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gregy

Injector Upgrade on 99 w/ Monsoon

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gregy

Just wanted to pass this along.  Not sure if its been discussed before but this is what I did on My 1999 Response LX with Monsoon engine.   I was getting gas in my oil so after some discussion here I decided it was probably the injectors.  I pulled the injectors and sent them off to be cleaned and it worked for a year or so but then noticed it was happening again.   I did some research and found that a lot of car enthusiast were upgrading the same injectors we have in our boats to newer generations.  I ended up finding www.fuelinjectorconnection.com  and the guy suggested a modified Bosch Design III 24 lb, I went with Re-manufactured to save $.  They are tested and packaged as matched sets.   The originals were 27 lb but he recommended going down to 24 lb because the new design allows the fuel to burn more efficiently.   These injectors are not as tall as the original so they require some modification to fit properly.   Their PN was FIC7G2OC39.   I think this is a common use of these jnjectors so they can probably be found from other sources but this guy got back with me and seemed to know what he was talking about. 

Just a warning if possible start soaking all the fuel line connection and bolts with penetrating oil a day or so in advance.  My boats only has 355 hrs and is in really good condition but they were still corroded a bit.  There's two socket had bolts that require a 3/16" allen wrench on each side to remove the fuel rails.  I removed the fuel lines that connect the rails as well as the one that feeds the rails.   I used a line wrench (think 5/8") and an adjustable wrench on the fitting to keep from damaging the fitting or rail.  The electrical connectors have a wire clip, you push in on the clip and work the connector off gently.   I put some silicone grease for car brakes on all the fuel line connector threads and the 4 bolts to make sure they don't corrode up again.  The bolts were stainless and had a lot of corrosion where they went through the aluminum fuel rails.  I would have liked to replace them but it was late night when I was doing this so I used a wire wheel on a grinder and cleaned them up.  I liberally applied grease on the entire length of the bolt to resist future corrosion.   There's a standoff that is between the rail and the intake manifold watch it the first bolt i pulled out the standoff fell out and took a little while to find. 

I've been out about 5 times since and the boat has more power and is running better than it ever had.  It should help on fuel consumption as well. 

 

Edited by gregy

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Shastasurf

What kind of modification is required to get them to fit? I'm going to do the same soon.

1 hour ago, gregy said:

Just wanted to pass this along.  Not sure if its been discussed before but this is what I did on My 1999 Response LX with Monsoon engine.   I was getting gas in my oil so after some discussion here I decided it was probably the injectors.  I pulled the injectors and sent them off to be cleaned and it worked for a year or so but then noticed it was happening again.   I did some research and found that a lot of car enthusiast were upgrading the same injectors we have in our boats to newer generations.  I ended up finding www.fuelinjectorconnection.com  and the guy suggested a modified Bosch Design III 24 lb, I went with Re-manufactured to save $.  They are tested and packaged as matched sets.   The originals were 27 lb but he recommended going down to 24 lb because the new design allows the fuel to burn more efficiently.   These injectors are not as tall as the original so they require some modification to fit properly.   Their PN was FIC7G2OC39.   I think this is a common use of these jnjectors so they can probably be found from other sources but this guy got back with me and seemed to know what he was talking about. 

Just a warning if possible start soaking all the fuel line connection and bolts with penetrating oil a day or so in advance.  My boats only has 355 hrs and is in really good condition but they were still corroded a bit.  There's two socket had bolts that require a 3/16" allen wrench on each side to remove the fuel rails.  I removed the fuel lines that connect the rails as well as the one that feeds the rails.   I used a line wrench (think 5/8") and an adjustable wrench on the fitting to keep from damaging the fitting or rail.  The electrical connectors have a wire clip, you push in on the clip and work the connector off gently.   I put some silicone grease for car brakes on all the fuel line connector threads and the 4 bolts to make sure they don't corrode up again.  The bolts were stainless and had a lot of corrosion where they went through the aluminum fuel rails.  I would have liked to replace them but it was late night when I was doing this so I used a wire wheel on a grinder and cleaned them up.  I liberally applied grease on the entire length of the bolt to resist future corrosion.   There's a standoff that is between the rail and the intake manifold watch it the first bolt i pulled out the standoff fell out and took a little while to find. 

I've been out about 5 times since and the boat has more power and is running better than it ever had.  It should help on fuel consumption as well. 

