EFI not running well

[Needafunboat]

OK, so I had this problem late last year, but I guess I need to start working on it now. My 3.0L 225 EFI (1996) did a few strange things:

1) When starting cold, I had the trim up fairly high (shallow ramp). It would run fine for a minute or two and then not want to idle. I could give it some throttle, it would bog and I'd make it out to the deeper water. It seemed to get better when I hit deep water and trimmed down. Also ran fine on muff's with trim the whole way down when I winterized it. It seems like the trim position effected how it ran which makes absolutely no sense considering the high pressure fuel pump for the EFI.

2) The other strange thing it did was after about 30 sec at WOT running fast, it would stall a few times. It would eventually run better, but I'm not sure why running fast like that would cause a stalling issue. Maybe another fuel pressure issue?

3) Boat would not pull well at all one day - it would barely pull a wakeboarder. I changed plugs (very oil and dirty - rich looking). It ran perfectly with the new plugs. Even started and idled better.

4) I had been a little lazy about adding fuel inj. cleaner this pasat year. The previous year I was diligent.

So my guess is dirty injectors - with a possible second issue of a low fuel pressure - maybe a dirty screen or something. I know that two years ago, my boat mechanic buddy checked the fuel pressure and cleaned out the little mixing tank and screen in there. I can clean and test the injectors at work, so that's a no-brainer.

What are your thoughts? Mark - are you out there??

 

[Rob B]

OK, so I had this problem late last year, but I guess I need to start working on it now. My 3.0L 225 EFI (1996) did a few strange things:

1) When starting cold, I had the trim up fairly high (shallow ramp). It would run fine for a minute or two and then not want to idle. I could give it some throttle, it would bog and I'd make it out to the deeper water. It seemed to get better when I hit deep water and trimmed down. Also ran fine on muff's with trim the whole way down when I winterized it. It seems like the trim position effected how it ran which makes absolutely no sense considering the high pressure fuel pump for the EFI.

2) The other strange thing it did was after about 30 sec at WOT running fast, it would stall a few times. It would eventually run better, but I'm not sure why running fast like that would cause a stalling issue. Maybe another fuel pressure issue?

3) Boat would not pull well at all one day - it would barely pull a wakeboarder. I changed plugs (very oil and dirty - rich looking). It ran perfectly with the new plugs. Even started and idled better.

4) I had been a little lazy about adding fuel inj. cleaner this pasat year. The previous year I was diligent.

So my guess is dirty injectors - with a possible second issue of a low fuel pressure - maybe a dirty screen or something. I know that two years ago, my boat mechanic buddy checked the fuel pressure and cleaned out the little mixing tank and screen in there. I can clean and test the injectors at work, so that's a no-brainer.

What are your thoughts? Mark - are you out there??

Anthony,
I had similar issues with the previous mate (1999 200 EFI Merc). I could run WOT to a no wake zone then as I idled thru the motor would shut off. My problem was the fuel pump, bought a fuel pump kit and added some stablizer to the fuel tank. That did the trick. Hope this helps.

 

[Needafunboat]

CM, Thanks.

What did that fuel pump kit cost you and how hard was it to put in? Did you also check the screen in the tank? Thanks for the info!

 

[Rob B]

CM, Thanks.

What did that fuel pump kit cost you and how hard was it to put in? Did you also check the screen in the tank? Thanks for the info!

I don't remember how much the fuel pump kit cost, all receipts are with the Pulse170. I got mine from the local merc dealer here. The kit wasn't hard to put in, looks like this:http://www.sterndrive.info/mercury-outboard-parts/mercury_mariner_fuel_pump_kits.html. I didn't check the screen in the tank, but when I did the floor resto and pulled the tank it had trash/gunk particles in the bottom. I cleaned the tank and added stablizer to the gas.

 

[mkhammer]

I can look up the cost of a fuel pump for you I will be going to the shop today. If you feel you can do it your self I recommend a shop manual I sell them. You should check your fuel pressure and take the steps to check the whole fuel system out lined in the manual. Fuel lines, from tank to TB's, check manifold bolts and run through everything. If you do change the pump they are pretty easy to remove. You will need a remote fuel tank with a 50:1 mix to run your engine to prime the oil injection lines. Or engine damage can occur. You need to follow steps to do it right and replacing the pump without checking the whole system could lead to trial by error. Replace lines if needed and all ties, make sure all lines are tight
AS you may know it is recommended to add Stabil to your fuel every other tank of gas on fuel injected engines, It helps keep a carb engine clean as well and threat before storage.
This is most manufacturers recommendations.

