Stumped - Fuel Delivery Issue

fpc310
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Stumped - Fuel Delivery Issue

Post by fpc310 »

I am most definitely stumped.

Here are the facts:
The anti-siphon check valve is good and working properly.
I am able to easily manually pull fuel from suction hose just before it goes into the fuel pump.
I have no fuel being delivered past the fuel pump.
The final fuel canister filter was replaced today
The fuel water separator filter was brand new, replaced today.
The fuel pump was brand new 4 engine hours ago

So.... my thought was the fuel pump has gone bad. No luck. I replaced it today with a new in box spare and still no fuel suction or fuel pressure. The fuel water separator filter is empty.

What am I missing? Thanks for the advice.
Todd
1983 32’ SedanFlybridge
Twin 318 Chryslers.
Marblehead, Ohio
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Busia
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Re: Stumped - Fuel Delivery Issue

Post by Busia »

Sounds like you have the wrong fuel pump.
BUSIA
located in Ketchikan, Alaska. Gods country
32 foot Marinette (no fly bridge)
twin 350 Crusader (Chev 350) engines
1:1 Borg Warner velvet drive transmissions
Closed cooling (antifreeze in the engine)
Proud to be retired IBEW and an A+P
thepaintman
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Re: Stumped - Fuel Delivery Issue

Post by thepaintman »

Had same problem with New engine this spring. I overlooked the shut off between water separaters. Closed it to change filters...
69 River Cruiser houseboat
Twin Chrysler 318's
Hydraulic steering both stations
All new wiring ac/DC
New chargers, galv isolator
Running Erie Canal from mile 240.3
thepaintman
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Re: Stumped - Fuel Delivery Issue

Post by thepaintman »

Also the arm on pump can be installed on wrong side of lobe. If that is the case, it will have wear Mark on top side of arm. Most of what I know about boats I learned from drunk people the internet. The rest, trial and error.
69 River Cruiser houseboat
Twin Chrysler 318's
Hydraulic steering both stations
All new wiring ac/DC
New chargers, galv isolator
Running Erie Canal from mile 240.3
fpc310
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Re: Stumped - Fuel Delivery Issue

Post by fpc310 »

Definitely not a shutoff, but the pump may be installed wrong.
Todd
1983 32’ SedanFlybridge
Twin 318 Chryslers.
Marblehead, Ohio
Fastjeff
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Re: Stumped - Fuel Delivery Issue

Post by Fastjeff »

I'm assuming this is a Chrysler 318 or 360 engine. If not, ignore the below.

The cam that runs the fuel pump bolts to the front of the cam with the drive sprocket. If this has cam come loose somehow, or the key is striped, then the cam will not operate the fuel pump correctly. Unfortunately, to see if that's the case you'd have to rip off the front of the motor--a long and nasty (but do-able) job.

Good luck.

Jeff
"We live at the bottom of an ocean of air, not at the top." General Marvage Slatington
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bcassedy
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Re: Stumped - Fuel Delivery Issue

Post by bcassedy »

