that if i ever have to change his over.

[tpak addict 1,909]

Just remember tho.... Change ECU or BEM and its a tow truck to the place to get it programmed.....

[gromet88 3,042]

Cant you do this yourself by leaving the key on for 61 minutes?

[SLO247 1,713]

That's the older ones.