1989 / 2.5 Motronic, Mondial-348 folks: Do your Check Engine lights appear when...

Yes, they do come on for a fraction of a second.

Sorry to get back at 'ya late.

Check the bulbs man. The long plastic light face panel comes right out (towards you) and you can see the bulbs. They may be missing or burnt out. Pretty easy to change out. Can gain access from behind too by pulling the speedo or tach out (again simple).

 

So sorry man. I knew some warning light came on... Its the slow down 1-4 / slow down 5-8 lights that come on when I turn the key on in my car (along with the brake check light). I went and checked just now.

 

The check engine lights DO NOT come on in 2.5 motronic based F119 engined cars (348 and Mondial t's).

The cars were both wired from the "engine forwards" for the M 2.7 ECU system, which ferrari was bench testing the last year of the F119's development (1988 and early '99). The M2.5 was never meant to go into these cars, as you can see the throttle body castings were always meant to have a double throttle position sensor built in.

The mountings for the idle air motors of the M2.5 were added to the engine block, when BOSCH was not ready for production on the 2.7 system. So Ferrari took the 2.5 system with some minor modification from the Bosch standard M 2.5 ECU to have 2 coils per bank (as opposed to distributor) and an interconenct system for 2 banks in the V8.

The modifications and the fact than the bank 5-8 ECU was the critical one (had the only TPS and tacho output) for mixture, and the 1-4 was the critical one for advance caused the first generation of the F119 to have the problems it had.

The 2.7 was merged into production later on. I have helped another Mondial t user change their M2.5 engine with a 2.7 one, and it is plug in compatible with the wiring.

I have found the wires in the bot that if grounded will light up the CELs in the dashboard. These are not connected. I have developed a small digital relay that if the O2 sensor drops below 75mV for more than 15 seconds it grounds the CEL light indicating a lean position (15 seconds prevent the triggering by sporadic drops in mixture which are normal).

Marco

 

My CEL does not come on. 89 Mondi t.