Logo
FULL SITE MENU

Check Engine light & beep

K

Kennon

New member
1999 Johnson 200 HP Just bought, seller said model is Looper. Seller was working on a problem when I arrived. Said it was fuel line problem. He had friend - retired marine mechanic working on it. Told him if problem fixed I would buy. Came back when he said it was fixed for sea trial. Boat ran perfect, so made deal. Came back next day to take it to the lift I rented. On way home @4000-4500 RPM, Check Engine light & beep came on so I stopped to idle, light & beep went off. Check Engine light, Low Oil light, No Oil light, Water Temperature light all in one gage. Started again to 4000, CE light & beep on again. Seller said very little gas in tank, so put 40 gal 90 Rec & filled oil tank. Same thing @4000...CE light & buzzer on. Motor runs great, no sputter, water stream out 3 feet, motor completely still, no shaking, no skip...nothing but CE light & beep. I called seller, said positive it was fuel line, but engine ran smooth as silk. I understand CE checks other than fuel line... maybe something in VRO. I spent all money for boat, so have to be fairly certain I know what the problem is when I hire local mechanic.
 
That is what the seller said until everything (all fittings and filters (2) were replaced). I certainly am NOT a mechanic, but the logic doesn't fit for me: Engine runs perfectly at all speeds, how could a fuel line issue allow this? No smell, visible signs in boat bottom.

P.S. Used to live in Fair Lawn - Bergen County
 
Last edited:
^^^^^^

Probably why he carries a big bilge pump.

As said above, the sensor is detecting an unusually high suction (vacuum) in the incoming fuel line from the tank.
Can be the primer bulb, the fuel pickup in the tank, kinked hose, anything that would restrict the fuel flow to the engine.
The sensor in question is mounted right beside the fuel pump, on the same bracket.
It has 2 wires going to it, and a rubber hose that is tee'd into the incoming fuel line to the pump.

I would almost suspect, since you say it runs perfectly, that the sensor might be faulty.
The only way to be sure, is to tee in a vacuum gauge, and read the exact suction (vacuum) in the incoming fuel line.

I think, from memory, the spec is 7 mm Hg when the switch trips.
 
The vacuum gauge shouldn't go above 4 in. Hg. You can check the sender with a vacuum pump and an ohmmeter.
 
Chris,
This now makes perfect sense to me. Thank you so much, I would never ever have thought of that. I'm certainly glad I found this site, with a 15 year old engine and living on Social Security, you know I'll be back.
Sincerely, Kennon
 
Last edited:
Back
Top