#fuelpump

In a perfect world, we want to use 100 % fuel with no ethanol. Water will destroy any moving parts or motor especially on an outboard motor. In this video will show you how to diagnose a fuel delivery problem that cause a no start. I hope this video will help some of you out there that might end up with the similar issue... Enjoy guys!

[@theTECHYnewb282]

You sir, are a gentleman and a scholar!!!! This video is EXCELLENT

[@megavega9606]

I’m wondering how many thousands of dollars this has saved how many people

[@theTECHYnewb282]

@@megavega9606 it ended up not being my issue but I was happy that I had a way to rule that out. The FSM/VST is like $1500 if you don't order the individual low/high fuel pumps by themselves

[@megavega9606]

@@theTECHYnewb282 I’m learning all this today for the first time…. What ended up being the issue? I just ordered both low and high pump motors to swap but I have a very similar issue right now

[@theTECHYnewb282]

@@megavega9606 so I think a couple things were happening. I think my fuel system wasn’t venting correctly and maybe that was causing stress on the fuel pump to the point where it was overheating I changed my water pump impeller, fuel filters, thermostat, fuel demand valve and my fuel filler neck that has a built in vent for the carbon canister Couldn’t tell you if it was all or just one of those things lol I just took the shotgun approach and did it all. I was due for a thermostat anyway. I also bought Vessel View mobile for my phone so I can read codes and alarms in the future if anything comes up again

[@GeorgeWashington-bb1zq]

This was an excellent tutorial video! I just installed a low pressure fuel pump on my 2007 Mercury 90hp 4-stroke efi. The additional tips on how to position the pump before placing back in the module was PRICELESS!!! Great job!

[@fwtailchaser3502]

Glad I could help out.

[@phgraves01]

I watch a lot of DIY videos and this video is very well made, step by step and explains the trouble shooting very well. Thank you for sharing.

[@fwtailchaser3502]

Philip Graves Thank you for watching!

[@kennethcranmer5690]

P0

[@markerbuoy]

Thanks for this video. Very calm and collected...thanks for not waving the camera all over the place! I have a 2006 mercury 90hp EFI and foolishly allowed water into my fuel system (don't ask). This killed off my low pressure lift pump, along with other stuff. The local dealer wanted CAN$497+12%tax for a new pump! I installed an after market unit from USAmazon for CAN$62.00. The motor now starts well, runs very well and then dies after 10 minutes or so. I suspect the after market unit cannot keep up. I note your surprise at the cost of the replacement unit. Like you, I think I will have to spend the big money for a pump that works as it should.

[@fwtailchaser3502]

I love to cut my budget on lots of things but when it come to essential parts I don’t! A fuel pump is essentially important, so I would get an originally made part for it. I am just saying….good luck and thank you for watching!

[@markerbuoy]

@@fwtailchaser3502 I'm now reluctantly inclined to agree :-) Again, your video was very helpful, reassuring... Thanks again M

[@terryearlywine5982]

@@markerbuoy I got mine off ebay for a $23.66 High pressure Runs like a champ $400.00 for a different name stamp on it........They all made in china anyways...lmao

[@zeamantedapesca]

Sou do Brasil tenho um motor que teve o mesmo problema do seu a minha solução foi por uma bomba de baixa de 3 bar por fora e eliminar a bóia também da caixa e por um retorno para o tanque. Funcionou perfeitamente

[@michaelcrouch4248]

Thank you for the great video. You are a great teacher and very patient when working 👍

[@fwtailchaser3502]

michael crouch Thank you for the compliment.. I am glad that I can help.

[@davidaverett2314]

Out of every video I researched for days - your video def answered my question on the pump operation!!! Thank you so much!!!!!

[@fwtailchaser3502]

Glad to help. Thank you for watching

[@tomdavies1077]

Want to thank you for the great video I have 2013 mercury four stroke 115 and my fuel pump module just went out 1000.00 later but now I know what to look for. Great video step by step. Thanks again

[@fwtailchaser3502]

Tom Davies I am glad that you like the video and find it helpful. Many video before me had help me as well on many things so I am just trying to give back. Thank you for watching!

