Done with my echelon! vapor lock

[footndale]

Should be close to this, I believe. 

 

Spring on top. based on serial number of engine http://www.cpperformance.com/s-1847-vapor-separator-tank-sn-and-below-see-note.aspx

 

spring on bottom http://www.cpperformance.com/s-1848-vapor-separator-tank-sn-and-up-see-note.aspx

Edited August 2, 2017 by footndale

[Arick]

42 minutes ago, barefootrocker said:

Well after a year, here we are. We have solved this (seemingly vapor lock) issue. My team is the new owner of the 1994 Malibu Echelon with the injected 454, we bought it from Michigan Boarder in April this year. What it comes down to is inside the VST there is a venting mechanism, which under high temperature or low speed/high load scenarios allows pressure to escape the VST. It is comprised of a small cap, a diaphragm, and a spring. For the first couple years this motor was in use it was assembled with the spring on top of the diaphragm. Upon a revision of the VST top cover, the way the vent functions required that the spring then be assembled UNDER the diaphragm. Somewhere along the way somebody must have pulled the VST apart, and assembled these two components wrong according to a picture in a service manual based on the new design.

So after years of head scratching with this boat, the solution took a screwdriver, about two minutes of work, and didn't cost a dime. We went in and switched the two components to be correct. The way to tell the correct assembly is whether or not the top cover has an elbow on the top or the front. I have a picture to show the difference but can't figure out how to add it here.

We took it out last night and abused it every way we could. Long heat soak loaded idle, high speed runs to a dead stop and shutdown, nothing could get it to stumble or fail. Runs perfectly smooth and so strong. I had 47mph at 4,550 in a chop with the original Legacy (OJ) prop. It's all there.

I hope this can help someone out there. If you have questions let me know.

 

9 minutes ago, footndale said:

Should be close to this, I believe. 

 

Spring on top. based on serial number of engine http://www.cpperformance.com/s-1847-vapor-separator-tank-sn-and-below-see-note.aspx

 

spring on bottom http://www.cpperformance.com/s-1848-vapor-separator-tank-sn-and-up-see-note.aspx

 

This should be added to the resource section!

[barefootrocker]

Jason K- I got very lucky and in googling these issues I stumbled onto a page on Offshoreonly of a guy having this exact issue with a twin 502 rig he was running. He listed the symptoms and when/how they happened and I just knew it was exactly what I was looking at.

Footndale - thanks for adding the pics. And the thing is, those aren't the only ones out there. The one that finally made me realize I was on the right track was one that showed both configurations with a note at the bottom saying which was which according to which style top cover the VST had.

We were following the correct parts diagrams, off of CP Performance using the serial number lookup. But the couple times we pulled the VST apart, not knowing it was significant, we just put it back together the way it came apart. Who wouldn't?

It's such a simple yet critical thing, it's almost funny. Now I don't think this is the silver bullet for everyone's vapor lock issues, but costing $Free.99 it's certainly worth a look. Before we discovered this we had already done plugs and wires, cap and rotor, new mechanical pump, new electric pump, new MAP sensor, and all new fuel lines (and routed them even further from the block). We've got some money into it now, but it's not for nothing. Those are things that are certainly worth replacing on a boat that's 24 years old, and it runs incredibly now.

Edited August 2, 2017 by barefootrocker

[MikeDe]

This is like reading a build thread. Cool seeing the issue finally resolved.

[footndale]

55 minutes ago, barefootrocker said:

Jason K- I got very lucky and in googling these issues I stumbled onto a page on Offshoreonly of a guy having this exact issue with a twin 502 rig he was running. He listed the symptoms and when/how they happened and I just knew it was exactly what I was looking at.

Footndale - thanks for adding the pics. And the thing is, those aren't the only ones out there. The one that finally made me realize I was on the right track was one that showed both configurations with a note at the bottom saying which was which according to which style top cover the VST had.

We were following the correct parts diagrams, off of CP Performance using the serial number lookup. But the couple times we pulled the VST apart, not knowing it was significant, we just put it back together the way it came apart. Who wouldn't?

It's such a simple yet critical thing, it's almost funny. Now I don't think this is the silver bullet for everyone's vapor lock issues, but costing $Free.99 it's certainly worth a look. Before we discovered this we had already done plugs and wires, cap and rotor, new mechanical pump, new electric pump, new MAP sensor, and all new fuel lines (and routed them even further from the block). We've got some money into it now, but it's not for nothing. Those are things that are certainly worth replacing on a boat that's 24 years old, and it runs incredibly now.

Curious if you used the engine serial number off Mercury's site, did it show the correct VST?

Edited August 2, 2017 by footndale

[Woodski]

Just a minor note, if you have to replace the pump (#8), get a decent AC Delco unit and steer away from the Airtex replacement as they are prone to early failures.  It is the same pump used in most GM in tank automotive fuel pumps.

[barefootrocker]

@footndale actually no, serial number lookup on the Mercury site shows the wrong diagram, with the spring underneath! Unless maybe the VST in our rig is not the original to the motor. No idea I guess. I don't have enough of a history to know.

