1998 Mariner Mag EFI 150 - Runs Rough then Dies

[jeffersondodson561]

Re: 1998 Mariner Mag EFI 150 - Runs Rough then Dies

This motor is an altenator driven ignition, meaning that your battery has nothing to do with the ignition components. How many batteries do you have in the boat. The battery is mainly for ECU and fuel injection components. What is your pressure at the fuel pump? Has this motor been sitting for some time? Untreated fuel?

 

[4winnsskipper]

Re: 1998 Mariner Mag EFI 150 - Runs Rough then Dies

This motor is an altenator driven ignition, meaning that your battery has nothing to do with the ignition components. How many batteries do you have in the boat. The battery is mainly for ECU and fuel injection components. What is your pressure at the fuel pump? Has this motor been sitting for some time? Untreated fuel?

I'll get you the fuel PSI tomorrow. I bought a tester tonight.

What im thinking is this battery may be bad or have a bad cell or something and is causing this erratic issues with the ECU/fuel pump. Im pretty certain the issues lie on the fuel side of the motor since i know i have spark. Im going to also put a new battery in the boat since the battery thats in it, came with the boat when i bought it anways. And there is one battery as of right now for the motor. The second is in the bow and only connected to the front trolling motor.

 

[jeffersondodson561]

Re: 1998 Mariner Mag EFI 150 - Runs Rough then Dies

If you have a battery charger (which every boater should have) you could put the charger on 40 amp charge and see if your condition improves this will usally, not always, give you an idea of the battery condition.

 

[Faztbullet]

Re: 1998 Mariner Mag EFI 150 - Runs Rough then Dies

Uh... You test a battey with a load tester, not a charger...and customers wonder why their rectifiers fail. You should never have to charge a late model motor starting battery unless something was left on and drained it. If thats the case you should still disconnect a engine lead to charge battery and never boost a battery with motor leads attached. Mercury and Evinrude does not recommend that you have a onboard charger attached to starting battery and discard wing nut and use a locking nut. Also use the correct battery as your engine min is 490 CCA and 630MCA and do not use a deep cycle for a starting battery. If this boat has been setting,drain the fue tank and discard and start with fresh fuel..

 

[4winnsskipper]

Re: 1998 Mariner Mag EFI 150 - Runs Rough then Dies

Uh... You test a battey with a load tester, not a charger...and customers wonder why their rectifiers fail. You should never have to charge a late model motor starting battery unless something was left on and drained it. If thats the case you should still disconnect a engine lead to charge battery and never boost a battery with motor leads attached. Mercury and Evinrude does not recommend that you have a onboard charger attached to starting battery and discard wing nut and use a locking nut. Also use the correct battery as your engine min is 490 CCA and 630MCA and do not use a deep cycle for a starting battery. If this boat has been setting,drain the fue tank and discard and start with fresh fuel..

Faztbullet, boat has not been sitting, and the 8 gallons of the 24 in it are very fresh from the pump only a week old.

Im running out of ideas, im going to take the battery to be tested first as last nights power loss to motor, then it coming right back is a sign i think. What would cause something like that? It was exactly as if i disconnected the power cables from motor to battery then reconnected them, but obviously i didn't.

Thanks for sticking with me Fazt, if we find out what this is i'd be willing to paypal you some cash.

 

[jeffersondodson561]

Re: 1998 Mariner Mag EFI 150 - Runs Rough then Dies

Uh... You test a battey with a load tester, not a charger...and customers wonder why their rectifiers fail. You should never have to charge a late model motor starting battery unless something was left on and drained it. If thats the case you should still disconnect a engine lead to charge battery and never boost a battery with motor leads attached. Mercury and Evinrude does not recommend that you have a onboard charger attached to starting battery and discard wing nut and use a locking nut. Also use the correct battery as your engine min is 490 CCA and 630MCA and do not use a deep cycle for a starting battery. If this boat has been setting,drain the fue tank and discard and start with fresh fuel..

Can you please provide the reference material that states Merc/BRP does not like to see on board batt chargers, I must have missed those.

 

[4winnsskipper]

Re: 1998 Mariner Mag EFI 150 - Runs Rough then Dies

Another Update...Still not looking promising...

Here are two videos i made showing what the fuel pressure is. I was hoping to find no or low fuel pressure so atleast i'd have a lead, NOPE. seems to be between 30-40psi so i think the fuel pump(s) are fine.

