496 mag ho ECU
 

My ecu may have been fried by a mechanic. It went in running now doesn’t. Looking for a good working ECU to buy

Contact BUP on here. He repairs ecu's.

Thanks for putting my name on this John. Currently I am holding strong a 96 percent rate for repairs on the 555 s.

I get 1 to 3 Merc 555 s per day in for repairs and calibrations. Merc racing 1075 sci all the way down to the V 6 mpi mercruiser and all the Optimax pcm 555 on the outboard side. EVERYDAY

Past 10 days worth of ECM 555 and PCM 555 and Mercruiser Visteon Catalyst engines ECM s.
https://cimg6.ibsrv.net/gimg/www.off...838ec74431.jpg

and these within the past 10 days for repairs and calibrations
https://cimg0.ibsrv.net/gimg/www.off...d31c53c0a3.jpg

Tried contacting you BUP but says your inbox is maxed out and won’t take any new. Looking to pull ecu and get it sent off.

Sorry about that. I freed up some room currently.

or

8
one
seven

six
5
8

seven
7
two
1

THANKS

I can get you almost NIB or a NIB , these are from a certified merc dealer.

https://cimg6.ibsrv.net/gimg/www.off...d0d7b3902.jpeg

But they still have very weak internals from the being new actually weak drivers -- weak eeprom - weak capacitors and so on. Also they are very app specific. Wrong pcm / ecm there goes the engines.

BUP you can program it for the Dana exhaust as well and or is it needed to run exhaust.

Would like to take everyones money but changing to DANA exhaust really a retune is not needed. The dana exhaust are not full runner lengths compared to real headers.

Also number 2 is the stock intakes - stock throttle bodies - stock heads are still the cork in the bottle aka air flow -- keep in mind basically more air flow in requires better scavenging air flow out. You only changed exhaust and the stock 496 is not a high HP peak rpm engine anyways. At 5 K rpms there is nothing left for a jist. The heads are weak for any proven decent gains along with the cam and so on..

On the water you really are not going to see / feel anything in much of gains with a 98 percent stock engine. I like making money to live decently but I would be taking your money. A good size credit card limit and time along with testing for real tuning on the water is needed for the 496 to see great gains. The old saying is 1000 dollars for one mile per hour gain if not more $$$$ on the water.

2002 eagle230 elimanator
 

BUP……recently i was running my boat on the trailer getting ready to take it out…..out of no where it died…i went to start it and nothing…not even the fuel pump priming….i replaced the batteries seeing how one was bad and not holding a charge…..now when i turn the key it doesnt run the fuel pump prime till about 15/20 seconds later…and i verified its not getting spark either…..ive checked all the obvious things and came up empty handed…im thinking the ecm finally gave up…it was running one second and then it was dead with no spark and a delayed fuel pump prime….have you are anyone else ran into a problem like this?? Is it most likely ecm related and is it something you can fix??

not everything relates to ECM failures, ,

you need to scan it and see if you got cranking RPMs, if you don't, I would start with checking crankshaft sensor output

I already replaced the crank sensor wasnt that…and would that effect the fuel pump prime delay….i do plan on taking it to a shop if all else fails…and have them verify its the ecm….although im not getting any trouble codes

Trentdawg since you're new.
Unfortunately BUP was banned from this site. You'd have to call to get any advice from him.
His link below.

Boats Unlimited | Marine Technician Service | Inspections (boatunlimited.com)

Hi do you have a ecu to my 496 ho 2008 model?

Are you still repairing ECU's?

Ecu 866 090 t04
 

hello, I need ECU 866 090 T04, 2010. Mercruiser 496 HO. My ECU have no communication..
Need to buy used one. since l am offshore, repair is difficult. Please advise.

Martin,

Let me check the numbers on mine. Might take me a minute. It's a 2001 MY unit, so it might be a long shot. I won't have it available until we get my rebuild up and running, just in case we need to go back to the 555 :pray:.

Thanks. Brad.

Brad, are you anticipating problems with the Holley HP?

Padraig

Padraig,

Not really. The builder is working his way through the pin-outs for the HP harness (he picked up a used LS harness for the connectors and we are preserving the OEM 555 harness). He assures me he's "got this". I'm just being optimistically cautious. I'd hate to broom a perfectly good ECM, only to discover there was some insurmountable issue of non-compatibility and have to drop a massive dime on a replacement 555. My paranoia on fleek.

Thanks. Brad.

My Saris rebuild is using the HP, also. It sounds like a slick set up.

Padraig

Padraig,

On a Merc 496? That would be an awesome resource for info if needed. He's been talking with Mosetti and Eddie Young quite a bit about it. I don't know of anybody, specifically, having done it. I have no reason to doubt someone has, given the bespoke nature of the 555, I just don't know of any accounts of it. There really is no real reason one can't do it. The HP will do everything the 555 will do, including trigger the audible alarm according to your parameters; it's just a matter of the pin-outs and pin-out mapping. I just wish Holley would develop a mobile app for it like they have the Sniper system.

I have faith in the builder. I'm just not selling anything until I know we're off to the races.

Thanks. Brad.

Not a 496, mine is a 502 bored to 540.

Padraig

I know of a guy with procharged 496HOs in a 30 Daytona that has the Holley system on. He says it works good.

496 Ho
 

Hello,
I am new here, a bit confused with lot of treads.
please advice me if any solution for my problem
Thx

Martin,

Sorry. We went off on a tangent for a second….

I am in the final stages of rebuilding a Merc 496HO after a piston failure, during which we have swapped out the Motorola PCM555 for a Holley HP ECM. This was done for a number of reasons, but the 555 is still good, to my knowledge. After some discussion about the failure, I should probably have it checked to make sure the injector driver didn’t go bad, though. The issue we have here is that mine is off a model year 2001 engine and yours is a 2010. Theoretically, they should be the same, but there were apparently some changes along the way from Merc that may be of issue. I need to get to my builder and retrieve the serial numbers from my ECM and see if it would serve your needs. When I’ve got a running engine, I intend to sell my ECM. If it’s comparable with your application, we can work something out.

Thanks. Brad.

Perfect, let me know when you decide.Thx

Wanted ecm for 496 standard output ( not HO )
 

Looking for 2007 metcruiser ecm 496 standard output anyone can help?

https://cimg1.ibsrv.net/gimg/www.off...cdc9bd18e4.png
Call these folks…they just repaired my motorola 555 ecm for my mag496ho in literally less than 1 week….the injector drivers (and some crystal thingy) went bad, they had it repaired and had me back and running for around $1k……id reccommend them to anyone with mag496 ecu issues or any other electronic gremlins for that matter!!!!

do you have your original one?? I dont think that place sells them, just repairs them

I don’t have original one ( stolen )

Damn that sucks….u can try calling and see if they sell them or maybe knows of someone who does…good luck

Ok, will call them tomorrow thanks