350 magnum efi 95

[warrenfine]

hi
this forum has been a great help in the past i am in desperate need of your assistance again.........

Boat - 1995 malibu with a 350 magnum efi

a few weeks ago when the boat got warm and i left it a while it was very very difficult to start.
the problem has been getting worse and now it wont start at all.

the buzzer comes on and then it swtiches off.

a while ago somone on this forum send me a link on how to use an LED to check the error codes - unfortunately i have misplaced the docs - can somone pls help me with the info.
any other ideas's
it seems like it could be flooding but its an efi - is this possible ?

any ideas

warren

 

[Bondo]

Re: 350 magnum efi 95

it seems like it could be flooding but its an efi - is this possible ?

Of Course,.......... Anything is Possible........

Have you pulled the Spark Plugs,+ Looked,..??......

Have you Checked for Spark,..??.....

For That Matter,...... Have you Checked Anything,..??.....

When was the last time the motor was Tuned Up,..??.....New Spark Plugs, etc......

 

[warrenfine]

Re: 350 magnum efi 95

i have done some checks .....

i changed the plugs yesterday - they are burning black in my opinion in good condition - i put new ones in incase.
the fuel here in jhb south africa - i use a lead replacemnt fuel - its duel fuel for use in leaded & unleaded applications.

once the boat starts - it idles well performs well doesnt cut out etc........


the batteries are new and str cranks well - thats about all i have checked.

warren

 

[Silvertip]

Re: 350 magnum efi 95

If the plugs are burning black they are not OK as that indicates an overly rich condition. You have a fuel system problem.

 

[warrenfine]

Re: 350 magnum efi 95

i just got the boat started again - i battled but it started.

when it stands overnight no problem it starts first time or if we are out skiing and i switch it off for 5 min no problem it starts - if it is warm and i leave it longer than an hour or so - it battles to start ...........

i assumed the black plugs was from the high altitude that we are at 6000ft.
there was no excessive carbon or residue around the electrolyte.

do you think the injectors or dripping and causing flooding - maybe the motor is running to rich for this altitiude.
i bought the boat from florida about 12 months ago.

i service it myself ...........

warren

 

[Don S]

Re: 350 magnum efi 95

If you are going to be doing all your own servicing, you are going to need the tools of the trade. The Rinda scan tool
http://216.230.203.183/marine/mtspec.htm
a DVM, and an EFI fuel pressure test guage and the OEM service manual (Merc manual #17) will all be needed to troubleshoot your problem.
The "Throw Parts at it till it works" method is a lot more expensive than the tools, and probably wouldn't work anyway.

 

[warrenfine]

Re: 350 magnum efi 95

warren again...

i have a friend with a rinder tool - he says it can plug into the ecu - to change or check settings.......

should i be messing with that thing or do other checks first - is their an ideal fuel mixture for this altitude.

it used to start ok ---- i dont know is that the problem ???
it has always smelt like there was excess fuel not burnt - no real excess smoke though........

any more ideas ?

warren

 

[warrenfine]

Re: 350 magnum efi 95

hi don

i only saw you reply after i sent the last one.

a rinder tool i can get - .......
i think the efi thing is the problem i must say there are very few places this side of the world that have all the correct equip - more butchers than techs.

do you think i should get fuel preasures first ?

warren

 

[Don S]

Re: 350 magnum efi 95

You can't do anything to adjust the fuel mixture, the EFI system (all of it) is designed to compensate for altituede changes.

it used to start ok ----

Everything always works fine till it breaks!

You have said the word "Warm" a couple of times, could you explain Warm?

Early on Bondo asked if you have done a tuneup? Not just spark plugs. Cap, rotor, wires, the fuel may be fine, but if you can't get spark to the cylinders it's not going to run.

Do you have the Service Manual I mentioned? If not, you don't stand a chance.

 

[warrenfine]

Re: 350 magnum efi 95

where can i get the merc manuel 17 from - can you give me a site address or a tel no ?

i think that would be a good start ?

will that give tips for the fuel settitngs aswell ?

the efi fuel preasure tester - will an normal automotive one work ?

 

[warrenfine]

Re: 350 magnum efi 95

Warm........

If i leave the boat overnight - it starts first time in the morning or if it stands a week it starts easy.

if i go for a ski or ride - it starts easy during rest breaks.

when i park the boat after it has been used (warm) and then try start it after an hour or 2 or 3 - i get this problem.

if i leave it for 6 hours or more it starts easy.

i understand how ridiculus this problem may sound - i am also dumfounded - the actual performance once going is good - no miss or stalls etc .......

warren

 

[newport dave]

Re: 350 magnum efi 95

Warren,
If you are still interested in code reading here is the info;

How to make a Marine EFI Code tool for under $1.00

Materials needed:

One 12volt resistor type LED light
One small paperclip cut in half


This home made code tool will work on most marine EFI systems with the ten pin DLC (Data Link Connector).

