F225 TXRC bogging down - fuel rail pressure question

[Crazy Train]

That should say 'back in the ****'. Also, before and after photos of the VST HP pump filter.

[Crazy Train]

Success! Finally completed the remainder of the Spring re-commissioning work and launched her yesterday. Ran perfectly: instant start-up; smooth idle; no hesitation or bogging during acceleration at able to achieve and maintain WOT/high speed. Recapping, I: replaced all the gas in the boat fuel tank, changed Racor fuel filter and engine on-board fuel filter, had the fuel injectors cleaned, cleaned VST and VST filter, replaced spark plugs, and replaced the F filters. Of all of the items that I changed, I attribute my original issue (bogging down) to a mostly-clogged VST filter since it was the only item that clearly was degraded (clogged). I also believe that the majority of the material that clogged the VST filter is generated from within the VST or within the near-by fuel loop.

Thanks to this forum for all the help. Rockfish season opens this coming Saturday (Chesapeake Bay), and I'm back in the ****. Good luck!

[rodbolt17]

3.3, you can change all 6 injectors and clean the VST in 2 hours. the F1115 and 150 in 1.5.
its called maint .
do it now and again.
I am glad I never changed a fuel pump in my 87 3/4 ton chebby.
I just wish the only time it died was not right after I filled the tank.

[oldmako69]

Take a look at the pumps below.. While one example is for a Zuke, they make one for Yams. Just dig around a bit as my link has expired. The claim to fame for these pumps is the carbon brushes (?) inside as opposed to any metal. The water absorbed by and contained in the E10 eats away at the innards of the metal pumps and is likely what has corroded your screws.

This all ties into the guy I mentioned earlier who cut a used HP pump in half and discovered that it was rusting internally. His Racor and first stage filter were free from crud, yet the VST screen was full of it. I had a similar condition.

The HP pump, as I understand it delivers more flow to the fuel rails than the injectors squirt. The excess flow is shunted back to the VST where the little bits of crud from inside the HP pump then clog the VST HP screen. Some of the crud also winds up in the F filter, and some in the injector screens.

One of my HP pumps crapped out. I used this one.....

https://www.ebay.com/itm/29139369582...%3AMEBIDX%3AIT

I've only put about 75 hours on it, but so far so good.


Here are the carbon pumps, or as near as I can find of them...

https://www.ebay.com/p/Kemso-High-Pe....c100011.m1850

https://www.ebay.com/p/Fuel-Pump-for....c100011.m1850

[TownsendsFJR1300]

Those screws simply rusted.. Obviously not SS

If you can find SS screws, same size, I'd install those instead of the rusty ones.

Also, just to confirm what's in the bottom of the VST, put a small magnet to it. If it's rust, the magnet will attract it....

.

[Crazy Train]

I might attribute HP pump corrosion to ethanol. How many hours on your motor?

I say this offhand based on my experience. May have some relevance or not. I disassembled my 11 year old VST for the first time and found nothing. 540 hours at the time. Only use non-ethanol. Fairdeal runs ethanol with no issues. But typically runs his boat 300+ hours a year. Not much sitting around.

You may be doing all you can with ethanol being the only fuel available. Gets cold up there. Hard to do much in January or February to cycle the fuel.

Thanks 46: 704 hours on the motor. I cannot rule out fuel contamination due to particles from inside the HP pump, but it is highly, highly likely that those two screws are shedding particles into the VST. Attached is a photo of one of the screws after a moderately-light scrubbing with a brass brush. Thanks!

[Crazy Train]

Photos of the two screws.

[Crazy Train]

redish color may be rust

I cleaned off the two screws I mention above that are on the inside of the lid of the VST. Those two screws were covered with a reddish-white substance - the same sand-like substance that was in my HP pump filter. Of note, those two screws are steel (magnetic) that hold two stainless steel plates on to the cast-aluminum VST lid. Very possible it is rust. Another theory: based upon the appearance of the reddish-white substance (almost granular), and the dissimilar metals, maybe galvanic action is causing the reddish white substance to form. Regardless of how it is formed, the substance is falling down into the bottom of the VST and clogging the HP pump filter.

[pstephens46]

I am using ethanol fuel (10 percent ethanol) treated with sta-bil marine (the blue stuff). Tough to find non-ethanol fuel here (Maryland). The fuel has been in the tank since last spring. I am in the process of recycling the fuel out of the boat and into my truck. Since the truck is running fine, I don't attribute the issue to old fuel.