 

 

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gregy

The directions say, "the Bosch injector is 1/4" shorter"  "however on the Bosch 3 we have installed a seat modification that puts install height in the rail identical to stock".   So to be clear the injectors were modified properly by the vendor.

I forgot, it says to lubricate the o-rings on the injectors.  I used the same silicone grease, Napa Sil-Glyde. I put a thin later on the o-rings as well as the holes in the intake and rails.   I work in automated equipment maintenance and silicone grease is what we use in our worst environments.  

Edited by gregy

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Nitrousbird

I'd be weary of changing fuel injector sizes.  That "burn more efficiently" means nothing more than...if true...the injector atomizes the fuel better than the old injector.  The ECU tune is expecting the 27lb fuel injector and has an expectation of how much fuel is being delivered during its duty cycle.  A smaller injector leans that out.

Mind you, it is a small change.  The problem with boat engines is that it doesn't have O2 sensors to help make any adjustments on the A/F ratio, with the only metering being temp, MAP and knock sensing.  My concern would be running lean. 

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airshark360

Without a proper tune the computer will fight that smaller injector, the extra power is most likely your motor running lean. As a little lean is okay too much will burn that baby up. Keep us updated after you get some time on those injectors. 

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23LSVOwner
2 hours ago, Nitrousbird said:

I'd be weary of changing fuel injector sizes.  That "burn more efficiently" means nothing more than...if true...the injector atomizes the fuel better than the old injector.  The ECU tune is expecting the 27lb fuel injector and has an expectation of how much fuel is being delivered during its duty cycle.  A smaller injector leans that out.

Mind you, it is a small change.  The problem with boat engines is that it doesn't have O2 sensors to help make any adjustments on the A/F ratio, with the only metering being temp, MAP and knock sensing.  My concern would be running lean. 

From memory pretty much every fuel injected inboard boat engine has O2 sensors which are used to monitor and adjust the A/F mixture.

 

Maybe you are thinking of the carburetor days?

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gregy

I had the same concern with the open loop system and discussed it with vendor he thought these would be closest to the same as stock and not need recalibration.   So far they are working good.  I'll check the plugs in a few weeks see what they look like.

Edited by gregy

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electricjohn

Those injectors reduced your fuel flow by 1/8 or 12%.  I would think A/F ratio calibration of the ECM is leaning on the rich side for safety being it is an open loop system, but 12%?

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MadMan
58 minutes ago, gregy said:

I had the same concern with the open loop system and discussed it with vendor he thought these would be closest to the same as stock and not need recalibration.   So far they are working good.  I'll check the plugs in a few weeks see what they look like.

You're probably still rich, I measure mine ('00 MEFI 3) with a side band O2 and the A/F was mid-10's at WOT, about 20% rich.  I'll bet you increased your power as well as reduced your fuel consumption.

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Nitrousbird
1 hour ago, 23LSVOwner said:

From memory pretty much every fuel injected inboard boat engine has O2 sensors which are used to monitor and adjust the A/F mixture.

 

Maybe you are thinking of the carburetor days?

There are no O2 sensors on mine. I don't think I have ever seen them on non-catted manifolds. 

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23LSVOwner
Just now, Nitrousbird said:

There are no O2 sensors on mine. I don't think I have ever seen them on non-catted manifolds. 

Can you upload some pics of your manifolds?

I've not ran across any injected engines without them.

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MadMan
21 minutes ago, 23LSVOwner said:

Can you upload some pics of your manifolds?

I've not ran across any injected engines without them.

I have no O2's either, manifolds look like this:

http://www.michiganmotorz.com/indmar-exhaust-manifold-exhaust-ports-p-4526.html?gclid=CIu1g9Gfx9ICFUY8gQodAcYIKQ

And yes, mine is MPI.

 

 

Edited by MadMan

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23LSVOwner

Wow, at least I learned something today!

Haven't wrenched on an older 350 in a LONG time.

No O2 sensor feedback is an awful way to run. You have to set up your timing and fuel mapping for worst case conditions to keep the motor safe so it makes it inefficient as hell.

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MadMan
6 minutes ago, 23LSVOwner said:

Wow, at least I learned something today!

Haven't wrenched on an older 350 in a LONG time.

No O2 sensor feedback is an awful way to run. You have to set up your timing and fuel mapping for worst case conditions to keep the motor safe so it makes it inefficient as hell.

Yep, it's pretty crude, no MAF either. A carburetor might be more efficient.

