1997 Merc. 150 EFI Help

Greensleeves · May 11, 2010

Hello all, I'm new to the forum and I need some help with my engine. I have a 150 efi and it was sitting for about 6 years, I just put it on my boat and I can't get it to run. I changed the fuel filter and drained the diaphragm, pumped her up and it will only run for a few seconds then bog out like its starving for fuel. The fuel pump in the diaphragm pulsates but I'm not sure if that's how its supposed to be??? I also have an external oil tank on order I don't have the old one, so I blocked off the two lines and filled the tank under the cowl, do you think blocking off those lines would cause it not to stay running??? I really appreciate any input you guys have to offer.

Barnacle_Bill · May 11, 2010

Re: 1997 Merc. 150 EFI Help

http://forums.iboats.com/showthread.php?t=158086

Greensleeves · May 11, 2010

Re: 1997 Merc. 150 EFI Help

Thanks, That had some helpful hints. I have a repair manual on order but I'm thinking I should get a real one from mrec. I did almost everything from that link but I am worried about it not getting fuel. I think I should take the diaphragm apart and clean it out what do you guys think?

CharlieB · May 11, 2010

Re: 1997 Merc. 150 EFI Help

The low pressure pulse pump fills the vapor seperator that contains that feeds the high pressure pump.

Remove the spark plugs and ground all the spark plug wires.

Remove the fuel line from the discharge side of the low pressure pump, point it into a suitable container.

Crank the motor and observe the pulsed fuel stream from the pump, is it a strong pulsed flow? If any doubt, rebuild the pump.

If the motor continues to die, attach a fuel pressure guage (at least a 60 psi guage) to the fuel rail and observe fuel pressure when cranking, running and while it dies. Does it remain steady? If the high speed pump is failing OR if the float valve in the vapor separator is sticking, the pump will run out of fuel.

Clean the vapor separator.

Greensleeves · May 12, 2010

Re: 1997 Merc. 150 EFI Help

Is it safe to use carb cleaner in the vapor separator?

CharlieB · May 12, 2010

Re: 1997 Merc. 150 EFI Help

Spray cleaner such as Wal-Mart Super Tech Carb Cleaner works great.

I would be leery of using a soak such as Berrymans.

Greensleeves · May 12, 2010

Re: 1997 Merc. 150 EFI Help

I cleaned out the vapor separator and put it all together pumped it up and now it doesn't even want to start. do I need to prime the system somehow? What do you mean by ground the plug wires? Cant I just pull the emergency tether and crank it that way? Thanks, Bryan

CharlieB · May 12, 2010

Re: 1997 Merc. 150 EFI Help

Pulling the tether will kill the ignition OK.

Cranking without the spark plugs is easier on the starter and battery.

When you first turn the key ON the high pressure fuel pump should come on for 2 seconds to bring fuel pressure up in the fuel rail to the injectors.

Once you start cranking the pump should come on again.

The fuel pump is constantly supplied 12 V, the computer controls the ground side to switch the pump on and off.

Pumping the primer bulb should fill the vapor separator, then once the key is first turn on the system should prime and charge the fuel rail.

You can check for fuel pressure in the rail, but be very careful, it is under pressure and WILL spray out. There is a fitting that looks sort of like a tire air valve (Scrader Valve) remove the cap and momentarily depress the pin, WATCH OUT for fuel spraying, no smoking, no sparks, etc. Wear safety glasses.

If no fuel pressure then use a test light and make sure there is power to the fuel pump, on BOTH sides, as there is NO ground until the computer grounds it, you should read voltage to, and through the pump, if not, there is a problem with the pump. Can you hear or feel the pump run when the key is first turned ON.

Greensleeves · May 12, 2010

Re: 1997 Merc. 150 EFI Help

I tested the pump for voltage and it was correct, like you said it had voltage on both sides. I can hear the pump in the separator pulsate when I turn the key on, I will try to see if I get fuel out of that port tomorrow. I'm a little concerned why it doesn't start now really weird, it doesn't even want to start. I pulled the plugs today and they were wet with a brown fuel mix, dirty injectors???? Maybe I should get new plugs as well.

Greensleeves · May 13, 2010

Re: 1997 Merc. 150 EFI Help

I took the line off the pump in the vapor separator, and I have no fuel there even when I crank it nothing. I depressed the pin in the valve and not a drop of fuel came out. I'm guessing I need to rebuild the pump in the vapor separator???

