Mercruiser 454 Magnum MPI running cool and rich
08-02-2017, 04:17 AM
#11
Registered
Thread Starter
Join Date: Aug 2017
Posts: 17
Likes: 0
Received 0 Likes
on
0 Posts
Found this info from another thread
According to this 454 mag mpi and 502 mag mpi have the same injectors.
I've been told that this two ECM (454 and 502) have the same hardware, but do they have different software? If so, is it possible to reflash it somehow? It's MEFI-1 or MEFI-2
The 805225A 1 injector (the "old" injector) fits the following models:
525 EFI 0M953620 THRU 0M956326
Mercruiser BLACK SCORPION 350 MAG MPI 0M391600 THRU 0W689999
Mercruiser BLACK SCORPION MX 6.2L MPI 0M391750 THRU 0W689999
Mercruiser 454 EFI (SKI) GEN. V GM 454 V-8 1995 0F215800 THRU 0F820099
Mercruiser 454 EFI (GEN. V) GM 454 V-8 1994-1996 0F115700 THRU 0F802349
Mercruiser 502 EFI (GEN. V) GM 502 V-8 1993-1995 0D840650 THRU 0F802599
Mercruiser 7.4LX BRAVO (MPI)(GEN. V) GM 454 V-8 1996 0F602010 THRU 0F801999
Mercruiser 7.4L MPI MIE (LH) GEN. V GM 454 V-8 1995-1996 0F563052 THRU 0F820103
Mercruiser 350 MAG. BRAVO MPI(GEN+) GM 350 V-8 1997 0K001501 AND UP
Mercruiser 454 MAG. MPI BRAVO (GEN VI) GM 454 V-8 1996-1997 0F802350 THRU 0K999999
Mercruiser 502 MAG. MPI (GEN VI) GM 502 V-8 1996 0F802600 THRU 0K999999
Mercruiser 7.4LX BRAVO (MPI)(GEN. VI) GM 454 V-8 1996-1997 0F802000 THRU 0K999999
Mercruiser 454 MAG. MPI (SKI) GEN. VI GM 454 V-8 1996-1997 0F820100 THRU 0K999999
Mercruiser 7.4L MPI MIE (LH) GEN. VI GM 454 V-8 1996-1997 0F820104 THRU 0K999999
Mercruiser 8.2L MIE MPI (LH) GEN. VI GM 502 V-8 1996-1997 0F819620 THRU 0K999999
Mercruiser 454 MAG. MPI BRAVO (GEN VI) GM 454 V-8 1998 0L010029 THRU 0L058399
Mercruiser 502 MAG. MPI BRAVO (GEN VI) GM 502 V-8 1998 0L017000 THRU 0L085432
Mercruiser 454 MAG. MPI HORIZON (GEN. VI) GM 454 V-8 0L002200 THRU 0L086049
Mercruiser 8.2L MIE MPI (GEN. VI) GM 502 V-8 0L002450 THRU 0L086012
Mercruiser Scorpion 377 0K000656 THRU 0L600314
Mercruiser Scorpion 377 Sterndrive 0L416146 THRU 0M907201
525 EFI 0M953620 THRU 0M956326
Mercruiser BLACK SCORPION 350 MAG MPI 0M391600 THRU 0W689999
Mercruiser BLACK SCORPION MX 6.2L MPI 0M391750 THRU 0W689999
Mercruiser 454 EFI (SKI) GEN. V GM 454 V-8 1995 0F215800 THRU 0F820099
Mercruiser 454 EFI (GEN. V) GM 454 V-8 1994-1996 0F115700 THRU 0F802349
Mercruiser 502 EFI (GEN. V) GM 502 V-8 1993-1995 0D840650 THRU 0F802599
Mercruiser 7.4LX BRAVO (MPI)(GEN. V) GM 454 V-8 1996 0F602010 THRU 0F801999
Mercruiser 7.4L MPI MIE (LH) GEN. V GM 454 V-8 1995-1996 0F563052 THRU 0F820103
Mercruiser 350 MAG. BRAVO MPI(GEN+) GM 350 V-8 1997 0K001501 AND UP
Mercruiser 454 MAG. MPI BRAVO (GEN VI) GM 454 V-8 1996-1997 0F802350 THRU 0K999999
Mercruiser 502 MAG. MPI (GEN VI) GM 502 V-8 1996 0F802600 THRU 0K999999
Mercruiser 7.4LX BRAVO (MPI)(GEN. VI) GM 454 V-8 1996-1997 0F802000 THRU 0K999999
