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        General >> Give/Need advice to/from others >> PCM replacement
        
(Message started by: jonnycab on May 31^st, 2007, 1:11am)

Title: PCM replacement
Post by jonnycab on May 31^st, 2007, 1:11am

I know this has been covered recently, but some were not in agreement on whether or not the PCM can be replaced without reprogramming.

On earlier models it may have been possible to swap the PCM for another & have the car run as normal.

But I seem to remember reading on the main site that the later models & facelift had the PATS integrated into the PCM, so replacing the PCM & expecting the car to start was impossible without reprogramming the PATS.

This would seem the case, as I have tried it...with an almost brand new 2.3 PCM....car turned over, but would not start.

Why do I want to replace the PCM ?....simple really.........IT'S STILL PINKING >:(

After all the sensors & parts that have been replaced/tested (no air leaks either), & I've still got this really annoying intermittent pinking ???....it comes & goes & there is no regular pattern to it ???

So I still think, unless otherwise advised of some other reason why it should pink intermittently, that the PCM is at fault.

So, the question is....does the new PCM have to be reprogrammed by Ford, or can someone on here (localish) do it for a few drinks ;)

If Ford only...then how much do they charge ?....couple of hundred ? ::)

Title: Re: PCM replacement
Post by TiberiuS on May 31^st, 2007, 1:21am

Jonny, what's your plugs like? I have a guide to reading sparkplugs if you need it ;)

When I had my Scorpio, I understood that they were all the same ECU but with different versions of the software for different models, so they might or migght not work, depending on model/configuration. Got mine reprogrammed as a sweetner when I had the autobox fitted, I believe they said the cost for programming alone was around £150 :-/

Regards, Bruce.

Title: Re: PCM replacement
Post by jonnycab on May 31^st, 2007, 1:37am

Plugs have 5000 miles on them & they're fine :)

I changed them because of the pinking, but to be honest, the car has pinked intermittently since the day I bought it....or soon after :-/

Bruce mate....I've got a good spark plug guide & my plugs don't seem to point toward a bad engine....I average 24mpg around town & 30+ on the motorway ;)

£150 for a reprogram....it's still daylight robbery, but I may give them a ring :)

The main reason I'm still thinking the PCM, is because pinking is only usually caused by incorrrect timing or incorrect fuel grade.......most petrol is pretty standard & I only tend to stick to BP, ESSO & Shell, so I'm going for the timing theory now ;)

So after replacing practically every sensor that connects to the PCM, then the only logical explanation in my mind is 'the silver box' :)

Title: Re: PCM replacement
Post by Spannerdemon on May 31^st, 2007, 8:45am

This firm will test your ECU (PCM) for a small fee. Ring them for a price.

HERE (http://www.the-ecu-doctor.co.uk/)

They have an unrivalled reputation right through the motor trade, and if there's no fault on it, they will tell you, and if there is, they'll fix it. Cheaper than the alternatives. ;)

Title: Re: PCM replacement
Post by jonnycab on May 31^st, 2007, 1:43pm

Cheers Keith ;)

Title: Re: PCM replacement
Post by TiberiuS on May 31^st, 2007, 6:22pm

I found the job sheet from when they quoted for the job in October 2005 and I asked about reprogramming - £110.52 incl VAT. It didn't make much difference to the car TBH, only changed the feel of it when pulling off from rest and made it idle slightly smoother...apart from that it drove the same as before.

Title: Re: PCM replacement
Post by pedropedro on May 31^st, 2007, 8:39pm

I've been following your posts over the months re pinking and can sense the grief its causing. I've had same issue on mine ..conclusion from x2 good engineers ..timing ...chain has been put on half a cog out. Maybe yours had head gasket changed like mine....mine was perfect before head job..then it pinked.It wasnt the skimming producing higher compression...it almost goes with premium fuel ..runs ok for a few days then back it comes..drives me nuts!

most folk assume if chain is on wrong valves will hit pistons etc but apparently its really difficult to get back perfectly and quite easy for it to be a a tad out

hope you find a fix...john

Title: Re: PCM replacement
Post by jonnycab on Jun 1^st, 2007, 2:05am

Now that's a thought John....would the timing chain being half a cog out only cause intermittent pinking, or would it do it all the time ?....I wonder :-/

The head gasket hasn't been replaced....but it did have a complete new engine 60K miles ago (before I bought it) :)

For the moment though I'm gonna find someone local who can test the PCM :)

Title: Re: PCM replacement
Post by pedropedro on Jun 1^st, 2007, 8:51am

the answer is yes ..the ecu makes adjustments and can just cope sometimes......if you scan does it come up "lean" mine does all the time..thats the ECU trying to make adjustment

Mine runs smooth for a week or so then the pinking starts maybe a slightly lower octane fuel trips ecu past a point where it cant cope...clue is to scan and see if its running lean all the time.

john

Title: Re: PCM replacement
Post by jonnycab on Jun 2^nd, 2007, 3:55am

The only scans I can do are with my little Autel handheld, but it never brings up any fault codes :)

Regarding the timing chain being a tad out....the new engine has done 60K, when I bought the car last year the new engine had done 30K.

So I doubt whether the head gasket would have been replaced in the first 30K, in fact I'm certain, as the new engine is painted with a kind of brown hammerite (new 2.3 engines are) & the paint is not broken around the rocker cover, so it obviously hasn't been taken apart ;)

If the timing chain is out, then it must have come out of the factory like it & being that those Germans are an efficient bunch, then I don't think that they would make that mistake :-/

Thanks John for the advice, but for the moment, I'm going to discount the timing chain theory in my case :)

Title: Re: PCM replacement
Post by Kjetil S on Jun 3^rd, 2007, 12:07pm

I don't remember (and being to lazy to check) if you've changed the HO2S-sensors. I just replaced mine, and it made the engine a lot quieter.

Title: Re: PCM replacement
Post by jonnycab on Jun 3^rd, 2007, 12:26pm

Yep....new HO2 sensor a few weeks ago :)