How to hook it up:

1) Ignition key “OFF”
2) Remove the cap from the Data Link Connector (DLC)
3) Slide the LED into the female terminals of position E and F on the DLC, making sure that the positive side goes into terminal F and the negative side into terminal E
4) Turn the ignition key to the “ON” position (LED should come on)
5) Insert the half paperclip into terminals A and B – This puts the engine in “Service Mode” - (you will hear fuel pump come on, and code will begin to flash on the LED)
6) Read codes by observing LED flashs. If the self diagnostic system is working it will flash code 12 – one flash, pause, two flashes, long pause – it will repeat three times. If other codes are present they will flash in order of lowest to highest.

For more details on how to read codes, clear codes, what “Service Mode” is, how to set base timing, etc. refer to appropriate service manual.

I don’t recommend making and using this tool unless you are confident that you can do it correctly. Hooking it up incorrectly could damage the ECM.

Dave

 

[warrenfine]

Re: 350 magnum efi 95

thanks dave

will always use it - it helped so much with map sensor last time i had a problem.

warren

 

[180shabah]

Re: 350 magnum efi 95

where can i get the merc manuel 17 from - can you give me a site address or a tel no ?

i think that would be a good start ?

will that give tips for the fuel settitngs aswell ?

the efi fuel preasure tester - will an normal automotive one work ?

Ebay is a great resource for manuals, usually alot cheaper than buying from a dealer.

The manual will not give direct fuel settings, the EFI systems handles all of these adjustments. It will tell how to diagnose problems with the components of the EFI system.

Yes, you can use an automotive fuel pressure tester, with all of the normal precautions - verify no leaks, run bilge blower, etc..

 

[warrenfine]

Re: 350 magnum efi 95

thanks 180

thats a great idea.

warren

 

[Reel Poor]

Re: 350 magnum efi 95

Here is a starting procedure you can try when you expect the problem to occure. Try this procedure at the time when you expect the problem to be present as your primary starting procedure. May help diagnois flooding problem.

Also check the coolant temp sensor for dirty/broken connectors. Should be a two wire (black/yellow wires) sensor at or near the thermostat housing.

CLEAR FLOOD MODE

If a engine floods it can be cleared by opening the throttle half way. Open the throttle handle until resistance from the secondary throttle is felt. The ECM will then open or "pulse" the fuel injectors at an air/fuel ratio of 20:1. The ECM will hold the air/fuel ratio at 20:1 as long as the throttle stays half open and the engine RPM is below 300. If the throttle is more than 75% or less than 50%, the ECM returns the air/fuel ratio to the richer "starting" ratio.

 

[warrenfine]

Re: 350 magnum efi 95

thanks reel

i will give that start up procedure a try, let you know what transpires.
i had a look at the injectors aswell the one is different from the other - i think one have them has been changed at some time or another.
the spray patterns look different from each other - that is from a visual inspection.

i will also look for dripping of injectors after the boat has been turned off.
i found a service manual on e-bay for 10$

thanks to everyone for the advice i will let you know what happens.
that one injector that is different - bothers me a bit.

can anyone tell me what rev's should i be getting at full throttle at this altitude of 6000ft.
at present i get 4200rmp - does this sound right ?

warren

 

[warrenfine]

Re: 350 magnum efi 95

hi all

if the injector that has been fitted is not the same as the original - could it be overfueling and the reason that the plugs are burning black ?

i took the number on the top of the injector and it is some type of aftermarket injector that i cant get any info on but it seems to be spraying more fuel than the original one............

it also looks like the housing that supplies the injectors with fuel preasure has a very slight drip - once every 5 sec or so - this is when the engine is running.

any comments from the experts on this.........
i thought maybe i should get the kit and replace both injectors and gasket between the housing.

it seems to start a lot easier with the CLEAR FLOOD procedure - not what it should be but definately better.

any advice

warren

 

[Reel Poor]

Re: 350 magnum efi 95

Do you have the engine serial # ?
Did you check it for codes?
Did you check the fuel pressure?

 

[imported_MORIVERRAT]

Re: 350 magnum efi 95

Warren,
I have the same symptoms with a 2000 5.7L EFI.
I've tracked it down to vapor lock. Do a search for "mercruiser EFI vapor lock", you'll be suprised the information you can find. I'm installing a check valve on the fresh water line from the fuel pump cooler to the thermostat housing. Seems "heat soak" causes the lock. If you can, just open all hatches and keep the blower going when the boat is stopped.