ECM identification (can i have de right ECM calibration checksum) Hitting rev limiter

[Steph_RS]

First:

Boat: Baja H2x 2001 (4 people + 1/2 tank) temp 7degree celcius
Drive: Bravo 1 , 1.50 gear ratio
Prop: Mirage plus 23p
Top speed on the rev-limiter (66-67Mph)
Engine is a 454 Magnum MPI 2000 (385hp)
RPM range: 4600-5000
Rev limiter (supose to be) : 5100-5150rpm


Last week end i have tested my new boat on the river, I try a WOT pass and a 4700-4800 i hit the rev limiter. Is below 5100 alot, ok it is possible my RPM Gauge is off but 300-400 rpm it seem to be big.

I have a Mefi 3 Delphi 1623699 ECM , serial # 866999KA0005247 , Calibration Checksum: CB5A

Do you thing this is the right calibration (454 mag MPI)

Next time i'l try an other RPM gauge.

Thank you for your help

 

[Pete104]

Re: ECM identification (can i have de right ECM calibration checksum) Hitting rev lim

Let us know how goes with a "Shop TACH"!

 

[achris]

Re: ECM identification (can i have de right ECM calibration checksum) Hitting rev lim

Friend of mine's tach is seriously out. Reads 950 when the engine's doing 625. Don't trust the dash tacho, it's a guide and that's all... Get a digital shop tacho, or check the reading on the dash tacho with the tacho signal simulator on the diagnostic software....

 

[Bondo]

Re: ECM identification (can i have de right ECM calibration checksum) Hitting rev lim

Last week end i have tested my new boat on the river, I try a WOT pass and a 4700-4800 i hit the rev limiter.

Ayuh,.... Are ya Sure you hit the rev-limiter,,..?? or is that yer Rpms at Wot, because of the prop, 'n hp,..??

 

[Steph_RS]

Re: ECM identification (can i have de right ECM calibration checksum) Hitting rev lim

Ayuh,.... Are ya Sure you hit the rev-limiter,,..?? or is that yer Rpms at Wot, because of the prop, 'n hp,..??

Yes i'm prety sure that is the rev-limiter, when i'm hiting 4800 rpm the rpm down and up again (between 4700-4800rpm aproximetly) again and again, it fell like fuel cut or/and fire missing very constently a that rpm.

That's why i'm asking if i have the right ECM/Prog. beacause the 7.4 mpi (310 hp) model have Rev-limiter at 4600rpm with operating RPM of 4200-4600 and the 7.4 Mag MPI (385hp) model like mine supose to have the rev-limiter at 5100-5150 rpm with operating RPM of 4600-5000 rpm.

Any one have a 454 mag MPi 2000 and above and can check ECU # and the 4 number/letter on the top of them ?


Thank you very much for your help that is very apreciated

 

[achris]

Re: ECM identification (can i have de right ECM calibration checksum) Hitting rev lim

Again, check it with a KNOW ACCURATE tacho, like a digital advance timing light....
300 revs at 5100 is less than 6% and that's easily within the spec of a dash tacho....

 

[Steph_RS]

Re: ECM identification (can i have de right ECM calibration checksum) Hitting rev lim

Ok i will try next time.

But you realy think my boat was able tu push at 5100 rpm with mirage plus 23p prop with 1.5 gear ratio with 4 people and 1/2 tank? Maybe but if i try a mirage plus 25p i'm sure he can going over 70mph. It sound to fast for this hull with that power i think.

 

[Steve91T]

Re: ECM identification (can i have de right ECM calibration checksum) Hitting rev lim

Ok i will try next time.

But you realy think my boat was able tu push at 5100 rpm with mirage plus 23p prop with 1.5 gear ratio with 4 people and 1/2 tank? Maybe but if i try a mirage plus 25p i sure he can going over 70mph. I sound to fast for this hull with that power i think.

Speeds per GPS, right?

 

[Steph_RS]

Re: ECM identification (can i have de right ECM calibration checksum) Hitting rev lim

Speeds per GPS, right?

Yes