merc 150 start up problems

[spanky]

Subject: merc 150 efi dies out on start up?
Submitted by spanky (216.106.246.233) on 2/3/2001

i am hoping someone else has had this problem. i am going broke paying for a diagnosis with no findings.here are the
symptoms: i start the engine and begin to accelerate the boat onto plane.at about 1800 -2000 rpm the motor dies as if you
shut the key off.i pull shift back to neutral and it starts immediatly.i again advance the throttle and the same thing happens
again and again and again. this problem does not occur all the time.i have been told that diagnostically the motor spec's out
100%.i pay for the labor go out and try to use the boat and it will happen again.does not seem to be temp related.i have
checked for water in fuel which is not the case, and am at a loss on what to try.i fish offshore alot in the great lakes and can't
trust this motor at this time.the times this problem goes away or does not occur the engine runs out a-1 upto full throttle. it has
been suggested that the problem may be in the voltage regulator producing too much current and then shutting down the high
pressure fuel pump.

any of you motor gurus out there PLEASE HELP.i would like to call on land line if you think you have a constructive
guess...please post or e-mail me.our hard water is soon to be gone.

thanks,

spanky

[ebijack]

first change your fuel filter. also you need to look at your fuel pickup hose in your tank. some have filters on the end, others don't. you want that fuel line approx. 3/8 to 1/2 inch off the bottom of your tank. there have been cases where the fuel line moves/swings to close to the bottom of the fuel tank and stops/slows fuel flow. if all that's ok, i'd look next at your spark plugs (see if they have all been firing ok) and your coils or the trigger for your spark. hope that helps

[ml]

can you give more info,like what was done by your mechanic,like if he went through a lync and sync,was the tpi checked,throttle position sensor,worked on efi for quite a while,sounds electrical but with a little more info i might be able to help you,but you say it starts right back up and a tpi will cause a lean condition,bad idle hard starting,or dies at throttle up,really doubt its plugs,or fuel filter cause your shop should have replaced them,any more info will help me,i will give it my best shot.

[walleyebob]

hey spanky! this may or may not sound stupid but change your primer bulb over to the new mercury primer bulb, ask your tech he knows which one im talking about . it came out last year, i had your exact same problems, and it worked for me ,it was a simple fuel starvation problem. id say start here and put it on your self,saves time moneyand aggrevation, it cant hurt you will need one in the future any ways , i sure hope this helps . take care wb

[spanky]

ml & ebjack,
thanks for your replies. i have replaced the fuel filter,also upgraded fuel pump per merc. upgrade(something to do with a mylar switch upgrade)pump itself was also replaced.pick up line in tank is off bottom of tank about 1 inch.all the techy stuff you mentioned ml was checked and only thr tpi was slightly readjusted.i have had 2 top tournament tweeking type mechanics look at this with no tangible findins.the last time the boat was tested ,the guy ran in over a period of two days several times and it never failed.when i got it back i also ran it and it never failed.then i trailed to erie and first time out it did it thing.very ghost like as far as being able to get it to fail with any type of predictable pattern.the stater has also been mentioned,but ruled out since when the boat does run it performs 100 at all speeds.if you want to e-mail me your phone number ml i'll call you to rehash the symptoms.
thanks for your interest and input.
spanky

[spanky]

the bulbs have been replaced with the upgraded ones.it was the first thing i tried.
spanky

[EyeBoy]

Spanky;
Has the fuel lines been checked to see if the pump is sucking air, from a cracked fitting or hose. Also, once in a great while, there has been hoses that have had the inner liner bubble or tear, thus causing fuel starvation. OBTW, when the eng was tested at the shop, was it put under load? Sometimes these problems seem unique to the load involved in getting the boat onto plane. Hang in there.
ON-PLANE!!!TOM

[,]

,

[Eye Guy]

I had the same problem to.
I changed the primmer bulb (you need the one with a yellow ring around one end)
Have not had the problem since.

[R,P,]

Spanky, Is your key switch on your shifter console. If it is check for bare wires conected to your switch. If wires are aginst moveing parts it will ware off insulation and short out, but should blow fuse. I have seen this happen its a reel hair pulling experance. Just a thought. Good luck.

[tom]

I concur with eyeboy.Last year i decieded to change my fuel hose and bulb.Had the same problem,she would just get up on plane then die.Had it in the shop several times.They pulled the carbs & cleaned them,did a compression test on it,rebulit the fuel pump.All to no avail.After the third time of on water testing and getting the same results,and not to mention a mounting repair bill,I switched back to the old hose & bulb.Presto,she ran perfect.I called the repair shop & told them of my findings.Their reply was since the could'nt test it under load it was diffcult to determine the the hose was the problem.Try a new hose & blub assembly,but use the quicksliver product.

[MUSIC MAN]

i prefished on erie a few years back with a very famous pwt pro who ran a lund prov le and had the same trouble .the fuel ball was flatten out when we got on plane,it was sucked FLAT, so no gas was getting to the engine. we changed it and it was find

[Eye Catcher]

Where your fuel line hooks up to your tank there is an anti siphon valve. If anything gets caught here it can cause this problem.
It is a check valve with a ball and spring.
Take your fuel line off at the tank.
With a 9/16 wrench unscrew the anti siphon valve.
Install new one with a little teflon tape on theadred portion of valve.
Hope this takes care of it for you.
Also if you just replaced the primmer bulb go back and replace the fuel line from the tank all the way to the motor.
I have seen these fuel line colapse inside causeing this same problem.
What kind of boat is it on?

[BigWink]

>Subject: merc 150 efi dies out
>on start up?
>Submitted by spanky (216.106.246.233) on 2/3/2001
>
>
>i am hoping someone else has
>had this problem. i am
>going broke paying for a
>diagnosis with no findings.here are
>the
>symptoms: i start the engine and
>begin to accelerate the boat
>onto plane.at about 1800 -2000
>rpm the motor dies as
>if you
>shut the key off.i pull shift
>back to neutral and it
>starts immediatly.i again advance the
>throttle and the same thing
>happens
>again and again and again. this
>problem does not occur all
>the time.i have been told
>that diagnostically the motor spec's
>out
>100%.i pay for the labor go
>out and try to use
>the boat and it will
>happen again.does not seem to
>be temp related.i have
>checked for water in fuel which
>is not the case, and
>am at a loss on
>what to try.i fish offshore
>alot in the great lakes
>and can't
>trust this motor at this time.the
>times this problem goes away
>or does not occur the
>engine runs out a-1 upto
>full throttle. it has
>been suggested that the problem may
>be in the voltage regulator
>producing too much current and
>then shutting down the high
>
>pressure fuel pump.
>
>any of you motor gurus out
>there PLEASE HELP.i would like
>to call on land line
>if you think you have
>a constructive
>guess...please post or e-mail me.our hard
>water is soon to be
>gone.
>
>thanks,
>
>spanky


make sure your fuel line is not pinched by other lines going into your motor

[redbone]

spanky try this. hook a volt meter to the starting battery. bring up the rpms, watch the meter, you should notice an increase in the volts at the battery from 12 up to about 16volts, then it should level off to 12. if it climbs up to 18 doesnt return to 12 and dies, then it sounds like your stator has a burned tower and/or your volt reguletor is bad. this happened on my 200 efi. what happens is the exess voltage over heats the ecu and it shuts down to protect its self. in the manual that may be explained in the electrical section. also there is a upgraded regulater from mercury cause some problems were found, this is in a service bullitin from merc. your mechanic should have this.
good luck let us know what happens.
bob piette
think spring