[@jackzaxe]

100% SPOT ON!!! I cannot thank you enough as I am back out on the water

[@fwtailchaser3502]

Joel Badanes I am glad I could help as hundreds of other b4 me had helped me. Tight line friend!

[@flyinghighoveryou4872]

Great video thanks for doing this I know it took a long time really good. You help me get back on the water faster than having to wait on my boat repair guy as he was backed up a few weeks!

[@fwtailchaser3502]

Kirk Barnett Nice!!! I am excited for you. It’s a great feeling when you fixed something and fast.....Time to get back out there and fish. Thanks for watching.

[@davidkowalyk3533]

Excellent thorough explanation. Got a 2014 60hp that has the exact symptoms. Good to know what to look for. Cheers

[@fwtailchaser3502]

David Kowalyk ...Cheers...Glad I can help out!

[@ryancantrell6480]

Great vid sir. Thanks for taking the time!

[@wetlifesports]

Thank you! well done! Helps a lot. I have a 2011 90 hp 4 stroke and I think I have the same issue. Just bought the boat and it only had 200 hours. I did a total maintenance before hand, plugs, fuel filters, new gas, oils, impeller, etc, etc. new battery as during my test drive battery was dead, we jumped it and it also was bogging down once we were running. I bought the Smart Craft Vessel view (great unit, highly recommend) before I went to test drive so I could get exact hours. After I got it home I read the faults off Vessel View and it said electrical so I figure battery was issue and battery was definitely bad. Put it in the water for first time yesterday and she ran like a banshee! I though I was 100% then I take it out for a second spin and she conks out idling the canal. I figured I just forgot to open tank vent and so I did and she started again, then dies, over and over, limped it home. Read faults and it complained about Fuel System, Fault 3075-28, "Electric lift fuel pump Timeout", which I found is the Low pressure pump like your issue. I wonder if failing to open vent starved it and it "Timed Out" to protect it? and or she "Timed Out" in death... It idled well when i flushed it but I don't trust it now. I figure since it had low hours it sat a ton and maybe the pump is just gummed up and fried. I am thinking of doing both pumps at the same time including the pressure regulator. I see some nice looking after market pump kits, Walbro brand, that include all 3 units for $220. I am a big believer in OEM but sometimes i feel they are just the same pumps marked up for Mercury. The company Highflowfueldotcom who is selling the kit says they offer better than OEM features and a lifetime replacement warranty, I can't pass it up. I had a recent experience with my Yamaha motorcycle WR250R and its internal electric pump that seized temporarily when it got hot, common problem. I bought an aftermarket one on ebay, Kemso Brand, for $26 and it worked perfect and was made in Japan while my original Yamaha one was made in China, funny reversal. Again, thank you! and I hope my little story help some folks as well. FYI, I have no affiliation to any of these companies, it is just what I found that sounded the best when searching.

[@fwtailchaser3502]

Wet Life Sports Thank you for sharing! Again, I can not stress this enough about fuel/water separator installed right before the motor to catch as much junks from sitting. These lift pumps are so sensitive to Ethanol base fuel that sit around in the tank. The best way to fight this issue is to use fuel stabilizer, changeout fuel filter often and run your motor once a week during down time.

[@devo2k713]

I think your video has convinced me I have a bad fuel pump as well. Aggravating because it starts and runs great then we get in the water and start experiencing sluggish and sputtering behavior. In the past I replaced the gas then had no problem. This year I drained gas and put fresh gas in a week ago and having same problem as last year. Great video!

[@fwtailchaser3502]

I would add fuel stabilizer and run it every 2 weeks if I am not able to use the boat. This way the fuel gets to move around and the pump get running and not get stuck. Thanks for watching!

[@shauno7582]

Incredible vid mate! Super helpful and very well displayed step by step.

