HP500EFI running rich?
 

New guy here! Im gonna start with a running rich question.Ive got a 2000 HP500EFI in a DCB Mach 26.Its got 100 hrs on it and the back of the transon is getting covered in black soot.The boat starts and runs perfect,but at idle you can smell the raw fuel and its making a mess on the transom.It will do it when the motor is cold and warmed up.The water temp is right at 140-150.It actually runs a tad bit richer on one side than the other.Ive done plugs,wires,and cap.I havent checked the fuel pressure yet.It has done it from day one.Could it be the mapping of the ecu?I have heard that the Hp500 is set to run rich but this is way wrong.Any ideas for me...... Johnny Rocket

Are you running Premimum gas 93+ octane? They seem to run with less soot on 87 octane. That seems to everyones mistake at first thinking 93 is better than 87 but from everyones experience this is wrong. Do a search there should be plenty of discussion on it here.

Thanks Ray,

I have tried both 87 and 91.I use 87 all the time but have not noticed any difference in the two as far as soot.Ive tried opening the hatch when starting also.I have heard of trying one step hotter plug range but havent done it yet.I'll do a search and see what comes up.Sounds like a common problem.Thanks again..

Precision Marine 504-469-7463 ask for Mark he has been at the forefront of remapping Mercury ECM's he can cure your problems and very helpfull over the phone.

Also try an extended tip plug,, like a Rapid Fire Part #1 they will help as well. Also add a K and N flame arrestor. Both those will cut it down some.

Thanks again...I tried Mark at Precision Marine but he was busy at the time.I'll call again later.Im thinking it needs the ecu redone.I just want to make sure its not in some kind of default mode before I do.Im going to get the codes ran on it as soon as I can,then get the ecu done..

I have the K and N filter on it.I will try the plugs this weekend.Wheres the best place to find them.

Believe it or not I get mine at Walmart. Definatly get a scan tool on it if you can,,, "limp" mode will do the same thing.

WallMart? ill check into that.It runs so smooth at all times right now.Will limp mode let it run this way?If its in this mode now and runs this good.Ill be excited to see normal mode thats for sure.

How about adding an MSD6M-2 to the ignition system. I did to my 454 Magnum and it cleared up the soot quite a bit.

Yes,I will be doing this soon.Did you do it yourself or not?Ive done other applications but not Mercruiser EFI stuff.Is it hard to do?

I added an MSD 6AL with the MSD wiring harness adapter and it definately made a difference. You can actually hear the difference (with dry exhaust) and the soot has been reduced noticably. Not a very hard install, it is practically plug and play.

Good Luck
Adivanman
http://www.adivanman.com

It is a real easy install, just get the right plugs from MSD and all you do is plug it into your original harness. It will definetly take you longer to screw the box to your transom than wiring it in.

Ok,does anybody have the actuall part numbers from the MSD that they used.Not so much the box but the wiring harness and plugs.I want to order the right parts from the start.Did you have to run a seperate wire straight to the battery or did you get power from the harness?

I would just call MSD to get the right part #'s. Yes, you do have to run a seperate power and ground. And don't forget to put a circuit breaker on the power wire.

MSD TECH LINE: (915) 855-7123

Has anybody had an injector stick on them.It almost seems like one injector is sticking and causing it to run richer on one side than the other.

Alright,I went out today and ran the boat.Did a plug reading and they all seem to be the same.Except one plug is dark all the way down the electrode.This plug is also on the side of the motor that is running the richest.I did a compression test and leak down,all seem to be good and really close.Actually closer than I hoped for.So now Ive got it narrowed down to a bad injector or plug wire.I didnt have time to check the wire and dont have any way of checking the injector.Does anybody have a different idea for me........?Whats the best way to check wires and injectors?Use a meter on the wire but what about the injector?

I say you bolt a Whipple on it...that'll lean it out. ;)

Atleast #2 and #7.....Whats up HH? I think I have some answers to my dark transom..

Good...I hate wiping that stuff off...:D

the injector could be dirty and dripping instead of atomizing the fuel. Cheap easy way to isolate is swap the injectors with other cyls and run it, then check the pulgs again. Run some injector cleaner through it,,, maybe youlll get lucky.

I had a bad injector on a new 454MPI It's very possible your may be bad or clogged. You could buy another and send that one out for cleaning. Then you will have a spare.

Re: Re: HP500EFI running rich?
 

I thought the same thing but the book calls for a 140 thermostat and it runs right at 140-150.

What model of MSD #6 boxes is everyone using?

We use 6al and have had no problems with them they really do seem to help
we don't add a circuit breaker to the battery wire as it needs all the amps it can get ,,be sure to run the heavy wire to the battery the hot and ground wire ,,,forsure

Thanks Bobby.....I plan on using the 6AL box.I cant see what the difference is in the marine box and the regular box.Maybe sealing compound?The performance should be the same.If the box is mounted in a dry area,the 6al should be good enough right?

yes sir their sealed in epoxy and just like you said put it in a fairly dry place and wire it right ,(heavy duty )

Are you guys running the stock coil on theHP500 or the MSD coil?

I like the e-coil MSD makes or the blaster 2 coil ,it makes a good package;) ;)

Well the MSD box is in,so are the longer reach plugs.The soot is almost unoticeable now.Looks alot better,I can live with it this way.Now to fix my leaking injector and I''l be set...

Anybody know how hard it is to get the injectors out? And who can really check them out?

Johnny be sure to xhange to an E-type msd coil !!
Also most car repair shops can clean injectors their easy to get out :D :D

Yes I will check on changing the coil.I might be jumping in to soon on the injector being bad.I think I better check the plug wire first.I guess an ohm meter should do the trick right? Any ideas on what readings I should be looking for?Im still betting the injector is not cycling right..Not closing all the way Im guessing....

GREAT WORK BOBBY!
 

Bobby- Are you finding this current loss through thermals or contacts? I wasn't aware that circuit breakers were considered even a nominal source of resistance. Just to be on the "safe" side, are there any other circuit protective devices on our boats that we should remove to prevent this current loss? Have you informed the MSD engineering staff of this systems/design flaw that you have discovered? Once again, great work Bobby!!