Power Loss

You can plumb a vacuum gauge into the suction side of the fuel pump...if the vacuum increases (bigger numbers) when the power loss occurs, you have verification something is restricting the inlet...I'd suspect crud in the tank is covering the pickup tubes' screens...

Yes, that's the way it's acting. I have inspected the fuel in tank through sender hole, and tanks looks clear, been through about 200 gals of gas in last month, and pulled the pickup tubes which were clear of debris (and no screen on them), and even polished the fuel last year sucking from the bottom of the tank, with no change. What you're suggesting makes sense, I just don't see it being only cause with all I've tried. Thanks for idea-

I don't see any post saying that you pulled and cleaned the anti-siphon valves. Your previous post #22 suggests that you would look into it but I don't see a post about actually removing and cleaning them. Has that been done?

Erich

The other scenario would be loss of vacuum at power loss...on the suction side. means something is allowing air to enter - leaking shutoff valve, spin on filter not tight, etc.

BTW, intermittent issues are usually the most challenging to find the real cause of...been know to separate the men from the boys, more than once!

Update..... been running at 1800 rpm max all summer burning down as low as possible before draining tank. Seemed to run fairly smooth there. Got down to about 1/4 tank, pulled to gas dock and pumped out 120 gal, emptied tank, and put 1/2 tank fresh gas in (225 gal, ouch!). On way out from gas dock, started running so rough that couldn't even keep on side lit before the other one died. Limped back to slip continually starting one then the other....as bad as it has ever run. Worse than when went to gas dock an hour before. Can't believe all I did is empty tank, and put fresh in, and it ran worse!!

Thinking I stirred up a little remaining crap in tank, changed out racors with fresh ones, to no avail. At a loss.....

If things were fine with the portable tank plugged in, then it is likely bad fuel in the tank...many will tell you you need to get ALL the contaminated fuel out before you add fresh fuel...I haven't heard of any magic in a can that really eliminated the crap that ethanol induces

erich said:

I don't see any post saying that you pulled and cleaned the anti-siphon valves. Your previous post #22 suggests that you would look into it but I don't see a post about actually removing and cleaning them. Has that been done?

Erich

Click to expand...

I agree. He never says whether he has checked those or not. I found this thread because I am having he exact same problem with one of my Crusader 454 with QJets. I am going to check the anti siphon valve and the screens tomorrow. My problem is more intermittant. Runs great one day and then the next won't go over 3200 then it starts cutting out. I have replaced fuel pump, filter/seperator, cap, and rotor so far.

STOUTNER said:

I agree. He never says whether he has checked those or not. I found this thread because I am having he exact same problem with one of my Crusader 454 with QJets. I am going to check the anti siphon valve and the screens tomorrow. My problem is more intermittant. Runs great one day and then the next won't go over 3200 then it starts cutting out. I have replaced fuel pump, filter/seperator, cap, and rotor so far.

Click to expand...

I pulled out my anti-siphon valves and they were completely clogged up with what looked like old fuel that had gummed up. It was a coffee colored gummy substance. They were clogged so bad I'm surprised the boat ran as well as it did. I will be on the boat this weekend and am hoping this cures my problem. I think it will.

Had the same type of problem two seasons ago. Set up an auxillary 6 gal. tank and they ran fine. Put an add on Craig's List and some guy from the Farm Bureau came and got the fuel. Filled the tank, added a double dose of Star Tron and off she went.
Nightstalker

Thanks for the suggestions. I checked a/s valves way back when started this trying to stay simple first...even ran with a/s removed for troubleshooting, and with gas cap off, after blew threw vent hose for vent check. Admit I have not checked the a/s valves again this year.

E-mailed several times with Crusader rep last year, who basically just focused on what the proper fuel pressure should be at the rail. I sent off an update to him last week, and haven't heard back.. hope to hear.

Sportsman said:

Thanks for the suggestions. I checked a/s valves way back when started this trying to stay simple first...even ran with a/s removed for troubleshooting, and with gas cap off, after blew threw vent hose for vent check. Admit I have not checked the a/s valves again this year.

E-mailed several times with Crusader rep last year, who basically just focused on what the proper fuel pressure should be at the rail. I sent off an update to him last week, and haven't heard back.. hope to hear.

Click to expand...

I took my boat out last night after cleaning a/s valves and it ran better than ever. No issues at all. I think my issue is solved. I would double check yours because they may be clogged again if you had debris floating around in your fuel tank.

After another summer of troubleshooting……finally pulled all the injectors for bench testing. 6 of them were not spraying to spec, and 3 were so damaged, they had to be replaced. They reported back a lot of dust-like particles found, and could be cause of injector probs, and pump failure. Thought we had it, Both ran up over 4,000 wot for 1 trial, now port is stalling again…..
​ I replaced both fuel pumps last year, and now port one is gone again they say……guess about to replace.

I am about to install the big Racors, as discussed in other thread Racors for Ethanol. Question is….is there any other filter system to look at for the dust particles. etc? I see some 2 micron for diesel in the WM catalog, but the Racor 10 microns seem to be the only ones for gas… and they claim to be sufficient for stand alone filters, no secondary needed. So, thought again, is to bypass the old filters, and work with the more accessible new big Racors. Also, fear just adding a 3rd filter in-line may cause fuel pressure to suffer.

Any thoughts before attacking?

Empty your fuel tank, get it professionally flushed out, change to 10 micron fuel filters, change bad injectors, add new fresh gasoline to tank, and you will be all set in my opinion. That "dust" you speak of is most likely gummed up fuel that has been partially broken down by fuel additives. I had that happen after I added Startron to my fuel tank. It broke down the gummy fuel but did not dissolve it all of the way. The participles looked like really finely ground coffee or espresso....

You do want to be concerned about having too many filters on the suction side of the fuel pump...too much restriction on the suction side will impact engine performance and can also reduce pump service life...

As far as the ratings on a racor filter, call their tech department for any "unique" application...many filters will work in other than advertised uses with some tradeoffs...they also have a vast experience base and some of the techs will assist in identifying potential contaminents...costs only your time so you don't have anything to lose...

Ya, that was my thought, don't want to cause too much restriction.... I would think the one filter 10 microns would be sufficient from everything I read. Good thought on talking to racer tech...thx

You can plumb a vacuum gauge into the suction line to see how "hard the pump is working"...Crusader specs it at only a couple inches of mercury...