[@fwtailchaser3502]

Thank you for watching!

[@clifford202]

Thanks for the outstanding video. My 2011 115 EFI loses fuel pressure, down to 25 psi, should be 50. Doesn't do it all the time. I'm replacing both pumps and float switch. Thanks again.

[@fwtailchaser3502]

clifford202 ....Glad I can help!

[@kristievanthul7086]

That was a great video,you did a real solid job troubleshooting the fuel delivery.just a mental note,loose the watch when swinging wrenches,small amount of atf on seals for lube,and a tug with pliers on zip ties to tighten,air isn’t your friend unless your holding you breath.thank you for sharing.

[@fwtailchaser3502]

LoL.....knock on wood I still have the watch! I need to remember to take it off next time....Good observation though. Thank you for watching.

[@apackwestbound5946]

Thank you for all the effort you put into your excellent video. - Respectfully

[@fwtailchaser3502]

I appreciate your compliment sir! I love it whenever I can help, just like others that had help me b4.

[@Hendox4Vikes]

Amazing video, can't. Thank you enough. I was not able to get to bottom bolt but then realized you van also pull top while leaving casing in motor and the bottom two hoses don't need touched either then. Thanks!

[@fwtailchaser3502]

Glad I can help brother!

[@johngriggs3379]

Excellent video. Thank you !

[@marcoponcedeleon2593]

thank you for posting> Rocky Point Mexico!!!!

[@fwtailchaser3502]

You welcome, glad I can help!

[@boonleano8315]

Thanks buddy, well presented video. one of the best i have seen ...

[@fwtailchaser3502]

Thank you!

[@Kingoftheharbor]

Great video I’m having the same problems with my 2012 Mercury 115 4stroke thanks

[@fwtailchaser3502]

Glad I can help👍🏼....! Tight line Jimbo.

[@birdd99]

very well done video , this will help me a lot , thank you

[@fwtailchaser3502]

Great, I am glad that I can help out.

[@rickkelley8602]

Good job. Waiting for the prop repair next.

[@fwtailchaser3502]

Rick Kelley Nahh!! It’s still going good no need to repair it. The next time anything happened..It will be a stainless steel prop...:)

[@hc130p]

Excellent...great video!

[@fwtailchaser3502]

Thank you for watching!

[@jimthompson129]

Excellent video!!!! Thank you!!!

[@fwtailchaser3502]

Jim Thompson ....No problems!!!! I want to make more fishing video but with all the boat issues suck up all my times...lol. You should go check out my previous video in regards to my boat bunks. Thanks!

[@waypro4286]

Awesome video, thank you!

[@fwtailchaser3502]

waypro....I am glad it was useful !

[@huele9553]

Great job bro! this works for my 75HP too!

[@fwtailchaser3502]

I am glad that I can help out! Thanks

[@a253383]

Great video! Thanks!

[@fwtailchaser3502]

I am glad you like it! Thanks

[@GregGoss82]

Thank you for a great video. With little mechanical experience your explanation on how the high and low pressure pumps work I think I'll try to take care of a fuel issue that my boat is having as well. I just got a 2012 Mercury 40 HP 4 stroke. Before I got the boat It set up for a couple of years and after changing the fuel, batteries and checking the oil and Spark plugs Its gives me 6 beeps(critical status) when I start it and dies pretty quickly after. The manual says to take to the dealership but I think before I spend a 1000 dollars at Bass Pro I'll be taking my fuel module off and check this my self. Thanks again. I'll let you know how it turns out.

[@fwtailchaser3502]

Gregory Goss ....Yeah man, go for it! I would use the jumper wires and hook it up to the car battery and see if it turn. If it doesn’t do anything it’s bad; but if it’s even turn just a little then you know it’s good. It’s just stuck due to sitting for a while. I would go to the part store and get me a gallon of part cleaner and soak it overnight. I would then try to hook it up again and this time try to reverse the polarity back and forth to free up the turning shaft on the inside of the fuel pump. This will work every time! Good luck brother.

