Fixing the BA PCM/ECU 'wont start cold' issue

[k31th]

alright, here's the BF ones (I6 engine, obviously, in two parts): 

[xr6tForMe]

On 15/06/2025 at 2:40 AM, ValleyKing said:

I feel I have enough electronics skills to fix a cracked connection on a circuit board but tracking it down without a circuit diagram might be tricky.

I would be interested in seeing how a DIY repair works out for you.  Given the age of these cars now, I think I might be tackling this at some point too.

 

It would be great if you could document your attempt at fixing this.

[ValleyKing]

Will do. The plan is to get a replacement, clone the original, and put that in before opening up the old one. Found some pics on google of cut open ECUs and there is a good bit of room inside to safely cut it open without damaging the board. From an initial look I think the problem stems from the side mounting screws holding the board too stiff, so when it gets cold the board doesn't shrink with the components. There are mid mounting bolts holding the connectors to the board which should be sufficient to hold the board in place.

 

I think removing the side bolts and adding some dabs of silicone to make sure it doesn't vibrate should prevent the problem from recurring, but at this point mine probably has some cracked connections from the shrink/expand cycle that need resoldering. The other option if the circuit layout allows would be to drill out the holes in the board slightly to let it flex at the bolt point, then just loosening the bolts very slightly

[xr6tForMe]

Looks like you have a good idea of where you are going with this.

I also sent you a message that I think might be helpful.

[RainingPistons]

if its a XR8 then sadly the only way to fix these is by paying Injections 2 Grand to fix the ECU as it cant be cloned onto a NA ECU even if its a 4 SPD NA ECU as ive tried and been researching this for about 4 years and the only option is paying 2 grand to get it repaired if the repair is possible majority of the ECU's are not repairable but ones that are ive read that some can work for a couple years 2/3 years max and conk out again randomly and some can only last 12 months even less ive heard of some even failing 3 days to a week later and the cycle continues as it was a notorious issue with the XR8 ECU's sadly and it used to be 1 grand now recently put upto 2 grand and even if you find someone wrecking one with a ECU that might be damaged already and or even conk out the same its not why or how it happens its when it happens as its unavoidable with these XR8 ECU's which is why so many people are just scraping these XR8s because its that difficult to get a hold of these ECU's and even then its just a matter of time untill they conk out unfortunately ford really should of done some sort of Recall on these but never did and now its to late the prices of the ECU's are just going to go up in price and the more and more that conk out and cant be repaired eventually there will be no more to buy which is the real downfall of the XR8s that's why people sell them because one theres a stuffed ECU that's basically the end of the car because its nothing but ECU issues from then on so far the longest ive personally known of a XR8 repaired ECU to last was just shy of 2 years which is ridiculous when you think about all the money youll have to constantly spend on ECU's and the price just keeps rising for these ECU's  if its a Barra 6 Cylinder then the 6 cylinder ecus can be reflashed but the boss 260  xr8 ones unfortunately alot of money is needed and also just the stress of thinking whens it going to conk out hopefully its not going to leave me standed today

[k31th]

well, the market will stabilize... the XR8 ECU can be replaced with a haltech plug-in, for example. There'll always be a market for ECU's if the vehicles are still around.

[RainingPistons]

Yea that haltec plug in is 5k though, repairs for ECU 2k from injections so it'd quite costly especially since the repairs I've heard longest was like 3 years and the quickest failure was 3 months but yea it can be worked around if you do get the haltec setup but that is 5k 4k cheapest 

[k31th]

 

Of course you can do that sort of repair for $2k, but how many times is it worth it compared to an aftermarket ECU etc? as soon as the repair gets above $2.5k I think it's not worth it and I'd just go a haltech, of course, but that's just me.

[RainingPistons]

Also it was 1k just a few months ago to repair the ecus from injections now its gone upto 2k sadly so it'll keep rising and the ecus will keep rising in price so it's the best option to spend the 5k and get the haltec but depends on if you've warrent the 5k spend for the car but it's a option 

 

After my mate got 2 repaired in 2 years he thought to himself wait why did I just do 2 repairs when I could of got a haltec he did end up getting the haltec for 4 and a half grand so hasn't had any issues so far it's been 7 months 

[ValleyKing]

Yeah $4.5k for a Haltech ECU is extortionate if you just want a basic ecu and don't need all the high performance tuning software options it comes with, especially when your car has a market value of $6K. The job of an ecu can be done by an Arduino board which costs less than $50. There is actually an open source project called "Speeduino" which does exactly that, but so far I have only found the necessary code for a few European cars, and I'm not kitted out to extract and assemble the necessary code to run a BA.

 

Its a shame no-one with the appropriate skills has made a basic replacement ecu, because it seems like there's a market for it and if it was under $1K I'd go straight for it. But $4.5k to fix a 20 year old car is a bit harsh on my budget