I also had the battery checked out by the local REMY battery, they ran it through about five tests, all came back "good". So i then cut off the old terminals off the wires that were on there and put new terminals on, and sanded off some surface rust on the terminals. Reconnect them with a locking nut, then sprayed the terminals down with terminal protector and reinstall rubber boots over them. So it seems i've ruled out the battery.

So something is wrong, i used a spark tester and get spark on all cylinders, then i have fuel pressure. So it seems its either the ECU itself, or the timing went off somehow, or "bad gas" (even though i pumped gas into a clear container and saw no water....

Very frustrated....Any thoughts?

Links to video >>

http://www.youtube.com/watch?v=Sf2JJuAKVRU

http://www.youtube.com/watch?v=vOOUW502GKo

 

[4winnsskipper]

Re: 1998 Mariner Mag EFI 150 - Runs Rough then Dies

UPDATE YET AGAIN: A buddy had a great idea, and that was to get a 6 gallon fuel tank and put fresh gas in that, then hook the motor up to that tank. Well we did that, and i even re-drained the VST and emptied all fuel out of the fuel filter, primed the bulb, and it started and ran great. Let it idle in the driveway for 15 minutes. Turned it off. Restarted, idled again for 5 minutes no problem. So at this point im pretty giddy again.

So i toss the kicker motor back on just in case the main craps out again and we go down to the lake, drive it around with the 6 gallon tank on it and had ZERO problems for the 30 minutes we were out there driving around...

So im guessing i got some real bad guess when i filled up last time. I didn't see any water in the gas but im going to re-test again.

My only concern is that maybe one of the fuel pumps is going/gone bad still and it only ran great because of the shorter line i used making it easier to suck gas out of the spare 6 gallon tank, or am i nuts?

And most importantly, how the heck can i dispose of 20 gallons of fuel the internal tank has!?!?! I do not want to run this gas through my car thats for sure!!!

Ideas?

Attached are pictures of the fuel from the main internal tank. i still don't see any water though...can it simply just be "bad" gas?

 

[4winnsskipper]

Re: 1998 Mariner Mag EFI 150 - Runs Rough then Dies

no one?

 

[4winnsskipper]

Re: 1998 Mariner Mag EFI 150 - Runs Rough then Dies

is this thing on???? hello?

 

[CharlieB]

Re: 1998 Mariner Mag EFI 150 - Runs Rough then Dies

Only the primary fuel pump sucks, then pushes fuel to the VST, from there the high pressure pump just pushes. Rebuild the primary pump.

As for all the old fuel, most lawn mowers will burn just about anything you pour in the tank.

 

[4winnsskipper]

Re: 1998 Mariner Mag EFI 150 - Runs Rough then Dies

Only the primary fuel pump sucks, then pushes fuel to the VST, from there the high pressure pump just pushes. Rebuild the primary pump.

As for all the old fuel, most lawn mowers will burn just about anything you pour in the tank.

so do you think my old pump is crap and it only works on the smaller 6 gallon tank?

BEcause this thing runs great on the spare 6 gallon tank VS what gas is in the internal tank...

 

[Faztbullet]

Re: 1998 Mariner Mag EFI 150 - Runs Rough then Dies

Can you please provide the reference material that states Merc/BRP does not like to see on board batt chargers, I must have missed those.

I will dig em up from my CDI/Amtech bulletins ...
4winns check to see if have the grey fuel line with RED writing on it from tank to engine,if so replace it as they come apart internally and restrict fuel flow.

 

[CharlieB]

Re: 1998 Mariner Mag EFI 150 - Runs Rough then Dies

It can't hurt to rebuild the primary pump, BUT, it IS working as the VST would run low on fuel and power would fail if the primary pump was not doing its job.

Faztbullet may have solved the problem, alcohol in our fuels rapidly degrades older fuel hose, the inside liner of the fuel tank hose may be restricted, collapsed, split and acting like a flapper valve. Replace that hose and retest.

Take the 6 gal tank along just in case.

 

[4winnsskipper]

Re: 1998 Mariner Mag EFI 150 - Runs Rough then Dies

I will dig em up from my CDI/Amtech bulletins ...
4winns check to see if have the grey fuel line with RED writing on it from tank to engine,if so replace it as they come apart internally and restrict fuel flow.

from the looks of it it's just a black 3/8 rubber fuel line from internal tank nipple to nipple that goes through transom...this will be a pain to replace but definitely a good idea.

Every time after trying to troubleshoot this engine, i'd drain the VST tank and it would be full (seemingly at least from the amount that drained) of gas... so i think the mechanical fuel pump is working still.