I have a MEP-016E that turns over and won't start. The electric fuel pump and the solenoid that controls the throttle will only work very intermittently. Since the machine was converter to the yanmar engine, it doesn't appear to have worked because the oil in it is golden clear like it was poured in 30 seconds ago. Fuel tank is full and the floats seem to be working. The engine will run off starter fluid and I can unplug the fuel pump and touch the connector to the battery and pump will start clicking which I guess means it's pumping. I have checked the connectors to make sure there is no loose connections and have not found any.
If unable to find the short, can you straight wire the fuel pump and throttle solenoid?
Any help or suggestions greatly appreciated.
Q
I'm just getting up to speed on one of these myself. But I have been around the B which the E came from.
For test purposes you may hard wire the pump and the solenoid, no problem.
Or just pull the solenoid back and tie wrap it to something. cut the tie to shutdown.
If the fuel system is tight and the pump is tight it will stop when it makes pressure on its own. It is nothing more than a hollow solenoid plunger with check balls in it and a spring to allow it to push fuel. When the fuel pressure rises and meets the spring pressure the plunger stops moving. So it is not necessarily a problem if the fuel pump starts and quits, as long as the fuel pressure is up.
However, the solenoid must remain energized any time the master switch is in the aux run or run position.
Given the fact that both are behaving the same at the same time would lead me to think the problem is upstream in the electrical system. The unit tank pump is down low under the fuel filter and it has its own relay. The relay for the fuel solenoid is in the control box on the left side board. So, again if both are acting up at the same time then only the master switch is upstream of that. If it won't crank when it drops the solenoid then I would look at the ground or the master switch feed because the crank signal uses a 3rd relay also mounted on the board (followed by another solenoid on the back of the control box). If it does not crank when the fuel solenoid drops then either the ground is bad or the feed to the master switch is bad. If it does crank when the fuel solenoid drops out then I would suspect the master switch or any common output wire from the master switch to the control board. Sometines contact cleaner will help the switch.
Something that has helped me a few times, and I did have one with an intermittant fuel solenoid, is to power it up and shake all of the wiring you can get a hold of a piece at a time while observing if the solenoid starts clacking on and off. This led me to find a bad crimp connection within the solenoid plug on the harness at the solenoid. (after I burned time inspecting all the relays and tank floats and such!) I should have begun with the easiest procedure first!
In all likelyhood it is just a loose connection somewhere and will be a breeze when you discover it.
BTW if you do suspect a bad relay on the leftside control board, they are 8 pin reversible and interchangable relays and will work installed either side up. Pull the suspect one out and flip it over or swap it around and re-install it to see if there is any change. They don't fail much, though.
Good luck and please post what you find!