Am I having fuel pump problems?

[rem_pss308]

1999 X-star with LTR 350 with 330 HP


Motor idles fine.
when under a load ( pulling a rider )
when I get to 3000-3100 rpms the motor dies, sometimes backfires, but doesnt shut off.
after doing this when I let the throttle off. the motor idles real high for a few moments, then goes back to normal.

Im thinking that my fuel pump is not pumping enough, or maybe fuel filter.

is this typical behavior for this problem?

could it be possible that its the spark arrestor needs cleaning.

Plugs, wires, and all four coil pacs are less than a year old.

Does any one know what the fuel pressure should be when checked?

[rem_pss308]

Took the fuel filter out today. it was nasty. blew it out with blower. reistalled it. but it still does the same thing.
took the plugs out and looked at them. they were good.

Fuel pump assembly says 40 psi.

Ill try to get a fuel pressure gauge and check the pressure.

( the hose in the fuel pump was not kinked )

[Jim@BAWS]

Change the FUEL Filter by the pump...a SILVER cannaster

Remove the FUEL Pump and remove the small screen on the bottom. You will be a dental
pick.

Try that

Jim@BAWS

[rem_pss308]

Replaced the fuel filter today.

Still does the same thing....

Will get a gauge and check the fuel pressure this weekend.


When I reved the engine in neutral. it didnt cut out until about 4000-4200 rpms.

could it be electrical?

Bad spark plug wire. ( even though they are less than a year old )

ECM ?

[Jim@BAWS]

"Remove the FUEL Pump and remove the small screen on the bottom"

Jim@BAWS

[TX.X-30 fan]

80 bucks and you got a new pump, I would do that before I ever changed the filter. Just push the valve on the rail and see it it squirts gas.

[rem_pss308]

Still no luck.

took the screen out of the fuel pump. still does it.

Bought a fuel pressure gauge.

40 psi at key turn on.

42 psi at half throttle

42 psi at 4500 and 5000 rpms

with no load, in neutral. it starts skipping at about 4500 prms. fuel pressure never goes low?

after the skipping, when I put at idle it revs high about 1200 rpms.

I need ideas.

How can I check something else?

Its driving me crazy.

Ive had the plugs in it over the summer and no problems. They are NGK

The owners manuel calls for ac MR43LTST

Could they have broken down?

[rem_pss308]

Checked the coil pacs today, and one of them had some rust where the spark plug wire connects to it. So replaced it. others looked good.
Changed the plugs with AC plugs that the owners manuel called for.

still stalls after 3500 rpms, then stays reved up for a breif moment when I put it back to neutral.

Anyone have any ideas?

[rem_pss308]

Found some corrosion on the plugs going to the ECM and cleaned them the best I could. Boat is running better, but still cuts out at full throttle. has slight misfire at 3200 prms, but doesnt bog anymore. Bogs at full throttle.

[rem_pss308]

Seems like its fixed.

Changed the coil packs, and the heat/cool sensor that sends the signal to the ECM.
ran like a champ yesterday.