Mercruiser 454 MAG. MPI (SKI) GEN. VI GM 454 V-8 1996-1997 0F820100 THRU 0K999999
Mercruiser 7.4L MPI MIE (LH) GEN. VI GM 454 V-8 1996-1997 0F820104 THRU 0K999999
Mercruiser 8.2L MIE MPI (LH) GEN. VI GM 502 V-8 1996-1997 0F819620 THRU 0K999999
Mercruiser 454 MAG. MPI BRAVO (GEN VI) GM 454 V-8 1998 0L010029 THRU 0L058399
Mercruiser 502 MAG. MPI BRAVO (GEN VI) GM 502 V-8 1998 0L017000 THRU 0L085432
Mercruiser 454 MAG. MPI HORIZON (GEN. VI) GM 454 V-8 0L002200 THRU 0L086049
Mercruiser 8.2L MIE MPI (GEN. VI) GM 502 V-8 0L002450 THRU 0L086012
Mercruiser Scorpion 377 0K000656 THRU 0L600314
Mercruiser Scorpion 377 Sterndrive 0L416146 THRU 0M907201
I've been told that this two ECM (454 and 502) have the same hardware, but do they have different software? If so, is it possible to reflash it somehow? It's MEFI-1 or MEFI-2
08-02-2017, 04:55 AM
#12
Registered
ok, so your MEFI is feeding fuel to a 502, not a 454. and without oxy sensors, it has no way to figure that out. a reflash is next on the agenda. or go get a 502...
08-02-2017, 06:15 AM
#13
Registered
Thread Starter
Join Date: Aug 2017
Posts: 17
Likes: 0
Received 0 Likes
on
0 Posts
I think i solved the temperature problem. I have aftermarket Faria Beede-gauges which use their own temperature sender (100F=450ohm). New engine came with Autometer -temperature sender which should be a standard sender (100F=1123ohm).
That's why it seems like all the components work, but temperature never gets above 130F.
Have to order new Faria temp sender from somewhere but now seems like the rich condition isn't a result of a cold engine.
I'm calling to Merc workshop this week for diagnostic tool. Maybe they could also reflash ECM if it has wrong software.
Is there any info or table for the 454/502 MEFIs, like what ECM or software should i have?
That's why it seems like all the components work, but temperature never gets above 130F.
Have to order new Faria temp sender from somewhere but now seems like the rich condition isn't a result of a cold engine.
I'm calling to Merc workshop this week for diagnostic tool. Maybe they could also reflash ECM if it has wrong software.
Is there any info or table for the 454/502 MEFIs, like what ECM or software should i have?
Last edited by 715517; 08-02-2017 at 06:17 AM.
08-02-2017, 07:23 AM
#15
Registered
Thread Starter
Join Date: Aug 2017
Posts: 17
Likes: 0
Received 0 Likes
on
0 Posts
Yes, ECM has its own temperature sender, which also has been replaced. Also the wiring harness is measured and it's OK.
But i thought earlier that engine is running cold because temp gauge was always below 130F and that caused rich condition at idle. I tested the gauge and harness by grounding the wire, and measured temp sender and they all worked so i believed that engine was really running cold. Now it seems like i have a wrong temp sender for my aftermarket gauge.
