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New Style Fuel Pump


Tom Baker

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Anyone else having issues with the new style fuel pump? I installed one on a CTSW, and I'm getting low pressure and high fuel flow indications. Everything is OK when I do a static run up on the ground, but the issues show up in flight. I have tried the vent line in 2 different places. I'm about ready to put the old pump back on.

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  • 3 weeks later...

As an update I ordered the new pump from CPS pm Jan 21 and it arrived yesterday.

 

No huge rush to replace it, but may do it prior to my carb overhaul as to not do too may changes at the same time.

 

Still waiting on my transponder and intercom repairs, with my panel out can't start the plane anyway.

 

And this is the view from our from porch:

 

12460659384_33f157cb47_c.jpg

 

Blizzard of the century!

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Actually poor insulation in the roof will also release excessive heat into the ice and snow buildup, which leads to icicle formation. The sun or insulation, or both, can lead up to that.

 

Since we don't know about his housing maintenance, he might just have torn up shingles, so either way, it could happen.

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Cold roofs are now the norm primarily to avoid ice on top of the roof structure.  I built the house in the photo in 1989 and filled the cavities (R-38 fiberglass) as well as sheathed the rafters (1" polyisocynurate) to address thermal bridging but it is still a warm roof structure and the heat loss is through the roof sheathing as opposed to through a system of vents.  

 

The biggest cause of ice damns are fireplace chases and after that heat loss through warm roof structures.  If the sun were the source of the melt/freeze you would see evidence of that process on all outdoor vertical surfaces not just on roofs and flowing from roofs.

 

I just finished insulating the biggest structure in Inyo county, it once housed 2 DC9s.

 

post-6-0-72427400-1392152166_thumb.jpg

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Anyone else having issues with the new style fuel pump? I installed one on a CTSW, and I'm getting low pressure and high fuel flow indications. Everything is OK when I do a static run up on the ground, but the issues show up in flight. I have tried the vent line in 2 different places. I'm about ready to put the old pump back on.

so Tom,,did you solve the problem with the new fuel pump ?

 

about drain hose location..? where/how did you do it ?

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  • 2 weeks later...

so Tom,,did you solve the problem with the new fuel pump ?

 

about drain hose location..? where/how did you do it ?

I too am curious as to where everyone is placing the vent hose on these newer carbies so as not be in a high or low pressure situation whilst being still away from  the exhaust ?

 

Pete

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Just run it back up under the cylinders on the right side to the firewall and down to about 2" before it reaches the edge of the open cowl. No matter how you route it just don't extend it out into the air stream. Leave it back inside the cowl. You don't want ram air or a high negative pressure.

 

P.s.

The new pumps can weep once in a great while so if you see a dribble inside the clear hose don't worry unless it is a steady leak. Some don't weep and some do.

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I had it like Roger did at first, but I changed it. Now I go down under the landing light and tie to the left oil cooler fitting, and tie to the top radiator fitting. The hose extends about 5" past the radiator fitting and sits right next to the cowling. On the LS I tie it to the coolant thermostat housing. It's much easier to route that way, takes less hose, and it is easier to inspect.

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..

The new pumps can weep once in a great while so if you see a dribble inside the clear hose don't worry unless it is a steady leak. Some don't weep and some do.

Roger,

 

You are correct about that mine  is weeping already and I haven't even turned the prop- Thanks for the reply.

 

Tom

 

Thanks too - that gives me a couple of options to try.

 

Pete 

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  • 5 months later...

Has anyone else noticed a higher fuel burn with the new pumps installed?  I recently got my CTLS back from annual (new pump installed) and now I'm seeing a fuel burn rate of around 5.2 GPH @ 4600 RPM (4.5 PSI) and 6 GPH @ 5200 RPM (4.6 PSI).  I've even seen rates as high as the mid 7s during climb out (Maryland in the summer) when I can't remember seeing anything higher than 6.3-6.5 GPH previously.  Another oddity is that at 5200 RPM both EGTs are in the yellow around 1140 degrees.  I can't say I'm happy with the folks who did this year's annual.  Any suggestions?

 

Lee

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What is the new fuel pressure and how many hours on the carbs?

First make sure you aren't leaking any fuel through the fuel drain hose on the bottom of the pump and then make sure you are not leaking any fuel through the carb vent lines. These need to be checked with the engine running and a little rpm. If you have carbs with a little time on them it is possible that the needle valves need replacing because they aren't holding back the new pressure. The other problem may not be the pump and you have an issue with the fuel flow transducer. Fill your tanks and take an accurate measurement by dipping them. Then go fly a long leg or a couple of flights. Then see if the electrical fuel change is the same as dipping the tanks.

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Thanks everyone for the replies.  The maintenance shop did do a removal/assembly of the carbs this year and the carbs were rebuilt last year during the five-year rubber replacement at another shop.  I have since learned that the shop that worked on my bird this year is going through its issues with worker happiness and quality of work.

 

To answer Roger's questions: fuel pressure runs in the mid 4s (PSI) while in cruise and the carbs have about 115 hours on them since last year's rebuild.  I'll check for leaks this week and will let you all know what I find.  As for tracking fuel usage through dipping and the Dynon readout - recent experince 9last 15 hours) shows I have 1 to 1 1/2 more gallons of fuel than the dynon readout for about every 10 to 12 gals the dynon says I burn.  Transducer perhaps?  I have a local friend with a LSRM and own a Gobash.  I may have him look at the carbs.

 

More to follow...

 

Lee

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Back on point...

 

My new style fuel pump is still sitting in its box in my hangar.

 

Just can't get motivated to start messing with a pump that's been working fine for 7 years and about 400 hours.

 

Would probably stick the new one in my baggage compartment if going on a long cross county, however.

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Eddie,

 

So long as the old pump is good I would leave it. It isn't like they blow up. They slowly fail and give you symptoms to know when.

 

Of course, in a failure on Eddie's plane, he doesn't get partial fuel pressure continuing via gravity like we do...but he probably has an aux pump to push fuel past a failed pump until he can get on the ground.

 

Lockwood put the new pump on my plane at annual, but without a fuel pressure gauge I'm blissfully unaware of any change between the two.  :)

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