[@johnzillah]

Thanks for the video. I have the 2008 version of this motor. Mine seems to run fine and then I hear 4 beeps before it starts running rough. I was thinking it was one of these pumps but your video makes me think I need to replace those filters in the lines. Thank you again

[@fwtailchaser3502]

Definitely check your inline filters! There will be two of them...one on the lower fuel line and one on the high side. I also add a fuel/water separator in between the tank and the motor to catch any gunk and or water. Running rough could cause by bad fuel and its a precursor to disaster. I will also add a bottle of fuel stabilizer every time I fuel up. Thanks for watching...tight line.

[@johnzillah]

I have the fuel separator ordered and hopefully it will be here before the weekend. I ordered the two filters but for some reason the filters I received are very small compared to the ones on the motor. West Marine gave me the part number but they are definitely not the ones needed. I am going to try and narrow that down today so I can have the boat out on the Pamlico Sound this weekend. Thanks again!

[@fwtailchaser3502]

John Bobbitt Nice! I used to fish in Nags Head a lot when I was still in N Carolina...Good luck!

[@johnzillah]

I swapped out the fuel filters and it fixed my problem. I will be adding the fuel separator next for extra protection. Thanks again!

[@Core3DTech]

Mine is a 90hp but looks identical to yours. I ordered the FSM repair kit and hope to repeat what you did here. Thx!!

[@fwtailchaser3502]

Glad I can help!

[@Core3DTech]

FW tailchaser turned the float switch was the problem. Should have replaced it while I had it open

[@fwtailchaser3502]

Core3D_Tech I believe it, ethanol is good at sticking to anything that’s not moving for a while. I find that the best way to combating this is to run the motor for about 15 minutes every 3-4 weeks!

[@frankbloom5565]

Well done video thank you

[@fwtailchaser3502]

Frank Bloom Glad that I can help. Just like hundreds before me had help me out. Thanks!

[@johncarpenter1476]

Thank you, well done. My problem was that my recently bought 2011 Mercury 115 hp 4-stroke started fine but engine would 6 beep and shake around 2200-2300 rpms (as if it wasn't getting fuel). It would stop when I put the throttle in neutral or turn off ignition. I saw another YT in which the author said Mercury is notorious for bad float switches in similar motors. I pulled & disassembled the FSM and tested the components. The pumps ran fine but the float switch showed no continuity (OL) when Ohmed either way as suggested in service manual. Also noticed that the current float switch showed a 2014 manufacture date although the engine is a 2011 - meaning it's been replaced at least once. Tested and installed a new float switch and will be doing a water test tomorrow. Crossing my fingers - engine only as just under 400 hours...Always serviced, etc.

[@fwtailchaser3502]

I Will keep my fingers crossed as well. I hope everything go smooth for you tomorrow. Thanks for watching.

[@johncarpenter1476]

Unfortunately same problem - starves itself for fuel around 3000 RPMs in water, shutters, 6 beep guardian mode. Runs fine idle speeds up to 2500-3000 RPMs. I had pulled FSM - pumps ran fine on 12 volt test. Tested and installed after market float switch but same problem. Did notice that high pressure fuel filter to FSM becomes nearly empty during high RPMs before shutting down. Wondering if after market float switch might be an issue. ? A mech said they can ohm test fine and still be faulty? About to pull my hair out! No good Merc techs in my area...

[@fwtailchaser3502]

Not really sure without laying my hand on the problem but could could very well be the high pressure pump!