 

Edited by MadMan

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RTS

One problem I see with leaning out the engine is there is no practical way to monitor each cylinder individually, like those who operate Lean of Peak in small airplanes have.  While the aggregate A/F might be rich, it is possible that an individual cylinder (or two) could be running too lean.  Especially since these aren't direct injected engines.  Probably why the engines pre-O2 sensor all run rich...provides margin of error for all cylinders.

Edited by RTS

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MadMan
5 minutes ago, RTS said:

One problem I see with leaning out the engine is there is no practical way to monitor each cylinder individually, like those who operate Lean of Peak in small airplanes have.  While the aggregate A/F might be rich, it is possible that an individual cylinder (or two) could be running too lean.  Especially since these aren't direct injected engines.  Probably why the engines pre-O2 sensor all run rich...provides margin of error for all cylinders.

In addition to this, the MEFI doesn't know if the sensor reading it has (MAP, TPS, Temp) are valid.  But worse, it has no fuel pressure feedback which can cause air/fuel problems.

Also, since mine is MPI, it has 1 injector for each cylinder, which eliminates fuel distribution problems caused by the intake manifold design that is common with TBI and carbureted engines. 

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Shastasurf

So........I guess I'll have to buy an air to fuel ratio gauge and sensor too, lol.  I've spoke with same guy atfuel injector connection and  almost ordered the same injectors, and was still planning on it.    But you guys are scaring me a little, and making me reluctant.   My boat doesn't have an o2 sensor and to me smells like it's running rich.  Please report back, I would think better atomization is good thing.   Let's please see pics of plugs!

17 hours ago, gregy said:

I had the same concern with the open loop system and discussed it with vendor he thought these would be closest to the same as stock and not need recalibration.   So far they are working good.  I'll check the plugs in a few weeks see what they look like.

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RudyMuller

I just put the same injectors in!  Can't test the boat out until April 1st. 

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gregy

Lots of replies,  Thanks for all the input.  I had the boat out 2 more times this week.  The boat has always had a fuel smell at idle like it's running rich, hard to say if it was just one or so cylinders.  I pulled the plugs several times before to see if I could tell which cylinder way running rich but the plugs always look the same.  The boat is used almost exclusively on a private lake for slalom, so it spends most of the time between 2800 to 3800 rpm range.  I'm thinking at higher RPMs if there was a bad injector it was normalizing.   The fuel smell at idle is gone now.  I think the plugs in the boat now are about 8 months old.  Soon as I have some time I'll pull a few plugs and see what they look like. 

BTW, My buddy's 08 Mastercraft has a GM 5.7L non-cat engine with O2 sensors.  I was told that was the only year they came that way. 

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electricjohn
On ‎3‎/‎8‎/‎2017 at 5:57 AM, Nitrousbird said:

  The problem with boat engines is that it doesn't have O2 sensors to help make any adjustments on the A/F ratio, with the only metering being temp, MAP and knock sensing.   

Don't forget distributor reference (RPM's).

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electricjohn
8 hours ago, gregy said:

 

BTW, My buddy's 08 Mastercraft has a GM 5.7L non-cat engine with O2 sensors.  I was told that was the only year they came that way. 

That was around the time MEFI-5 started showing up.  Indmar engine, I'm guessing, Mastercrafts version of the Monsoon.

Edited by electricjohn

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Nitrousbird
1 hour ago, electricjohn said:

Don't forget distributor reference (RPM's).

Plenty of pre-cat EFI boats that don't have distributors (mine doesn't).  I don't necessarily considering CPS metering as it is showing a reference, not taking a measurement.  That said, the ECU still uses that information.  Same as the TPS reference.

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Engine Nut
On ‎3‎/‎8‎/‎2017 at 7:39 AM, 23LSVOwner said:

From memory pretty much every fuel injected inboard boat engine has O2 sensors which are used to monitor and adjust the A/F mixture.

 

Maybe you are thinking of the carburetor days?

The first engines with O2 sensors were in the 2007 model year when we started using catalytic converters. Prior to that, I am not aware of ant inboard that had O2 sensors.

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jbower

Did you ever check what your fuel pressure was? Seems more than likely a clogged fuel pressure regulator causing your problems 

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gregy

I haven't checked the Fuel Pressure recently.  I did replace the regulator about a 1.5 years ago because it was leaking.  First regulator I got was bad right off the bat by the way.

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