fordf350

This has probably been a topic in the past but I haven't found to much on it. I purchased a 2000 Fountain with 500 EFIs with just over 500 hrs. So I knew they were due rebuild and they have been rebuilt and are back in the boat. Well I sent my injectors to someone that I found on one of the other boating forums to be tested and they are bad. Real bad. He sent me countless videos of them failing or barely passing with the exception of one. I have no reason what so ever to not believe the guy. But he is recommending injectors by Bosch and I don't know enough about injectors. Anyone have experience with them rather it is good or bad? Or is there something else I should look at? I spent a lot of knuckle busting and greenbacks to go cheap here so $$$ is not a concern I just want the best for the boat. And no I am not going normal aspiration, Maybe on the next boat. Thanks in advance.

BUP

iTrader: (9)

Mark this would this be me. As I have your injectors. The injectors have to matched flow volumes and dead time events of the injectors inwhich very important for replacement. The company I use is an OEM Bosch company sales and distributor plus has better testing capabilities than I. Like in the 1000s upon 1000 s dollar ranges.

I understand not knowing me but I am sure if you asked up here about my screen name that I will have good feedback and I am totally qualified in the marine field.

Also to report for the 500 EFI these are Rochestor Multec injectors and if you ever did a search on Multec injectors problems you will see they are not a good injectors to have after they have been in use for years. The internal coils become weaken and can perform badly.

In this case of the injectors I have in my hands, (OP) --- one injectors shuts completely down at 53 psi and another one shuts down at 59 psi another one shuts down at 60 psi. One runs well as I can run it past 80 psi fluid pressure. The flow volumes are uneven and at 650 rpms - 3 Ms - 43 psi 2 injectors are way off flow volumes - I only tested 6 of the 16 because MULTECS are junk as I know this already MORE TIMES THAN NOT. I did not want to rack up his bill and then tell him sorry you need new injectors on top of my charges,

I can clean up your injectors and charge you but I do not want my name on them for any liability zero.. The reason I am posting here if that was to take place.

If you want to verify what I am saying here or as I told you . plus seek out true experts in the field of fuel injectors like Injector Dynamics or hard core tuners. I promise I am giving solid advice here. Also for me not to have any liability of these injectors, I can send them back to you for a small charge for my time and testing 6 injectors only plus for vids and the pics I took to send to you,

Granted I am not nor never said I am THEE Expert about all of this but I sure follow and have the phone #;s of the people that are. Had to post this as I totally understand your concerns 100 %. No doubt about that. Thank you for at least selecting me to even test your injectors no matter of your decisions.

BUP

iTrader: (9)

I knew about this vid 9 years ago and the Merc racing 500 EFI uses the Multecs I have been doing marine fuel injector testing now for 8 years. I study what I could at those timeframes 8 years ago before getting into the injector flow bench Testing end.

GM / Rochestor Multecs fuel injectors - the ones in my hands are not as bad as these in the vids by no means from the 6 only I tested (there is no reason to test anymore nor rack up a bill) but these injectors will get worse over time at some point in there life - it could be day or it could be year or 2. . They are on there way for huge problems. I promise, I know what I am talking about here and the same in the vid because I experienced seeing it happen with sets I tested and thrown many in the trash afterwards,

Please watch the vid below and possible an huge eye opener for all and for engine builders who really knows nothing about fuel injectors. Not saying this in a bad way but an eye opener

Again I am not saying I AM THEE EXPERT but I sure try to follow and learn form the ones that are. I would never use these injectors from the 500 EFI period no matter of the engine, I am passing this info on because of the problems that can take place with these exact injectors. Do not take this FWIW take as solid advice.

anyways the vid is the same way I test injectors here among many other tests as well on top of. watch the vid no BS about it nor a marketing deal.

https://www.youtube.com/watch?v=APFKjP9upFg

Wildman_grafix

Wait, Bup are you saying you have found a injector that crosses over to the 500's and can be used with a stock tune?

Diamond Dave

I thought mine were bad but I'm glad those aren't mine! Scary stuff especially if you are none the wiser and just ran them as is.

AllDodge

iTrader: (1)

Unable to answer your question, just some comments

Thought about calling Merc to ask them about what they recommend as a replacement?
Did some looking and unable to find a replacement for the 500, only newer motors like the 525 and some others. Did find some on ebay and I'm guessing as new old stock, which in your case would probably want them check also.

If it was a diesel I would advise diesel injection service, being gas don't know who to advise.

BUP

iTrader: (9)

Bob I'm able to answer this somewhat and they are going to persons who work with injectors 8 hours per day probably 6 day a week. I am sending in his injectors to be matched across the board that's with dead times - flow volume match, sizing - pressure volumes matched and so on without needed a re cal of the ECM. With that said every single injector made some can not be exactly matched hence why I am sending them out.. Makes sense to me totally.

He has the vids from my testing of what going on with the injectors but I only tested 6 of his. - I could not have gave a crap about him nor his injectors - very easy for me to clean them a couple of passes and said pay me here is my bill good bye.

This would be so much less work and time for me. including time up here about all of this responding - correct ???

See since I do care, I am trying to put these injectors in way more better expert hands than mine or anyone up here or anyone in these vids to get their expertise for what is the best match with current injectors being offer.

These Multec injector designs are 35 year old out dated crap period. I know someone will come up here and say not mine or I have been building engines with those injectors for 30 years straight and be called out that I do know what I am talking about.

Within the last 7 years a lot of new advancements have came forth with injector characterization testing, designs and so forth.

The Merc cross injectors for these are 258 bucks per injector and Im sure its not going to even be anything close to what I will be trying to get and for a lot less money.

Anyone in for 258 bucks per injector thru Merc ?. This poor guy has 16 of them. And if anyone thinks Merc uses the best fuel injectors per their apps - go buy the ASNU machine and or other testing machines to test them and see what I am talking about. The 454 / 502 1998 thru 2001 has chit injectors as well that Merc uses and they are not even close for flow matching straight out of the box brand new ( so unbalanced) Just saying

BUP

iTrader: (9)

word of warning EBAY = crap injectors where is Smitty he has bought some ask him as well

fordf350

John: Like I said in my original post I do not question your knowledge. I was only asking if anyone has any other advice out there. I have been working on aircraft for over 34 years and it never hurts to learn new technics in maintenance. From the sounds of it I am not the only one by a long shot having to resolve the issues of these outdated injectors. I will tell the others that the six videos that you sent me of the test do show how bad my injectors are.

ALL_IN!

iTrader: (1)

I would trust BUP's word, just due to his contributions here on OSO.