[@johncarpenter1476]

Thank you to everyone for responding. Everything pointed to the FSM but pumps tested fine on 12 volt (float switch was inconsistent, so I replace but still had problem) When I first had the problem, it was after a flawless test ride before buying it AND after I replaced a thermostat that was working but looked like it had not been replaced in years. After much reflection, my wife asked me what I did to the engine after we bought it...? The only mechanical thing I did was install a NON OEM thermostat from GHHG Amazon! Cheap China crap! So...I removed and tested it and it failed - was stuck closed, opened in hot water but you could then easily push the rod in and out without much effort. Therefore, it was stuck closed some time after I installed & ran it for our first time (problem started within half a day of use). I researched thermostat failures and learned that Mercury 4-strokes will idle/troll speed fine but go into 6 beep guardian mode upon acceleration on stuck closed thermostats so the engine doesn't overheat. It happens around 2300 rpms under load and 3000 rpms on the trailer w/hose. Mercury parts on back orders due to supply chain issues, so removed a thermostat I knew worked off another boat/Merc engine I had and installed it. Now the engine revs on trailer 45-4800 rpms perfectly! I should mention that I replaced the main fuel filter going to the FSM as well...POINT is that a stuck closed thermostat will 6 beep, shut down engine like a FSM problem. Fact is that the shut down starves engine of fuel like a FSM issue....Make sure you use OEM parts and replace those thermostats every year in salt and every other year if fresh water....Again, thanks to all for the responses...

[@fwtailchaser3502]

@@johncarpenter1476 Wow, I bet you can sleep well now that the problem is fixed! That was a good hunting game for sure. It’s definitely a new lesson learn for me. Thanks for sharing. See you out on the water.

[@adl2005]

This is a good vid, why do people dislike and thumbs down it?????????????

[@fwtailchaser3502]

AD L200 Thank you! There are some that are just happy to be alive and some just not happy no matter what! Every video take times, lots of effort and thought into making it.....But to some are just simply not enough I guess. Thank you for watch!

[@mikepaul777]

The only thing I would have done different is checked the new one before installing. But good job.

[@fwtailchaser3502]

Great idea!

[@handtohandcombat3535]

Good job bud. I think I have this same issue on my 250.

[@fwtailchaser3502]

Thanks for watching!

[@dougbawden4321]

Excellent video. What happens if the seal on the top of that housing/lid is bad?

[@MandrakeRoots]

Thanks for the upload...tackling this project tomorrow...had a deteriorating grey fuel line that filled low pressure fuel filter with plastic bits... changed line and both filters...nothing changed...idles fine, then put on water at high rpm and a load, feels bogged down then stutters and stalls, starts right back up and sounds like it's being starved of fuel. I did notice that the fuel filters had very little fuel in them, I would think they would be filled. 🤞 I hope this is it, and hope I can free it up... those pumps are pricey.

[@fwtailchaser3502]

Sorry for the late response but good luck!

[@MandrakeRoots]

@@fwtailchaser3502 Thanks for the reply...I disassembled the fuel module and everything seemed good...SMH...then decided to go back from from tank to motor...the new grey line I put on ended up being the problem again...when I pushed it onto the barb, the inner liner of hose collapsed causing a clog. I got lucky and put a smooth center punch in hose then heated it to form to larger diameter. I did end up buying 2 new fuel pumps since the ones are the original 2008 ones...summit racing had the best price, like $70 a pump. Just get part number off old ones.

[@fwtailchaser3502]

@@MandrakeRoots I would change out all my gray fuel line! Never gray fuel line on any boat (bad luck). Thanks for sharing.

[@vaughnspence8366]

Excellent video. I have the same problem with my 115. Less than 100 hours. WTF? I heard that they suggest you replace both pumps because there is a high probability that the 2nd pump will face shortly thereafter. Two guys I know change the high pressure pump and then 3 weeks later had to change the low pressure one.

[@fwtailchaser3502]

Not sure what happen but you know there is always flaws in building anything! I am keeping my finger cross on the low side but so far so good. Thank you for watching

[@jones1394]

I have a 90hp 4 stroke keep blowing the 20amp fuse. Do you think it might be the high pressure feul pump. Once the fuse is blown, it will not start. Brand new 2016 at the time. I let it setup a long time.

