4.3 - Engine won't shut off

[JagGuy]

Hello Everyone

I just got my engine dying problem fixed (http://forums.iboats.com/showthread.php?t=505215&highlight=4.3+Dies+WOT+-+fine )
and when I went to turn the engine off, nothing happened. The engine kept running and the only
thing I noticed was the voltmeter would swing between 9 and 13.5 volts. That stopped when I
turned the ignition to "run" and started again when I turned it off.

Also, when the ignition is turned on, the fuel pump starts which to my understanding, should not
happen. It's supposed to work only when the alternator is spinning.

Other than installing the new fuel pump, I tried to remember what I had done that could have made
the engine not shut off.

I had done three things:

1 - I disconnected the tach. I don't see how this would effect anything, but I connected it
once again, started the engine and it still wouldn't turn off, so it's not the tach.

2 - The new distributor had instructions to remove the resistor that goes from the pump
relay to the coil. Apparently, the electronic module in the distributor needs full battery voltage
and the resistor lowers it. The resistor is in the purple wire with some connectors and was easily
removed without any tools or splicing etc. Once again, I don't see how this effects anything BUT
this purple wire does go all the way to the ignition switch.

I did not put the resistor back and try to stop the engine. It's not supposed to have the resistor in
place, so I am reluctant to do this.

3 - I removed the connectors on the two relays and inadvertently swapped them. I think they are
both the same since the part numbers on them are identical, but the relay schematic is different on
each one, but I think that's just because the paint is worn in the diagram. I included pics of the relays.

>>> Are both relays the same?

>>> Does anyone know the part numbers to get a replacement?
The numbers on the relay don't match anything online.

I swapped the relays back, started the engine and it wouldn't shut off.

I know this is a little complicated, but I wanted to include everything I did.

I have this one remaining problem, and I really hope someone can help.


Thanks . . . Brian

 

[Raystownboater]

Re: 4.3 - Engine won't shut off

In your original post, you added a pigtail to your fuel pump.......did you forget to remove it?

 

[Raystownboater]

Re: 4.3 - Engine won't shut off

With your key in the "off" position, check the + side of the coil with a test light or meter. There shouldnt be any voltage there but if there is, that would cause the engine to continue running after the key is turned off.

 

[stackz]

Re: 4.3 - Engine won't shut off

well, how exactly have you been shutting it off...when it wouldnt turn off?

at this point, I'd be using a 60amp toggle just due to coil voltages to cut coil voltage to shut it off while you test this problem.

though, I'd start looking into the fuel pump wiring as the issue originated there.

maybe there's a floating ground or 12v+ source that was undetected earlier on which ended up frying the original fuel pump....and now that you have a new fuel pump...it cant shut off properly until that new fuel pump fries.

I'd try to source the factory wiring diagrams and start testing wires looking for false grounds, bad grounds, cross connects, etc.

I've learned with boats that regardless of the Previous owner saying it was fresh water....it likely had salt water exposure during a family trip or was left outside for some stupid reason, etc.

just dont trust people....trust your ohm meter/multimeter....

 

[JagGuy]

Re: 4.3 - Engine won't shut off

Hi Guys

Thanks for the replies.

Yes, the pigtail is gone and the original wiring hooked back up.

I stalled the engine by just turning the carb idle screw.

You're right that maybe the old pump fried because it was on
all the time?

I will look for battery voltage at the coil, but I am fairly certain
it's going to be there, otherwise there would be no power to the
coil. The ignition switch should turn the purple wire going to the
coil - off.

I still think somehow it's something I touched (tach, relays or
the resistor)

It could be a bad ignition switch too I suppose.

I'm wondering if the pump relay fails in the closed position (like
it was "on" all the time) would that cause this problem?

There must be a procedure to test the relays?

What a problem to have !!

Thanks . . . Brian

 

[Raystownboater]

Re: 4.3 - Engine won't shut off

Hi Guys

Thanks for the replies.

Yes, the pigtail is gone and the original wiring hooked back up.

I stalled the engine by just turning the carb idle screw.

You're right that maybe the old pump fried because it was on
all the time?

I will look for battery voltage at the coil, but I am fairly certain
it's going to be there, otherwise there would be no power to the
coil. The ignition switch should turn the purple wire going to the
coil - off.

I still think somehow it's something I touched (tach, relays or
the resistor)

It could be a bad ignition switch too I suppose.

I'm wondering if the pump relay fails in the closed position (like
it was "on" all the time) would that cause this problem?

There must be a procedure to test the relays?

What a problem to have !!

Thanks . . . Brian

I'm pretty certain there is voltage at the coil also. If its there when the key is turned off, chances are that's your problem.

 

[stackz]

Re: 4.3 - Engine won't shut off

I'm pretty certain there is voltage at the coil also. If its there when the key is turned off, chances are that's your problem.

thats what I meant. kinda hard typing what all I want when I'm on my droid phone lol.

but yeah, with the key off, you should not be getting power to the coil. if you are its time to trace the circuit from the coil wire and see where the issue is occuring.

my main thing with this is it sounds like something is seriously wrong with the main power circuit as this engine not only has coil power but also has a 12v powered fuel pump....which if the issue was only affecting the coil, the engine would shut off when the key was off as the fuel pump would not be getting power and the engine would just run out of gas after a couple minutes since even though the coil is getting voltage...the pump would be off.

how long are you letting it run after you cut the key off before you choke it down? depending on the size bowl the carb has and the amount of pressure the electric fuel pump creates, the engine could run for a good bit before it drains the carb and the fuel pressure is relieved at idle.

have you checked to see if you are getting power to the fuel pump as well as the coil after the key is off?

 

[0352Marine]

Re: 4.3 - Engine won't shut off

What about your kill button in the engine compartment? With the engine running you should be able to push the red button and kill the engine does this work? Also your pigtail should have been jumped between 87 and 30 was this done? When you jumped the relay with the pigtail did you remove the relay? Also at the switch with it in the off position test the ignition wire see if it has power it could very well be a bad switch.