So it seems like the rich idle isn't a temperature problem.
But i thought earlier that engine is running cold because temp gauge was always below 130F and that caused rich condition at idle. I tested the gauge and harness by grounding the wire, and measured temp sender and they all worked so i believed that engine was really running cold. Now it seems like i have a wrong temp sender for my aftermarket gauge.
So it seems like the rich idle isn't a temperature problem.
08-02-2017, 08:46 AM
#16
Platinum Member
Platinum Member
iTrader: (1)
You answered the question of your problem in first paragraph.
Motor WAS a mefi 3, if thats correct it should have maggetti marrelli fiat mini injectors, they are quite short and small. They also flow 46 lbs per hr from factory. You say original mefi3 ecu and harness were swapped for a mefi 1. The mefi1 motors used a larger bodied injector that flowed LESS fuel than the mefi3 injectors. I have flowed and cleaned quite a few sets of maggeti marelli injectors and a few sets of early mefi injectors, they definately do NOT flow same.
So a mefi1 ecu even IF its for same motor is set to open injectors longer than mefi3 as they flow less. You may have other problems, the ect chart in programming adds fuel until 40 celcius and i think blends it between 60 c so if motor doesnt hit certain temperature it will blend a little fuel in but at 130 if thats correct its not s ton.
The injectors are 10 or 15% bigger though so theres alot of your extra furl if it hasnt been reprogrammed or "scaled " for injector size, Smitty
Motor WAS a mefi 3, if thats correct it should have maggetti marrelli fiat mini injectors, they are quite short and small. They also flow 46 lbs per hr from factory. You say original mefi3 ecu and harness were swapped for a mefi 1. The mefi1 motors used a larger bodied injector that flowed LESS fuel than the mefi3 injectors. I have flowed and cleaned quite a few sets of maggeti marelli injectors and a few sets of early mefi injectors, they definately do NOT flow same.
So a mefi1 ecu even IF its for same motor is set to open injectors longer than mefi3 as they flow less. You may have other problems, the ect chart in programming adds fuel until 40 celcius and i think blends it between 60 c so if motor doesnt hit certain temperature it will blend a little fuel in but at 130 if thats correct its not s ton.
The injectors are 10 or 15% bigger though so theres alot of your extra furl if it hasnt been reprogrammed or "scaled " for injector size, Smitty
08-02-2017, 09:01 AM
#17
Platinum Member
Platinum Member
iTrader: (1)
Re-reading your post i slso see its a ecu with 502 programming on top of being programmed for smaller injectors being used on a 454, although i have tuned and seen quite a few 502 files i havent seen any stock 454 files but like mentioned, tgat too will have more fuel. Can you take a picture of #7 fuel injector and post it, its right in front of distributor and is easiest one to get to , i will be able to help you more if we know for a fact you actually have mefi3/ mini injectors, Smitty
08-02-2017, 09:20 AM
#19
Platinum Member
Platinum Member
iTrader: (1)
- I just turned on my laptop and flipped back and forth between a mefi1 stock 502 file snd mefi3. There are areas where a mefi1 502 program is richer than a mefi3 but mefi1 is a crude file w low resolution and weird multipliers so really hard to compare. I will say this though, the ect table is pile of **** too. Adds 18% fuel from 40 celcius down, adds no fuel at 60 celcius, at 50 celcius or anywhere in beyween keep in mind it balances between both points, ie, at 50c would ad 9% fuel. I have pictures i just took but ill be damned if this site changed their photo crap again so i cant post them, Smitty
08-02-2017, 09:26 AM
#20
Platinum Member
Platinum Member
iTrader: (1)
Hokey ect file, stock mefi1 502, if your anywhere near 40c your getting a extra 18% more fuel EVERYWHERE! I think you have 3 issues, might be touching ect table and gaining fuel, 502 tune on 454=more fuel, mefi1 ecu on.mefi3 higher flowing injectors =more fuel
