1990 OMC Cobra 4.3L V6 Mod# 432APRRGD Fuel and electrical problems/questions

Skyrivers

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1990 OMC Cobra 4.3L V6 Mod# 432APRRGD Fuel and electrical problems/questions

I picked up a 1991 Hurricane deck boat. It has the OMC engine listed above. I am not getting fuel to the carb and have some questions.

1) First observation is that the float on the carb is not moving but is not stuck. I know is electronic. Looks like a holly 2 barrel that came with the engine originally. What should the voltage be across the solenoid to actuate it?

2) Would love a wiring diagram that shows how the battery and engine should be wired to all the solenoids for it. Is there a repair manual available I can purchase somewhere that will give me this information? Just want to make sure everything is wired up.

3) I know the fuel pump is mechanical in nature. I think the part number is 982997???? Other than disconnecting the fuel line is there any other way to check it? I did replace the fuel filter to eliminate it from the problem. All the lines and hoses look good. Just no fuel?

4) I tried to start the engine by pouring some fuel down the carb but did not even try to crank up. Everything is turning as it should and plugs getting spark but not even a sputter from the fuel I gave it manually. Would the electronic part is the carb effect this? Can their be a problem with the ignition switch that might cause this? How to check both?

Thanks for taking the time to help.

Sky
 

Lou C

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The carb is not electronic. What you are looking at is an electrically heated choke. There are OMC manuals out there on ebay if you look around that will have wiring diagrams. On a boat that age, there are a number of reasons why a fuel system issue would prevent it from starting.
​There is a procedure to measure the psi that the fuel pump puts out. In my experience these mechanical fuel pumps rarely go bad, my engine has the original on it still. You may have a clogged anti siphon valve on the gas tank. I'd get a manual and then troubleshoot the whole fuel system.
 

Bondo

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3) I know the fuel pump is mechanical in nature. I think the part number is 982997???? Other than disconnecting the fuel line is there any other way to check it?

Ayuh,.... Welcome Aboard,.... Hook up a remote fuel tank directly to the fuel pump with known good gas in it,.....
 

Skyrivers

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The carb is not electronic. What you are looking at is an electrically heated choke. There are OMC manuals out there on ebay if you look around that will have wiring diagrams. On a boat that age, there are a number of reasons why a fuel system issue would prevent it from starting.
​There is a procedure to measure the psi that the fuel pump puts out. In my experience these mechanical fuel pumps rarely go bad, my engine has the original on it still. You may have a clogged anti siphon valve on the gas tank. I'd get a manual and then troubleshoot the whole fuel system.

Thanks for the reply. I took the fuel pump apart last night. The diaphragm is cracked. I will be replacing the entire pump just to be sure it is good. The anti-syphon valve is good. I am hopefull to have the fuel system in good repair after replacing the pump.
 

Skyrivers

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The battery is draining down just sitting. Is this normal? Also I was trying to crank the boat and the positive cable got hot?
 

Bondo

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Also I was trying to crank the boat and the positive cable got hot?

Ayuh,.... Clean both ends of the cables,....

There's corrosion there, as resistance equals heat,....

'n No, the battery shouldn't go dead without use,...
 

CamaroMan

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check cabin/nav lights - u can also try amp load method using a digital multimeter inline - disconnect one fuse at a time to see if it drops.. u shd never really swing more than 5-8 seconds at a time with breaks in between, and after 3 minutes max let it sit a while. Make sure each and every connection from/to a battery/starter/engine block has been sanded shiny, even the washers and bolt surfaces. Put on a LOT of di electric grease and reconnect.

Some batt cables look good but are junk, I had exactly this ssue on a motor swa I did last week - also a 4.3 - the red batt cable looked good but was junk. Replaced it and all good. If u are on salt water forget those junk shiny chrome junk cables from the parts store. Snip them off, buy some heavy duty brass ones and press them one with a big vice/press. Napa might be able to do this. . and grease those too after youre done.
 

Skyrivers

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check cabin/nav lights - u can also try amp load method using a digital multimeter inline - disconnect one fuse at a time to see if it drops.. u shd never really swing more than 5-8 seconds at a time with breaks in between, and after 3 minutes max let it sit a while. Make sure each and every connection from/to a battery/starter/engine block has been sanded shiny, even the washers and bolt surfaces. Put on a LOT of di electric grease and reconnect.

Some batt cables look good but are junk, I had exactly this ssue on a motor swa I did last week - also a 4.3 - the red batt cable looked good but was junk. Replaced it and all good. If u are on salt water forget those junk shiny chrome junk cables from the parts store. Snip them off, buy some heavy duty brass ones and press them one with a big vice/press. Napa might be able to do this. . and grease those too after youre done.


Thank you for the suggestions. I have repaired the boat now. I did get the fuel line purged of air and found the that the ignition coil had gone bad while trying to purge it. Now I will be on the water today after work. I am so thankful for everyone making the suggestions.
 
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