Greensleeves · May 13, 2010

Re: 1997 Merc. 150 EFI Help

Anyone know a place to get a pump or even a rebuilt one? The local marina wants $650 for a new one. I have no idea how to rebuild mine unless they sell a rebuild kit. I did some calling around and no one in my area will rebuild it. Any help will be greatly appreciated.
Thanks, Bryan

CharlieB · May 13, 2010

Re: 1997 Merc. 150 EFI Help

Before spending a lot of money on a new pump, check to be sure that the vapor separator is filling from the primer bulb and pulse pump, then see if you can disconnect the outlet from the high press pump, trigger the pump with the key and see if it will prime.

Greensleeves · May 13, 2010

Re: 1997 Merc. 150 EFI Help

The vapor separator is full, I pumped the bulb and it filled it. I took the line off the pump on the vapor separator and I get nothing from it. Should I take the line off that exits the diaphragm and fuel water separator and then feeds the vapor separator? I may be a bit confused on which pump might be bad, maybe both??? Sorry for my ignorance on this I don't have a manual yet

Faztbullet · May 13, 2010

Re: 1997 Merc. 150 EFI Help

Disconnect the wires from ECU to fuel pump and apply a 12 volt source to pump(watch polarity), if it runs the driver board in ECU is faulty..

CharlieB · May 14, 2010

Re: 1997 Merc. 150 EFI Help

Faztbullet is telling you to disconnect both wires from the fuel pump, use your test light on the disconnected wires to identify which side is positive.

Rig a jumper wire from the battery or the hot side of the starter relay to the + side of the pump.

Rig a good ground wire to the other side of the pump.

Does the pump now run and pump fuel?

Doing this with jumpers will not harm the ECU and should determine if the fault is the pump or the pump driver inside the ECU box.

Greensleeves · May 14, 2010

Re: 1997 Merc. 150 EFI Help

I tested the pump like you said and its definitely frozen. I'm gonna take the vapor separator apart tomorrow and take the pickup off the pump and spray some mercury power tune engine cleaner inside it. I'll try to free the pump up with that stuff and hopefully I can get it unstuck. The cheapest pump kit that I could find so far was $550 so I'm keeping my fingers crossed. Thanks for the input I'll keep you guys posted.
Thanks, Bryan

Faztbullet · May 15, 2010

Re: 1997 Merc. 150 EFI Help

Call promarine @800-621-7761 part #8090

Greensleeves · May 15, 2010

Re: 1997 Merc. 150 EFI Help

Thanks I will give them a call Monday, it sucks because the part is NLA that's why its so expensive. I've been spraying that cleaner in it all day with no luck. I'm gonna keep it soaking, but I think I'm gonna get a new one. I would hate for it to lock up on one of my Canada trips, I cant imagine what I would pay for one there.

CharlieB · May 17, 2010

Re: 1997 Merc. 150 EFI Help

The pump is a vane pump, tight clearances may not allow the cleaner to penetrate.

Try filling the pump from the discharge side then using jumper leads. NOT the computer wiring, 'shock' the motor backwards a couple of times t get just that half a degree of rotation in the pump.

Shock it forwards then backwards a couple of times, each time it should work to get the cleaner farther into the vanes and slots of the pump, it will come free and work fine for years.

Stow the new pump and take it along, chances are you won't need it for a long time.

It is common in refrigeration to use a repeated reverse shock to free a stuck compressor, same thing, only different.

CharlieB · May 17, 2010

Re: 1997 Merc. 150 EFI Help

Pump Trivia (History)?

Vickers used a similar vane pump design but much larger as a hydralic pump on Caterpiller Equipment, the pump design was capable of outputs of 1800 to 2400 psi at 45 Gph

Bosch reduced the size and first used an all stainless pump section in their first product fuel injected VW in 1969, the pump was capable of over 100 psi and flowed enough fuel it was also used on turbo charged models for the German Police use.

GM, Merc, Chrysler, and Ford, all use a design similar to the Bosh pump, all stainless pump section. Any other metals would react to the water contained in the alcohol of our fuels today.

Your vanes are stuck from the fuel/oil residues left from drying out, sitting for such a long time.

It will take a while for chemical to penetrate and loosen the gum/varnish that has the vanes stuck, but if it were possible to disassemble the pump for inspection I would be willing to bet that you would see NO physical damage to the vanes, rotor, or body.

Be patient.

1997 Merc. 150 EFI Help

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