Ford 5.0 efi hits a rev limit at 2k rpm

[caravellelegend]

Hello, I having an issue with my 5.0 efi motor here, I just got the whole boat back together and I wanted to test it out on the muffs here in the driveway, and well, it runs beautiful.. fires right up with a tap of the key, however when i attempt to rev the motor it only goes to 1900 rpm then hits a wall then right back to 1900, exactly as if its hitting a rev limiter! It does it weather the motors cold or when its warmed up, so that doesn't seem to make a difference, Id like to find a way to pinpoint what this is before i just start replacing parts, from some of my research I've heard this may be a bad TFI module that could be causing this?..could poor quality fuel be causing this? it seems unlikely but just a thought. In my opinion it something electrical, like an ignition problem causing like a limp mode. Im not familiar with this dinosaur of an EFI system, any help from an old pro would be greatly appreciated, missing some beautiful boating weather!

 

[HT32BSX115]

Re: Ford 5.0 efi hits a rev limit at 2k rpm

Hello, I having an issue with my 5.0 efi motor here, I just got the whole boat back together and I wanted to test it out on the muffs here in the driveway, and well, it runs beautiful.. fires right up with a tap of the key, however when i attempt to rev the motor it only goes to 1900 rpm then hits a wall then right back to 1900, exactly as if its hitting a rev limiter! It does it weather the motors cold or when its warmed up, so that doesn't seem to make a difference, Id like to find a way to pinpoint what this is before i just start replacing parts, from some of my research I've heard this may be a bad TFI module that could be causing this?..could poor quality fuel be causing this? it seems unlikely but just a thought. In my opinion it something electrical, like an ignition problem causing like a limp mode. Im not familiar with this dinosaur of an EFI system, any help from an old pro would be greatly appreciated, missing some beautiful boating weather!

Howdy, AND welcome aboard!

You REALLY NEED to provide the model number so we can determine what you have!

IN GENERAL, You'll need to get yourself an OEM OMC service manual.

UNDERSTAND........ you have a system that is OBSOLETE. Your EFI ECM may NOT even be available for replacement.....! AND other parts may not be available AT ALL.. ANYWHERE.

AND, there may not be ANYONE willing to even troubleshoot your problem......

Sorry about that.

Rick