I might attribute HP pump corrosion to ethanol. How many hours on your motor?

I say this offhand based on my experience. May have some relevance or not. I disassembled my 11 year old VST for the first time and found nothing. 540 hours at the time. Only use non-ethanol. Fairdeal runs ethanol with no issues. But typically runs his boat 300+ hours a year. Not much sitting around.

You may be doing all you can with ethanol being the only fuel available. Gets cold up there. Hard to do much in January or February to cycle the fuel.

[Crazy Train]

Did anyone ever ask what fuel you are using? Ethanol? With extended storage periods?

I am using ethanol fuel (10 percent ethanol) treated with sta-bil marine (the blue stuff). Tough to find non-ethanol fuel here (Maryland). The fuel has been in the tank since last spring. I am in the process of recycling the fuel out of the boat and into my truck. Since the truck is running fine, I don't attribute the issue to old fuel.

[pstephens46]

redish color may be rust

Which made me wonder what fuel sitting how long?

[99yam40]

Per RB, that debris is from the brushes of the HP pump

redish color may be rust

[TownsendsFJR1300]

Per RB, that debris is from the brushes of the HP pump

[pstephens46]

I have finally found the time to pull out the VST and the HP pump filter. The bottom of the VST had a small accumulation of reddish-sandy colored particles with a few black specs. The HP pump filter was about 50 percent clogged with the same type of particles. Wish I could figure out how to post photos, but that filter is now clean. I also pulled the fuel injectors and had them cleaned. The injectors ranged from zero to about 10 percent flow rate degradation (58 out of 64). The old injector screens had some particulate matter build-up, but nothing of what I would call significant. Of note, there are some screws on the inside portion of the VST lid that have some corrosion; that corrosion seems to match the particulate matter at the bottom of the VST and the HP pump. As in the OLDMAKO quote above, my RACOR was clean, the on-engine filter was clean, but the VST was clogged - meaning the VST eroding/corroding and clogging itself. So, I am racking my engine bogging issue up to a clogged HP pump filter. Time to put it all back together and test run it.

Did anyone ever ask what fuel you are using? Ethanol? With extended storage periods?

[Crazy Train]

One potential source (I read about this on another forum) is the HP pump itself. Moisture contained within the hygroscopic ethanol rusts the internal metal components of the Hi PSI pump. As I understand it, you don't need suspended, free water in the fuel, just moisture contained within the E10. That moisture corrodes the pumps internals which then get pumped out to the injectors. The fuel returned to the VST from the fuel injector supply loop - (wrong nomenclature I'm sure, but you get the idea) contains these ruts bits along with the little bits of crap sloughed off by the internal degradation of the fuel hose. There is a vendor who sells a replacement pump which contains zero metal. Supposedly its got ceramic guts. I cannot vouch for it.

One guy actually cut an old HP pump open and discovered it rusting out internally. So, you can change all the filters short of the VST all you want, but you still can't prevent detritus from gumming up the VST fuel pump filter or the injector screens. At least, this is how it appears to me.

On my boat, the external Racor was completely clean. The first stage YAM filter was fine. Yet there was crap in the VST screen. I did not cut open the F filter, I just tossed and replaced it. Another 30 dollar bill.

I am giving consideration to adding a simple glass see-through in place of the F filter. If I can relocate it to a more sensible location I will.

I have finally found the time to pull out the VST and the HP pump filter. The bottom of the VST had a small accumulation of reddish-sandy colored particles with a few black specs. The HP pump filter was about 50 percent clogged with the same type of particles. Wish I could figure out how to post photos, but that filter is now clean. I also pulled the fuel injectors and had them cleaned. The injectors ranged from zero to about 10 percent flow rate degradation (58 out of 64). The old injector screens had some particulate matter build-up, but nothing of what I would call significant. Of note, there are some screws on the inside portion of the VST lid that have some corrosion; that corrosion seems to match the particulate matter at the bottom of the VST and the HP pump. As in the OLDMAKO quote above, my RACOR was clean, the on-engine filter was clean, but the VST was clogged - meaning the VST eroding/corroding and clogging itself. So, I am racking my engine bogging issue up to a clogged HP pump filter. Time to put it all back together and test run it.