2.9 BOB Cosworth 24v ECU / MAF

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80s-new-man
Posts: 161
Joined: Tue May 21, 2019 11:21 am
Car(s): Ford Capri 2.9 Cosworth Dec 1984, reg. Feb 1985
Ford Sierra XR4x4 2.9 1992
Jaguar XJR SC 4.0 2001
Location: Suffolk

2.9 BOB Cosworth 24v ECU / MAF

Post by 80s-new-man »

Hi there - has anyone got, or experienced having a Capri with such heart transplant? Mines running a 1995 Scorpio Cosworth 24v 2.9. Sometimes she runs really fast at start up or just randomly whether hot or cold - 1500 or 2000 revs. A few times she’ll stall at cold Tickover.
I’m thinking to start with the MAF. I cleaned it but no joy.
I noticed the part number is 91GB-12B579-AA but looking up the part I get 94BB12B579CA for the Scorpio.
Now I have no idea what ecu she’s got but I heard something about that the ECU from the earlier Granada Scorpio is normally fitted.
Is that the case? Would no way the later Scorpio ecu be fitted for some reason?
Alternatively I may be barking up the wrong tree, should I be checking ICSV or air temp sensor diode as well ?
Cheers
Cheers
:cheers:
Capri 2.9i Special 1984 Cossie 24v BOB heart transplant
Sierra XR4x4 2.9i 1992
Jaguar XJR 4.0 SC 2001
Jaguar F-Type 3.0S sc 380
B@fink
Posts: 72
Joined: Thu Mar 18, 2021 4:43 pm
Car(s): Fiat Tipo diseasel (daily driver)
Audi A8 luxobarge (high days, holidays and general waft)
Ford Capri 1.6 Laser (former daily driver, stored 15 years, rebuilt in lockdown, done, but in dire need of paint)

Re: 2.9 BOB Cosworth 24v ECU / MAF

Post by B@fink »

Have you confirmed Coolant temperature sensor values? They play a part in start up enrichment, effectively telling the ECU it needs “choke”. You should be able to find values for it’s output hot/cold to see if it’s responding correctly. Then check the rest of the items you’ve listed, they can all stick an oar in as well :xd:
80s-new-man
Posts: 161
Joined: Tue May 21, 2019 11:21 am
Car(s): Ford Capri 2.9 Cosworth Dec 1984, reg. Feb 1985
Ford Sierra XR4x4 2.9 1992
Jaguar XJR SC 4.0 2001
Location: Suffolk

Re: 2.9 BOB Cosworth 24v ECU / MAF

Post by 80s-new-man »

Nope I didn’t.. how is that done? I do notice she runs a little colder than I’d have thought.
Cheers
:cheers:
Capri 2.9i Special 1984 Cossie 24v BOB heart transplant
Sierra XR4x4 2.9i 1992
Jaguar XJR 4.0 SC 2001
Jaguar F-Type 3.0S sc 380
B@fink
Posts: 72
Joined: Thu Mar 18, 2021 4:43 pm
Car(s): Fiat Tipo diseasel (daily driver)
Audi A8 luxobarge (high days, holidays and general waft)
Ford Capri 1.6 Laser (former daily driver, stored 15 years, rebuilt in lockdown, done, but in dire need of paint)

Re: 2.9 BOB Cosworth 24v ECU / MAF

Post by B@fink »

The Haynes manual for models with that engine should list a resistance value for the coolant sensor both hot and cold. If it’s out of tolerance the ECU (basic as it is on these engines) will substitute values or just respond incorrectly. As there’s very little plug in support (EOBD) for older cars I’d recommend the old Haynes manual on diagnostics which listed sensor types and diagnostic tests to help you check expected values of your system’s components. May help you find the fault.
80s-new-man
Posts: 161
Joined: Tue May 21, 2019 11:21 am
Car(s): Ford Capri 2.9 Cosworth Dec 1984, reg. Feb 1985
Ford Sierra XR4x4 2.9 1992
Jaguar XJR SC 4.0 2001
Location: Suffolk

Re: 2.9 BOB Cosworth 24v ECU / MAF

Post by 80s-new-man »

Appreciate that! Cheers
Cheers
:cheers:
Capri 2.9i Special 1984 Cossie 24v BOB heart transplant
Sierra XR4x4 2.9i 1992
Jaguar XJR 4.0 SC 2001
Jaguar F-Type 3.0S sc 380
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