Just to eliminate ANY kind of obstruction issue I'd recommend:
Prerequisite - if your system still has the Perko ceramic filter in place, this should be drained, cleaned out, & CAREFULLY filled with clean fuel and screwed back into place.
1. disconnect fuel line at tank (anti-siphon valve remains with fuel line). Fit clear hose tightly over gas tank fitting. Try pulling fuel up and out of tank. Clear hose will let you:
- not get a mouthful,
- see if it's easy to pull fuel from tank ** no obstruction
- see (inside of hose <use a decent length to allow what is at bottom of tank to make it up into hose> if tank loaded with gunk at pick up tube's bottom>)
Everything good? Next step...
2. Disconnect anti-siphon valve from disconnected fuel line.
- check for orientation (not mounted backwards (if that's possible?) which would definitely prevent fuel getting from tank!)
Clear? Remount to tank (fuel line from tank still disconnected.) Connect hose used at fuel tank to this end of fuel line.
3. Disconnect fuel line from inlet side of fuel/water separator. Connect clear hose to this end as well.
Place end of clear hose at fuel tank line in clean/clear jar and secure so it won't come out of jar -OR- jar tip over. Blow into fuel/water separator end hose. You should get something coming out of fuel tank end hose. Since you cleaned the Perko filter earlier anything that's not clean fuel was in the fuel line.
If all the above are completed successfully,
(You can now reconnect fuel line back to inlet assembly on tank and inlet side of fuel/water separator)
You now have the following to check:
A. Fuel delivery from inlet side of fuel/water separator thru that filter to inlet side of fuel pump.
- the "blow" test from above can be used from outlet side of Perko filter to inlet side of pump - disconnect fuel line at Perko outlet (easier to get to and fit hose to), connect hose. Connect other hose to line at inlet fitting of fuel pump. Place hose end in jar and secure. Try blowing air at Perko end. You should be able to easily blow air thru line and see gas (gunk?) in jar.
Clean/clean? Next step...
B. Pull hose from Perko and reconnect fuel line at Perko and inlet side of fuel pump***
*** as mentioned earlier in posts, it might be that the arm of the fuel pump might have been installed such that the engine lobe that rotates against the arm is doing so incorrectly. Now, with the inlet side of fuel line disconnected, would be a good time to disconnect the outlet line, pull the fuel pump and see if the wear Mark's are where they should (pump arm rubbing against line in correct fashion). Didn't which engine is affected..
-> port? - easy to shine flashlight into pump arm hole in engine and see cam that fuel pump arm runs against.
** if you can't easily see cam, or you want to check that it's rotating, you can (after disconnecting center distributor wire so engine won't start) bump the engine to check cam's positioning.
-> starboard -> :-( tougher but doable using an 'in place' (ie. light with a clamp to allow hands free use) light and mirror (selfie stick type) if you can't maneuver over engine.
- after confirming pump placement correct, connect hose to outlet line of fuel pump. Disconnect line at carb, connect hose to this end. Perform the 'blow' process from fuel pump outlet side of the pump line to the carb.
... Ok? Then check the inlet port of the carb. There's a screen there that can be removed carefully and cleaned.
--> reconnect fuel lines at ALL connection points.
After performing (successfully?) all the above, you've eliminated 99% of obstruction possibilities. The remaining 1% could be at the carb itself in the ports of the carb. If not an obstruction, then a mechanical issue (fuel pump - such as Jeff mentions above) is just about the only remaining possibility.

PS - I tell you all of the above because I had to do it last year on the starboard engine. My issues resulted from having left the starboard fuel tank cap off, rain getting in the tank :shock: . I tried pulling out the gunk (got about 2 gallons) but the damage to the fuel (ethanol gas - don't ask... :oops: ) had been done. Ended up giving away 60 gallons. Other issues turned out to be a bad fuel pump - tried installing an electric one <with a oil sending switch that is required), a momentary switch to prime and keep engine running till oil pressure activated the new switch throwing a relay that activated the electric pump normally. Had thought mechanical pumps for our engines were no longer available - WRONG! Andddd to top it off, the existing carb was so corroded from letting ethanol gas sit in it over a number of winters it couldn't be rebuilt so it had to be replaced. Major expensive lessons!! :o

Bill
Bill & Sharon Cassedy
"Sunset Seeker"
'88 32' Sedan Bridge to be sold (updtd 1-1-22)
"Sunset Seeker Too" (SS2)
'88 41' Marquis hardtop. (as of 1/1/22)
Located in Aurora, In.
Always fresh water.
fpc310
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Re: Stumped - Fuel Delivery Issue

Post by fpc310 »

Thanks for the feedback. The brand new fuel pump was tested and it’s definitely bad after 3 hours of use. With the new fuel pump, I’m wondering if running the carb dry and also replacing f the fuel / water filter (and having that dry) is too much air for the pump to overcome to achieve a good prime. I’m wondering if I need to manually pump fuel through the system to give the new pump a head start.
Todd
1983 32’ SedanFlybridge
Twin 318 Chryslers.
Marblehead, Ohio
Fastjeff
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Re: Stumped - Fuel Delivery Issue

Post by Fastjeff »

The pump will achieve prime if you dump gas down the carb to get the works going--an ancient method for carbs and fuel pumps.

Now, if you STILL are not getting fuel to the carb, then the problem is still not solved. I would suggest adding a Tee and a fuel pressure gage to the carb to see if the pump is making pressure--you're looking for about 5 psig.

Now, If there's pressure there, but no gas in the carb, then there's a restriction at the carb. (Had that happen to me once--the inlet filter in the carb was lode with crap.)

If there's no pressure there--and you've already established the fuel is getting to the fuel pump--then something is keeping this new pump from operating.

Good luck!

Jeff
"We live at the bottom of an ocean of air, not at the top." General Marvage Slatington
ddependo
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Re: Stumped - Fuel Delivery Issue

Post by ddependo »

Todd, you didn't say what kind of fuel water separator you have , but if gasket is loose or missing it will suck air instead of fuel.
good luck
Wayne
1973 32 express fly bridge
Chattanooga
"Southern Lady"
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