6BT5.9M210 Fails to Start

[Orin Guidry]

1989 6BT5.9M210. CPL 0742. Fuel pump Lucas CAV DPA.

Engine has never failed to start. Small fuel leak two months ago, thought to be from the solenoid. It is difficult to see pump, outside of port engine in tight engine room. Very respected local fuel pump shop rebuilt and reinstalled pump. Ran great. Two weeks later ran great again in slip. On Saturday engine started for a few minutes before guests arrived and then shut down. When guests arrived, the engine failed to start. Turns over vigorously but never starts at all. Fuel squirts out the two bleed points on the fuel pump when the lift pump lever is pumped. I cracked all the injectors and saw fuel but I have never done this before so don´t know if it was enough.

I will be getting the pump shop out again but wondered if the wisdom of the group had any thoughts.

Is it possible that on stopping the engine, that the stop solenoid gets stuck in the stopped position?

1 user thanked author for this post.

sunlprince91

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[Bruce Poole]

Was the sylinoid your problem? We are having the same issue. Fuel pump is full of fuel but nothing coming to injectors

[Orin Guidry]

The end of the story and thank you for the previous helpful comments.

Fuel pump was perfect on the test stand twice. New fuel lift (transfer pump) installed. New solenoid and adequate voltage to the solenoid. Injectors pulled and all good. Good compression in all cylinders.

The fuel return line on this boat is in two parts – blue flexible hose connected to the engine and copper tubing connected to a manifold that directs the flow to the tanks. Mechanic cracked the connection between the hose and the tubing and the fuel was under pressure. Put the hose in a bucket and the engine instantly started.

The fuel return line is now new hose from the engine to the manifold and the engine has promptly started on a number of occasions.

Apparently this engine has a Tee in the fuel return line that returns a portion of the fuel to the tank and a portion is returned to the fuel pump. An obstruction in the fuel return line results in high pressure in the pump and stops its flow.

Quite an education!

[Orin Guidry]

I have not installed the bulb. The failure to start began after the fuel pump shop rebuilt the pump to correct a leak. I am letting the fuel pump shop sort out this problem and correct it. I appreciate the advice and may install the bulb once they get it up and running.

[Tony Athens]

#1—————-This pump is tough to bleed……..Did you install a “squeeze bulb” and do as I said?

Tony

[Orin Guidry]

Mechanic returned and replaced solenoid. Engine again failed to start and no fuel coming out of injector lines. Old solenoid tested and found to be functional. Pump removed and back to fuel pump shop.

[Tony Athens]

Keep us in the loop…

I do not have a pic of the “tool” , but I know I took a cheap 12 point 15/16’s box end wrench and whacked it off so it’s about 5″ long, total to get to FIT….Perfect tool to for the “tool bag”……………………..

Tony

[Orin Guidry]

A little more information. Mechanic finally came out. There is adequate voltage to the solenoid. Pump is full of fuel but nothing at injectors.

Either bad solenoid or a problem in the pump. Next step is to replace solenoid.

The solenoid is hard to access on an engine that is even harder to access.

Mechanic left to craft a wrench that he feels will make replacing the solenoid easier.

[Philip]

Short answer is yes.

Somewhere you have a dirty or otherwise bad connection or wire that is causing voltage drop. Maybe that’s your problem, maybe not but for sure you need to spend some time disconnecting EVERY connection one by one, cleaning with emery cloth, tooth brush, WD-40 (or solvent/cleaner/grease of choice), and reconnecting solidly. That may solve your issue….

[Orin Guidry]

More information. Engines are in a Grand Banks and is likely a non standard installation. I have attached a picture of an Omran brand relay that has four wires going into it. The red on the right is from the harness and is always energized when the POWER breaker for that engine is on. The red wire on the left goes to the fuel pump solenoid and is energized when the POWER breaker is on and the voltage goes to zero when the STOP button is pushed. The green wire is at 0 volts and is energized when the STOP button is pushed.

So I am assuming that this arrangement is that the solenoid is energized to run. The STOP button the relay cut off current to the solenoid stopping the engine by energizing the green wire.

So here is my new question. When the POWER breaker is on for the down engine, both red wires read 11.4 volts.

Is low voltage to an energized to run solenoid a reason for failure to start?

The voltage at the harness connection is 12.7. What could cause a downstream wire to be 1.5 volts less?

Thanks

[Tony Athens]

I would do two things if I had 6BT 210’s..

1) Learn where the solenoid is on the engine that is easy to get to.. Then turn on the key– Remove the wire that goes to the solenoid and touch it to the terminal a few times– You should hear a “click” each time.. That connection of the wire to that terminal has always been a weak point.. Now test the other side.

2) That engine is a pain in the butt to bleed– With said, buy 2 x 3/8″ good quality outboard type squeeze bulbs.. Find a convenient spot right near the engine, cut the fuel line and install where they are easy to get to.. That will solve your bleeding issues–superior to the on-engine lift pump.. That engine is such low flow, you DO NOT have to put them on a bypass valve arrangement… If you have a second person, give the engine 100% throttle, and squeeze away when the engine is cranking–It will just about always “bleed thru all the way” to the injectors

Report back..

Tony

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