 

[Check This]

OK, so I had this problem late last year, but I guess I need to start working on it now. My 3.0L 225 EFI (1996) did a few strange things:

1) When starting cold, I had the trim up fairly high (shallow ramp). It would run fine for a minute or two and then not want to idle. I could give it some throttle, it would bog and I'd make it out to the deeper water. It seemed to get better when I hit deep water and trimmed down. Also ran fine on muff's with trim the whole way down when I winterized it. It seems like the trim position effected how it ran which makes absolutely no sense considering the high pressure fuel pump for the EFI.

2) The other strange thing it did was after about 30 sec at WOT running fast, it would stall a few times. It would eventually run better, but I'm not sure why running fast like that would cause a stalling issue. Maybe another fuel pressure issue?

3) Boat would not pull well at all one day - it would barely pull a wakeboarder. I changed plugs (very oil and dirty - rich looking). It ran perfectly with the new plugs. Even started and idled better.

4) I had been a little lazy about adding fuel inj. cleaner this pasat year. The previous year I was diligent.

So my guess is dirty injectors - with a possible second issue of a low fuel pressure - maybe a dirty screen or something. I know that two years ago, my boat mechanic buddy checked the fuel pressure and cleaned out the little mixing tank and screen in there. I can clean and test the injectors at work, so that's a no-brainer.

What are your thoughts? Mark - are you out there??

Your 3.0 is a prime candidate for all the up grades offered by Simon which I believe offers an upgraded fuel pump Lighter and balanced flywheel. For about 1500 bucks you could bring that older 3.0 to a new dimension. I don't know what your budget is but it is definately worth a call.

 

[Needafunboat]

'hmmmm $1500 is definately within my budget, and who doesn't want to go faster?! but for now driveability is my key concern. I spoke with Lee at Simon a while ago about the 3.0 EFI problem of accelerating when pulling back from WOT. His explanation made sense to me and he can reprogram the ECM to fix it. But it's not a $300 problem, only shows up on top speed runs and if you know about it, you can go WOT and then pull back 1/4 and then ease back in.

The strange thing is that with clean plugs, all symptoms seem to go away, and the plugs seem to load up after maybe 4 days of running. I think I'll check the injectors first.

MK and CM - Thanks for the info!! I do have a clymer manual, but I'd probably just have my buddy do it, he's a certified merc. mechanic and is looking for side work. He's pretty by-the-book - great info. about priming!

I didn't know about stabil every other tank, but I do put it in on the last day out - about 15 minutes before we will hit the ramp so it gets into the system. I normally run fuel injector cleaner every other tank (but like I said, I was a little lazy this year - and that's when the problems started).

I need to bring the injectors to work to clean and flow them. I'll also see if I can get OEM part numbers (I think mine our made by Siemens). If so, I could maybe find a far cheaper source. We sell injectors for around $10 each to the OEM's. I think they go for around 10x that in the aftermarket - OUCH!

 

[ndaniels]

You better get that thing running good before you come down this way!

 

[hotdaddy27]

Excuse me for just glancing over the thread, but did anyone mention dirty/worn out injectors?

This could be causing the signs you are seeing on the Plugs.

Coils can do crazy things as well. I chased a coil problem for a while on one of my EFI motors.

HD

 

[ndaniels]

Needafunboat can clean them where he works... he thought it may be dirty injectors in the first post.




I know if he's gonna come play in my pool this march, he better have it running top notch!

Anthony- hope to see you at the lake this spring when you come down

 

[Master Wrench]

Sounds like a fuel delivery problem. Check and see if the fuel line you have on your boat is grey. If it is squeeze it and see if it feels softer or kinda gooey in spots. If so then pull the hose off where it connects to the primer bulb and look in it. See if the inner liner of the fuel hose is collapsed and falling apart. If it is replace all the greay fuel line with new and the primer bulb. Then rebuild the vacuum fuel pump on the engine. Not to difficult and the kit runs in the mid $20 area. Then re-run engine and see if it got any better. Let me know what you find please.

Thanks!

 

[Needafunboat]

Thanks for the info. John! I'll check it out in the spring when I get the boat back from Kary's storage palace (not a typo...) and get this thread going again.

My two '95 seapoos had those same fuel lines on them and i replaced them all, and then cleaned the carb screens - they were maybe 1/3 plugged with the inner fibers.

I need to get Kary to send me those injectors so I can at least check them out - I've been meaning to to it for a while now.