If that 320 EFI motor had 24# injectors, and those injectors were marginal at best, you are likely nearing the DC limits of said injector at 320 hp. A better injector would give you some headroom against lean out destruction. I had a stock Merc (Kehein 26 lb) injector lean out and take a valve seat with it. That got 6 people in the boat to simultaneously say "uOhhhhh...." Imagine having a blender going full tilt and then drop a few bolts and washers inside. Same sound.

I imagine a lot like when a chunk of piston comes off and bounces around in the cylinder until it gets chopped up enough to get spit out the exhaust valve! One of those what was that moments!!

There is nothing that makes an injector "marine" or automotive. An injector is an injector. There are lots of shapes and sizes, connectors, resistances, offset curves, etc. There is also nothing special about marine efi management systems either, they are just cumbersome and not user friendly for tuning because they werent designed to be. Tuning a marine engine is different then automotive, but that's about it. The original bosch part number for the 320 is not a "marine" injector, I think they were used in some porsche application. If you've tested the other 24# injector that Sonic mentioned, I'd be curious to know the results. Unfortunately not every injectors advertised flow is at 3 bar, so it's hard to directly compare unless you know the test pressure. Thanks

One is never I said auto and marine fuel injectors do not cross period. I realize that that 100 %, auto injectors vs marine injectors can be the exact same part numbers. Some marine fuel pressures are not the same as apples to apples - auto engines vs marine engines, My point as well is, I would not recommend an out dated EV1 fuel injector as some are not even made anymore, I would rather use for one example a current EV14 FI that can be a direct replacement. . Electrically the current offers are way better among other things.

The 320 EFI was a Bosch injector inwhich yes Porsche did use Bosch injectors. But will add to say it is a Porsche injector only is not technically correct. It was a Bosch FI and this 320 EFI injectors is not MADE ANYMORE. NLA even thru Bosch. Another one of my points.

I posted this as well - a bosch injector and a bosch fuel pump used in the 320 EFI Merc. Like I said I even have the fuel injection testing tool for this set up.

marine fuel injection has always been behind the auto side by at least 10 to 15 years running. Marine OEM stock fuel injection just started using real wideband O2's for the Cat side. Marine fuel injection for the Inboard and I/O side just started with direct injection. I have 30 years of working on boats professionally . Certs in Indmar, PCM, Volvo Penta and Mercruiser just stating not bragging. I am no stranger with marine fuel injection especially anything that the OEM marine has incorporated from day one to curently.

Lastly a bit of jist with fuel injectors - they can look the same from one brand to another or even a more current offering that people google for their info however, even different style of injectors can seem and look 100 % fine but without testing them, you will never know 110 % if the operating characteristics and the require specific voltage compensation levels along with the required specific flow rates are what is needed for the direct cross fuel injector.(s)... Hopefully I made a great point here and is finally heard..

My referring the Auto side tuner guy was that he never seen a Motorola PCM 555 nor a 496 8.1 marine engine and never seen anything that does not use 02 sensors or an incorporated 02 sensor(s). Ever.

Some auto tuners think its like an OBD 2 system or only used MEFI controllers for the marine side was my direct point..

Yup, a lot of powersports don't use 02's nor 'common' ECU's and thus have not been 'hacked' by aftmkt EFI tuner / software individuals/companies.

Thanks SB for clearing up what I really was saying.

Hey go to 50 % of the auto tuners and asked them, have you even done a triple nickle ??? They will look at you and then ask - like what, 3 prostitutes in Vegas all at the same time ???

for those who do not know what the TRIPLE NICKLE is --



Its the ECM / PCM 555 Motorola - the Mercruiser installed controller / computer. And Merc outboards as well

LOL. I like that. Too funny.

It was only a couple years ago that you asked for help writing an efi technical article for some online publication, I'm glad that you have gained such vast knowledge on the subject since then. Instead of continuing to propagate the falsehood that marine efi is some kind of esoteric voodoo, maybe you could recommend what ev14 injector would be a direct replacement for the factory Bosch injector that flows 24.6 lbs per hour at 43.5 psi? Or how that injector is so much different then the replacement injector that Sonic mentioned, or the one I mentioned? I realize this is an outdated efi system, but instead of telling everyone how unique and difficult marine efi is, maybe you could offer a suggestion to assist the end user?

I called you because Bob M wanted to do a article with you included for build combo's and continued articles part 2 and 3. I asked in my voice mail to you what set ups are you installing to include in the story and then builds on top of. You never called me back but I still wrote that article plus many articles to this date about marine fuel injection.

The articles that I write for is in magazine print and online print - both. The magazine goes to 3 countries - 2000 copies across that range mostly the USA. . My questions were to you any related EFI build conversions that you wanted to throw into the mix and whatever you and Bob wanted to throw into together. Also since you are up in the cold north compared to what what I see with 90 plus degree water temps and 110 degree weather do your really see Vapor lock like we do.

Granted you do good work and will say great work on your side but if you are referring that I need any of your help with anything-on the marine side that I do - surely you are 100 % mistaken as I am taking your post here plus learned only in the past 2 years. This seems kind of a dog to me and or under the table stab.. Read some of posts thru out OSO and you will see I am no stranger to marine EFI nor the 496 nor for that matter any marine applications.

IF I AM misunderstanding your post then my bad completely 110 %. and I deeply apologize to you 1000 % on my end.