1990 OMC Cobra Stalls(4.3L)

[dogboy7301]

I took boat out of storage and put gas in it. It would not start for nothing. Would turn over but no start. Replaced spark plugs, fuel filter, changed oil and filter. Finally it starts. Took boat to lake for test run. It ran fine for bout 3 minutes then stalled(Didn't die). I let off the throttle, then gave it gas. Ran fine for bout 3 minutes again then did the same thing. Checked all fuel lines, non were clogged. Tried removing the fuel pickup tube(no luck). Couldn't get it out. But, i was able to remove the sender unit and see the screen at the end of the tube. Doesn't look clogged. Started reading the manual and it said that the fuel pump is fitted with a transparent over flow hose and that it shouldn't have any oil or fuel in it(IT DOES). If so, it said that the pump diaphragm has ruptured and the pump should be replaced immediately. Just wanted to know if this was true and can this cause the issues I'm having with motor stalling.

 

[Don S]

Re: 1990 OMC Cobra Stalls(4.3L)

Started reading the manual and it said that the fuel pump is fitted with a transparent over flow hose and that it shouldn't have any oil or fuel in it. If so, it said that the pump diaphragm has ruptured and the pump should be replaced immediately. Just wanted to know if this was true and can this cause the issues I'm having with motor stalling

Nah, they just put that in the book to sell fuel pumps........................

OF COURSE IT"S TRUE, why do you think they put it there. Yes it will make is stall, because it's flooding the engine with excess fuel.

 

[bruceb58]

Re: 1990 OMC Cobra Stalls(4.3L)

If that tube has fuel in there it means the pump diagram is broken and could easily be the cause of your problems.

 

[dogboy7301]

Re: 1990 OMC Cobra Stalls(4.3L)

Ok Thanks!!!!! Next question! Never replaced fuel pump before. I know there's only 2 screws connecting it to the motor. Is there anything I should know before I replace this and do u know the price for a new fuel pump. I like doing things myself(saves me money).

 

[dogboy7301]

Re: 1990 OMC Cobra Stalls(4.3L)

Replaced fuel filter, fuel pump, spark plugs. Still stalls at high rpm's. Could it be something with the distributor? Also, now it when under load, I put it in forward it sputters. I can keep going back to neutral and finally it takes off. This happens when I go to reverse also.

 

[sea wolf]

Re: 1990 OMC Cobra Stalls(4.3L)

What do u mean, "it takes off" in neutral. Did u mess with the carb? When's the last time u adjusted the shift cable?

 

[dogboy7301]

Re: 1990 OMC Cobra Stalls(4.3L)

I can keep going back and forth from forward to neutral and finally it will take off without sputtering. But then when I get up to high rpm's, it stalls. Go back to neutral, play with it again(forward to neutral). Takes off and stalls again at high rpm's. I had the shift cable replaced bout two years ago. So, I would say bout two years ago it was adjusted.

 

[Juniinc]

Re: 1990 OMC Cobra Stalls(4.3L)

I got the same set up,,,OMC 4.3.
same problem when I picked her up.
changed the fuel pump but didn't help
ended up removing the tank,,,

My case was water in gas, a clogged vent hose, a faulty check ball in the pick up line fitting.
I replaced the fitting, drained bad gas, dried the tank for a few day,,,
now she purrs like a kitten.

 

[HT32BSX115]

Re: 1990 OMC Cobra Stalls(4.3L)

I got the same set up,,,OMC 4.3.
same problem when I picked her up.
changed the fuel pump but didn't help
ended up removing the tank,,,

My case was water in gas, a clogged vent hose, a faulty check ball in the pick up line fitting.
I replaced the fitting, drained bad gas, dried the tank for a few day,,,
now she purrs like a kitten.

Good job!!



Don't you just Love it when a plan comes together?

 

[dogboy7301]

Re: 1990 OMC Cobra Stalls(4.3L)

So, how did u know the check ball was faulty? I've already drained the tank once.

 

[starsnstripers]

Re: 1990 OMC Cobra Stalls(4.3L)

You said you replaced the fuel filter, was it the water seperater canister spin on filter? If so there is a small fillter where the fuel line goes into the carb. Take the line off and unscrew the big nut it's like 1" on the carb. The symptoms tell me thats dirty and needs changing. good luck.

 

[starsnstripers]

Re: 1990 OMC Cobra Stalls(4.3L)

It's slowly filling up the carb bowl but when you give her the gas it uses it faster than the filter can feed it! Been there!

 

[dogboy7301]

Re: 1990 OMC Cobra Stalls(4.3L)

yes it was the water seperater canister spin on filter. U say this small fillter where the fuel line goes into the carb. Is it between the pump and the carb. If so, there isn't one. There is a inlet line coming from the tank to fuel filter then a line goes to the fuel pump and then to the carb. There isn't any small filters anywhere. Will it be on the inside of the 1" nut?

 

[starsnstripers]

Re: 1990 OMC Cobra Stalls(4.3L)

Yep

 

[starsnstripers]

Re: 1990 OMC Cobra Stalls(4.3L)

Here's a pic of it

 

[starsnstripers]

Re: 1990 OMC Cobra Stalls(4.3L)

Behind this fitting.

 

[dogboy7301]

Re: 1990 OMC Cobra Stalls(4.3L)

Ok thanks!!!! I'll check it tomorrow and let u know what I find.

 

[starsnstripers]

Re: 1990 OMC Cobra Stalls(4.3L)

Easy fix for a couple bucks! haha

 

[starsnstripers]

Re: 1990 OMC Cobra Stalls(4.3L)

Oh it's there and is getting clogged. be careful taking it off there is a thin washer behind the nut and a spring behind the filter, dont loose em. good luck, should purr like a kitty after.

 

[dogboy7301]

Re: 1990 OMC Cobra Stalls(4.3L)

k i will be careful taking it off. Hope it does the job. Would love to hear that kitty purring right about now.