200 xs surging issue.

[comptonbass]

0t819305 2004 200xs power head on a ridge back offshore mid section.

surges under mid range cruise idles fine and is fine under wide open throttle conditions.
has 454 hours Here is what been done to it....new powerhead gaskets, new fuel psi regulator, new tracker valve, new fan belt, new fuel injectors, new air injectors, new air compressor, new fuel lift pump, new iridium plugs, new stainless 3.0L driveshaft, new water pump, new shift shaft, new carrier bearing and seals. Lost on what to do next thanks in advance

[comptonbass]

Nothing?

[leonreno]

Give it to the week days, many of the experts don’t read or post over the weekend. How much of a surge are we talking about, how many rpms? Does it go up or down?

[comptonbass]

Give it to the week days, many of the experts don’t read or post over the weekend. How much of a surge are we talking about, how many rpms? Does it go up or down?

running 3-4K rpm it surges up and down maybe around 200 rpm.

[JOE54]

whats fuel psi doing when surging ,steady or fluctuating hmmmmm

[comptonbass]

whats fuel psi doing when surging ,steady or fluctuating hmmmmm

Gonna try that when I get a better gauge

[JOE54]

[comptonbass]

Ok reporting back having more symptom. It runs fine for a little if you let it sit then when you take off and cruise for a bit and hammer down I get a solid warning at wot if I let off just slightly the buzzer quits. Here’s where it gets weird when you let it fall off plane it stumbles a little and dies then fires right back up and runs good at idle till you try to go again and it won’t go just sneezes and stumbles. Fuel pressure is 95 and air is 85 air leaks down slowly after shutting off and fuel pressure leaks down instantly as soon as you shut it down.

[JOE54]

you gotta fuel psi and or supply to mtr issue

[comptonbass]

you gotta fuel psi and or supply to mtr issue

I figured that but what would cause the fuel psi to drop as soon as you shut it off new primer bulb and fuel lines installed.

[comptonbass]

Spoke to don tonight on the phone what a good guy to call and help appreciate you!

[Merc2.4]

Did u find your problem?

[comptonbass]

Found a problem was the seal around the top of the high pressure fuel pump that fixed my holeshot but I still have a warning buzzer at wot!

[JOE54]

should be able to scan faults with cds or ddt

[comptonbass]

That’s what I’m waiting on. Someone that is available that has one.

[JOE54]

[comptonbass]

Update. Fixed the fault was the water pressure sensor stuck in range. Also found a broken wire on the air compressor temperature sensor. Now no more beeeeeep. BUT I STILL HAVE THE HOLESHOT ISSUE ONLY WHEN WARMED UP GOOD. If I let it cool off it runs great plugs have 5 hrs on them and checked compression cold was 95 on all six fuel pressure holds good now and so does air. I cannot figure out why it has this holeshot/stalling issue only down off plane once on plane no issues at all did a coil test on ddt and all fired the same. Also idles kinda uneven all injectors were replaced 6 hrs ago and 1 air injector replaced and the rest cleaned. I’m pulling my hair out all plugs were a prefect bronze color after running. So the only thing I can think to do is take all my testing equipment to the lake and see if i can find something when it’s acting up! Any ideas would be appreciated!

[comptonbass]

Took reeds out today and all looks good has carbon reeds and the cages look great.

[JOE54]

bet they did too reed not problem, do fuel psi test when it gets hot

[comptonbass]

What about a bad shift interuppter switch