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1996 mercury efi 200 hp bogs after warm up

G

Going broke

New member
Need some help my 200hp when cold will start and idle great and will top out great after a few min it will idle different and will not get on plane I can hold it to the floor and it may go a min or 20 min then it will pick up and go sometimes it will cut out again it's very sporadic


took it it to a local guy I've known for years and ran some tests
good compression
good fire
tps right
new fuel filter and line
rebuilt low pressure pump
stador was bad replaced it
cleaned out the vct
and he checked the ecu
new water separator it did have water and bad fuel in it
new plugs


had it at a different shop to put new carpet in it and they where supposed to service the motor
plugs
filter
lower unit oil
they said they had to clean the injectors to get it started but they didn't put new plugs and lower unit oil or a new water separator
 
Took it out today and hooked a meter up the the cylinders and got it to act up and it was still firing the same on all cylinders I don't know where to go from here
 
Going broke said:
Took it out today and hooked a meter up the the cylinders and got it to act up and it was still firing the same on all cylinders I don't know where to go from here
Click to expand...

Sounds like classic failing stator to me. Most electrical faults will show their faces when warm/hot engines. Have you checked voltage at the battery, is it charging?

you say meter to cylinders what meter, a timing light? Sometimes a timing light will still flash even if there isn't enough spark making it to fire the cylinder.

do you know how to index the flywheel? What you do is mark TDC for each cylinder on the top of the flywheel, then when the motor is running you should only see the proper cylinder firing when the timing light is on the corresponding cylinder.

you need to hook a dva adapter to your colt meter
and check the dva of each leg off the stator to try and isolate the fault.
 
Sorry I just saw that you replaced the stator already. A stator will take out your voltage regulator sometimes causing erratic behavior on these efi's
 
The volt meter on the dash moves I was told it the regulator is out it will not move ..... the tester we hooked to the boat hooked to each coil and had a 6 position switch so we could isolate each cylinder and the voltage was around the same on each one I will check fuel pressure and see what it does
 
36-39 is right on spec for that engine. You need to put a gauge on it and take it to the water. Then have someone check the gauge WHEN the problem is happening. Sometimes the high speed fuel pump will start to fail intermittently. You can also check the resistance of the fuel pump and see if it is in spec.

Cleaning the injectors is never a bad idea, but I dont think FLOW is your issue since it is so intermittent. Could be the "gates" in the injectors, but a simple resistance test when warm could isolate that issue.

Since it is happening when it is warm I am pointing my finger straight at electrical, which also may mean electric fuel pump.
 
Send injectors and ECU to Brucatosv.com and have tested...sound like MAP sensor could be failing. Check that the MAP hose is not full of fuel when this happens.
 
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