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Dominick
Dominick, Marine Mechanic
Category: Boat
Satisfied Customers: 1009
Experience:  25 Years Experience as Mechanic, 20 Yrs Boat Yard Owner/Mechanic, Factory Certified
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2000 Mercury 150efi looses fuel injection pulse when hot

Customer Question

2000 Mercury 150efi looses fuel injection pulse when hot
Submitted: 8 months ago.
Category: Boat
Expert:  Charles replied 8 months ago.

Hello, my name is***** will assist you.

Would you please post the serial number of the engine?

Customer: replied 8 months ago.
Ot101902
Customer: replied 8 months ago.
Boat sat for 2.5 years inside never had any issues before this changed all filters,tuned up,batteries,etc before use after the long storage first time out ran for about 15-20 minutes and cut off did some testing and found out that it lost fuel injector pulse after it cooled for about 15 min started again and made it back to dock
Expert:  Charles replied 8 months ago.

How are you testing for the pulse?

Customer: replied 8 months ago.
Noid light and dry run off of aerosol can and run great long as I provide fuel
Expert:  Charles replied 8 months ago.

Are you running the engine with the front of the air handler off to get to the harness to install the noid light?

Are you sure that you are not losing fuel pressure?

Customer: replied 8 months ago.
No connected noid light at round harness plug at side of air handler and had fuel pressure gauge on test port at same time of testing
Expert:  Charles replied 8 months ago.

Is your Noid light a 4 pin? Mine is only a 2 pin.

Expert:  Charles replied 8 months ago.

What was the fuel pressure when you tested it?

Customer: replied 8 months ago.
Mine is also a 2 pin there are 3 signal wires one to each injector I checked each one individually while engine would not start I checked my method while engine was running to verify signal with noid light on each injector
Customer: replied 8 months ago.
i switched control module one time while engine would not start and immediately gained injection pulse and engine started ran for awhile and cut off with same problem
Customer: replied 8 months ago.
Don't recall off the top of my head have it written down somewhere but I started there at the beginning of all of this before I got to this point and pressure was always good tested several times again just to monitor
Customer: replied 8 months ago.
Won't allow me to use your link as a guest to log in to verify part 28 Mercury schematic just call it control module has 3 plugs and a ground
Customer: replied 8 months ago.
That works yes part 28
Expert:  Charles replied 8 months ago.

Ok, so it ran for a few after changing that? Did the doner engine run when the part was replaced back on it?

Customer: replied 8 months ago.
Didn't have a doner engine marine friend of mine had another new one on shelf he let me try same results actually set a bag of ice on controller once and it started just so you no engine temp never exceeded 170 under load in test tank mostly stayed 150 to 165
Expert:  Charles replied 8 months ago.

Does the alarm on the engine beep when you turn the key to the ON position?

Customer: replied 8 months ago.
alarm system is in working order
Expert:  Charles replied 8 months ago.

Great. Your question says that you have already replaced the trigger, is that correct? If so, was the replacement new or used?

Customer: replied 8 months ago.
It was a new part
Expert:  Charles replied 8 months ago.

Ok,

How long ago was that?

What did CDI say about the ECU? Was the Fuel injector driver bad?

Customer: replied 8 months ago.
Trigger coil was the last part I replaced during this process cdi could not tell me what they replaced only that it was tested before I got it back i have been looking for used ecm to try but this one is not very common
Expert:  Charles replied 8 months ago.

How have you been searching? That ECU was used for some time

Customer: replied 8 months ago.
Internet and local ,have to run for now will get back with you later today thanks for responses
Expert:  Charles replied 8 months ago.

Your welcome.

Where are you located in the USA? i am in AR. I have a day job in a repair shop and will come back online after 6PM CST tomorrow. Talk to you then.

Customer: replied 8 months ago.
Ok Charles back online
Expert:  Charles replied 8 months ago.

Me too

Customer: replied 8 months ago.
Have any new thoughts on my problem
Expert:  Charles replied 8 months ago.

Where are you located?

Customer: replied 8 months ago.
Maryland
Expert:  Charles replied 8 months ago.

Ok, thats a bit far.

Customer: replied 8 months ago.
I'm on east coast quite far away from you
Expert:  Charles replied 8 months ago.

Rereading our responses, W

When you tested with the noid light, were you plugged into the harness from the engine, or the one going to the injectors?

Customer: replied 8 months ago.
Back probed while connected and functioning
Expert:  Charles replied 8 months ago.

What color of wire did you use as the hot wire? There are 4 wires there.

Customer: replied 8 months ago.
I believe 12volt power in that plug was red trying to find schematic that I documented what I did now
Expert:  Charles replied 8 months ago.

The red is the hot wire. The ECU controls the ground through the other colors.

Do you have a multimeter?

Customer: replied 8 months ago.
Expert:  Charles replied 8 months ago.

Disconnect the plug to the injectors, then using the meter, test the resistance between the red and the other colors going to the injectors. What do you get for the resistance on each?

Customer: replied 8 months ago.
1.1-1.0 on all 3
Expert:  Charles replied 8 months ago.

Ok, they are all good.

When the engine will not start, do the gauges still work?

Customer: replied 8 months ago.
I checked voltage at engine it was good
Expert:  Charles replied 8 months ago.

On the purple wire? Not a red?

Customer: replied 8 months ago.
Just general voltage at solenoid
Expert:  Charles replied 8 months ago.

Ok, Can you run the boat, make it fail, and when it will not restart, check the voltage on the back of the tach on the purple wire to the black wire, without touching the key first?

Customer: replied 8 months ago.
What should it be
Expert:  Charles replied 8 months ago.

Battery voltage on the purple when the key is in the on position, but I dont want you to turn the key off when the engine dies, leave it on, and test the voltage first.

Customer: replied 8 months ago.
I'm talking to my buddy that has test tank tomorrow I was going to ask him then when I can use it again won't be this weekend I am going out of town,trying to get as much info and things to try before I get there to run this thing
Expert:  Charles replied 8 months ago.

I would try that, and if you are losing power to the purple wire, replace the key switch or test for power on the back of it as well before turning the key off.

Customer: replied 8 months ago.
I can start with that have not checked anything like that yet
Expert:  Charles replied 8 months ago.

This is a really odd issue. I have not seen something like this in the field in 11yrs. But it could be just a key switch causing the problem.

Customer: replied 8 months ago.
I no I have stumped several people with this problem even people who work on these everyday / I feel it is something simple I am just not seeing engine has been extremely trouble free for years until it sat
Customer: replied 8 months ago.
It will probably be a week or two before I get an opportunity to test again as soon as I do will let you no results / if you think of anything in the mean time please let me no. thanks again
Customer: replied 8 months ago.
Also temperature seem to agrevate problem. / the hotter it is outside the easier it is to get the problem to occur
Expert:  Charles replied 8 months ago.

Ok, try two tests. One with the temp senders plugged in and another with them unplugged. You may have a bad sender.

If you know someone with a scanner, you would need to have it hooked to the engine during the test as this ECU does not store codes once the key it turned off.

I do work in these everyday. That is my day job, I only do the online thing at night and on the weekends.

Customer: replied 8 months ago.
Ok the guy with the tank has a scanner I will try that as well and will let you no results as soon as I test thanks for the help
Expert:  Charles replied 8 months ago.

Your very welcome. If you do so on a Sat. After you reply to me, if you want to switch to the phone, simply accept the offer that I have sent to you.

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