PCM Engine Question

I guess nobody wants to tell you that there was no electric fuel pump on a carbureted 99 SN at least as it was built.

Maybe somebody added something over the years. Maybe you're hearing something else.

You could play "follow the fuel line" or you could turn the key to the RUN position and play"find the noise"

Otto,
Any luck finding what the noise is?

Otto Throttle wrote: Hey Guys! There is an electric fuel pump along with the mechanical pump on the HO 285 HP Carbed Engine in 1999. It only runs when the engine is running except for when the ignition is turned to start! Check out the PCM Manual! I know who would have thunk it!

I guess you should say which PCM manual you're looking at, maybe it's the one in the link

link

If the page you're reading looks like this, I'd say it's "not exactly accurate". You'll have to rotate the picture yourself or goto page MT4 in the linked manual



Your engine is a PLP (285 HP) so if you believe the words that are there you would have only an electric fuel pump and no mechanical pump.

I'd say the people writing and proofreading the manual forgot to include PLP right after the PLD in their discussion of mechanical and electric fuel pumps.

Do you see words that say "Otto's 285 HP engine has a mechanical and an electric fuel pump" ? Do you see words that say any of their engines with a carburetor have both an electric and a mechanical fuel pump.?

The part that talks about "Carburetor equipped engines with electric fuel pumps" is for a GM engine, in this case a 454 with ONLY an electric fuel pump. It has no provision for a mechanical fuel pump in the later years.

Look at the wiring diagram for a carbureted Ford on page MT14 of the same manual and you don't see anything associated with an electric fuel pump.

Now continue on to page MT15 for a GM with a carburetor and there's an electric fuel pump and wiring and it's associated pressure switch and fuse just like what was talked about of page MT4.

Early GM's had mechanical fuel pumps but as the carburetor went the way of the dinosaur they quit machining the provision for a mechanical fuel pump in the block so an electric pump was needed.

A 351 marine Ford always had the mechanical fuel pump provision since the fuel pump was mounted to the timing cover which was a different part on a marine engine as compared to the auto engine it was based on.

You could also call somebody like SkiDim and ask them if your carburetor equipped 285 HP Ford engine has 2 fuel pumps.

Think about it, if you have a 6 psi electric pump feeding a 6 psi mechanical pump you'd now have 12 psi to the carburetor and they don't like that.

Thanks for the response...I fly Heavy Boeing Jets and I expect what is in a service manual to be accurate. Can you imagine if I had to dump 250,000 lbs of fuel to get to max landing weight and they had the procedures for a DC8 instead of a B777? Im just saying...

Otto Throttle wrote: Thanks for the response...I fly Heavy Boeing Jets and I expect what is in a service manual to be accurate. Can you imagine if I had to dump 250,000 lbs of fuel to get to max landing weight and they had the procedures for a DC8 instead of a B777? Im just saying...

I figure that as long as humans are writing manuals, procedures etc. for almost anything, there will be mistakes or words that people can misinterpret no matter what the manual is for.

With a certain amount of familiarity with the engine/boat in this case you can understand what the manual is telling you. It's not written to cover one specific engine or year of engine.

I can understand that you're trying to get familiar with the boat and the best way to do that is with your eyes and hands,crawling around, removing panels etc. And.................keep asking questions

Most of the filters/separators are 10 micron which will work just fine.

Thanks! I want to change it this spring...any tricks to doing it, Like filling it with gas before you put it on?

Otto