Fuel question

[Brent1342]

Hello Tige community. I recently purchased a 1996 pre 2200 wt and I believe that I am having a fuel problem. Before running my boat I drained all the fuel replaced the fuel/ water separator. Starts with no problem revs up fine on the trailer an once a load is put onto it , meaning putting it into the water and throttling up it cuts out after 3000 Rpms. Once throttle is backed off too 3000 rpms it runs fine. After reading other fuel post I believe the is the fuel lift pump. I placed a fuel pressure gauge onto the fuel rail. And had no fluctuations on the gauge when throttling up under load. The boat maintained pressure in the upper thirties. My question is would I see a drop of pressure at that gauge while its hooked up to the fuel rail indicating a bad lift fuel pump? Engine is a 454MPI.

[chpthril]

What octane are you running and what is the recommended oct? Under load, spark knock could retard the timing, reducing power.

[Brent1342]

I put 91 octane along with fuel stabilizer in it because the Seloc manual suggested to do it for storage I bought the boat in January and did all the maintenance for the winter. New oil, spark plugs, wires, rotor, and rotor cap. There is no knocking popping or cracking. On bogging down after 3000 rpms.

[Brent1342]

Sorry I ment to say "Only bogging down after 3000 Rpms".

[lee]

If it was a pump issue the gauge would have changed.

[Brent1342]

Thanks Lee, I was thinking the same thing that's why I had to ask. I will change my direction to the TPS.

[lee]

I do not think it would be the TPS either.

[TeamAllen]

Do you have any way to check for a trouble code?

[Brent1342]

No I don't I was thinking about buying a code reader. I just might have to do it now.

[robert theisen]

Have you tested the ignition for breakdown under load ?

[Brent1342]

I didn't think about the ignition. I figured it was fine since it started up just fine. I will start and trouble shoot it. Thanks Robert.

[macteacher2]

I had a similar problem with my last boat - turned out to be the plug wires (there were 2 that were in the wrong sequence). It happened right after I purchased it (I had the boat fully serviced) and again several years later (after I had the plugs changed out). Might be the same thing for you?

Hope that helps.

[chpthril]

secondary ignition has a habit of missing under load, but stops if the throttle is leveled off to reduce load.

[Brent1342]

Thanks chpthril.

[boatwakes]

If it's a mercruiser and has the thunderbolt ignition, check the distributor at the base where you should see at least two wires coming out: white with a green stripe and white with a red stripe and if it's been updated, solid black as well. If you only have the two white with green and red stripe wires, update your ignition module to this and it will solve your problem: Mercruiser PN 87-892150Q02 and about $80. If it's been updated already we need to explore some other avenues. Try this first.