@Woodski unfortunately yes, we did go with a cheap electric fuel pump. Being that our symptoms were so strange and inconclusive, I couldn't confidently pin it on the pump, so rather than spend $700 or whatever, I opted for $70, just to see if it would get us off the ground. I'm fully expecting that to be a necessary replacement in the future. Do you have an AC Delco number for that pump, such that I could steer away from the Quicksilver price?

[Woodski]

@barefootrocker:  I would have to do some digging on the AC fuel pump number.  It is actually a very common pump, I did the google search on fuel pumps for a GM vehicle to hone in on that pump.  The actual pump is used in most GM in tank fuel pump units (they cost ~$300 and come with the sender, etc. in a 'can'), I bought just the pump itself and then did the swap.

Edited August 2, 2017 by Woodski
update information

[Woodski]

@barefootrocker:  Here is a link to what appears to be the same pump:

https://www.amazon.com/Delphi-FE0115-Electric-Fuel-Motor/dp/B000CGFUHK/ref=pd_lpo_vtph_263_bs_t_2/137-6992102-2468548?_encoding=UTF8&psc=1&refRID=Z92X5149JCMQFP26X687

Given the note that they pair with 'other' manufacturers I would take this and further the search to get an AC original.  As noted earlier, the Airtex Chinese special lasted a whopping 6 months.  AC Delco has been pumping away for a few years now.

[barefootrocker]

Well guys it's long overdue, but we finally put the Echelon to work last night. Pulled a bunch of show acts including a couple pyramids, and ended the night with some footing:

 

[BlindSquirrel]

I want to try footing, but it seems there is never an easy fall......

[Michigan boarder]

57 minutes ago, BlindSquirrel said:

I want to try footing, but it seems there is never an easy fall......

They are actually the least painful falls of wake sports.  Except surfing.  You skip along and disperse the energy.

[Michigan boarder]

That engine sounds fantastic, so glad you guys got it dialed in.  Thanks for sharing!

[footndale]

1 hour ago, Michigan boarder said:

They are actually the least painful falls of wake sports.  Except surfing.  You skip along and disperse the energy.

ahhh, yes and no.   I've only really fallen 2-3 times this year. Not really learning anything new. But damn, today crossing wake and falling, hurt. 

[jk13]

2 hours ago, barefootrocker said:

Well guys it's long overdue, but we finally put the Echelon to work last night. Pulled a bunch of show acts including a couple pyramids, and ended the night with some footing:

Eagle's Club to the corner turning left to Bluegill.

So you bought the twin of @Michigan boarder and my open bow boats from the man himself and brought it to my home lake...what are the chances. Hope to see it our there sometime! Occasionally we idle through the show course and swim at one of the islands with the dog on Sunday nights.

Glad you got it sorted out, they are great boats.

Edited August 8, 2017 by jk13

[Woodski]

@barefootrocker:  +1 on the video, 50 seconds of big block music.  Challenge:)  deep water starts w/ those three, I know it can be done (although I don't have video of it) as my measly but modified SBC pulled 3 up long line so the BB should have noooo problem.

PS:  butt slides are much more comfortable way to release the rope -but- your gang is consistent!

[barefootrocker]

@jk13 Awesome! Yeah we run shows on Sundays and practices on Mondays at that site. If you see us out there stop by!

@Woodski Well unfortunately all three of them learned show-ski style and don't do deep-ups. I'm working on that. There are three of us that do but two were gone that night and I'm benched with a bad hamstring at the moment (so I'll have to report that yes there are bad barefoot falls haha) As far as the butt slide ending, they all know it but the last run of practice is always gang foot and it's survivor style last man standing so out the front is kind of the only option ;-)

@BlindSquirrel Footing is very approachable and quite safe, if done on a boom with a competent instructor. Totally doable.

[CCole]

On 8/2/2017 at 8:58 AM, barefootrocker said:

Well after a year, here we are. We have solved this (seemingly vapor lock) issue. My team is the new owner of the 1994 Malibu Echelon with the injected 454, we bought it from Michigan Boarder in April this year. What it comes down to is inside the VST there is a venting mechanism, which under high temperature or low speed/high load scenarios allows pressure to escape the VST. It is comprised of a small cap, a diaphragm, and a spring. For the first couple years this motor was in use it was assembled with the spring on top of the diaphragm. Upon a revision of the VST top cover, the way the vent functions required that the spring then be assembled UNDER the diaphragm. Somewhere along the way somebody must have pulled the VST apart, and assembled these two components wrong according to a picture in a service manual based on the new design.

So after years of head scratching with this boat, the solution took a screwdriver, about two minutes of work, and didn't cost a dime. We went in and switched the two components to be correct. The way to tell the correct assembly is whether or not the top cover has an elbow on the top or the front. I have a picture to show the difference but can't figure out how to add it here.

We took it out last night and abused it every way we could. Long heat soak loaded idle, high speed runs to a dead stop and shutdown, nothing could get it to stumble or fail. Runs perfectly smooth and so strong. I had 47mph at 4,550 in a chop with the original Legend (OJ) prop. It's all there.

I hope this can help someone out there. If you have questions let me know.

I just want to say thanks for figuring this out.  No more vapor lock on our 94 Echelon thanks to you.  

 

[barefootrocker]

@CCole excellent!