[@MrTruth7788]

Great video. Question : my 2012 115 EFI starts and runs good up on plane ! When throttling down begins to shudder and alarm starts beeping ( maybe 4-6 times)??? You mentioned about running on two cylinders sometimes? There’s a float switch in that FSM tank that are known to act up ? Any ideas anybody ???

[@fwtailchaser3502]

The possibility is endless, faulty float switch, low pressure on high side fuel line, restriction flow in the injectors…and on. Look up the beep sequence for your model and start there.

[@mccallumcra]

Thank you

[@fwtailchaser3502]

mccallumcra ...Glad I can help! Don’t forget to subscribe for future videos of fishing, traveling and DIY projects....Tight line guy!

[@mccallumcra]

@@fwtailchaser3502 how about adding a drain line to the bottom of the tank so when I fills up with water it can be drained.

[@fwtailchaser3502]

mccallumcra ...You can add a fuel/water separator filter after the fuel tank and before the motor to catch all your water.

[@kajbyman3006]

Do anyone have any idea what the high pressure should be?On my -09 100hp i have power loss and missfiring over 2000rpm..The collector tank was full of gas when removed,so the low side is working..

[@adam1556]

My mercury seapro 115 starts stuttering at 3500-4000 RPM. I have changed all fuel filters but no change. Please help.

[@majormegapix]

Great video. I'm going through a similar issue with my 2012 merc 4 stroke 115. It would run rough and would not accelerate over 4000rpm. I was thinking bad wire/plug or coil. The shop actually ordered a coil for it but was not the fix so now they're checking the fuel system. Could be a delivery problem like yours. I'm hoping they can diag soon cause I want to get back out! Wish I was more of a tech like you!

[@fwtailchaser3502]

megapix I wish you the best of luck and get out on the water soon. It was just getting too expensive for me every time I bring it to the dealer and the waiting to get the boat in is just annoying . Thank you the compliment!

[@mrbmp09]

I would seriously find a different shop.

[@solden49]

So I have a 2014 mercury 90 that look exactly the same. But I have gas getting into my oil. You think it would be one of the fuel pumps diaphragm leaking?

[@fwtailchaser3502]

It could be one of the possibilities!

[@solden49]

@@fwtailchaser3502 Thank you!!

[@1fede100]

Tubazione interna !!!!

[@brianreardon553]

Did you need to disconnect battery before you start?

[@fwtailchaser3502]

Sorry, I don’t understand what you asking?

[@bradstout3067]

How difficult is it to change out the fuel line?

[@fwtailchaser3502]

Brad Stout Fuel line to where? Is it from the tank to the motor, from the lift pumps to the motor? Regardless where, it’s not that hard. Just be sure to tighten the new line to the old line so you don’t have to fish for it later.

[@michaelhiers9457]

Where is the FSM on a 2016 mercury 115

[@zeamantedapesca]

Problema crônico desse motor 😢 Resolvi colocando uma bomba externa de baixa e eliminando a bóia

[@davemilster]

Why does Mercury indicate that you have to purge the fuel line system when obviously your system was dry? I changed fuel line on my 115 mercury 4 stroke turned on the key to let the pump run. Then when starting It would only fire on one cylinder. then the bottom cylinder flooded/filled with fuel. I removed the plugs and siphoned a cup out of fuel out of thus cylinder. Wasup with that? Injector stuck open? Why did the other cylinders not fire? It’s at the dealer now. $$$$$ agh

[@fwtailchaser3502]

It’s really hard to say, many possibilities..Bad injector(s), plugs, stuck fuel float and on...! I would love to know what happened when the dealership get back with you. Please keep me posted. Thanks!

[@Bouba07]

When you put the key on you should not hear the pump making his cycle??

[@fwtailchaser3502]

You should hear a quick self check hissing sound yes.

[@Bouba07]

@@fwtailchaser3502 I think mine is timing out...I hear the hissing but it longer than usual...but I hear both pump turning...

[@fwtailchaser3502]

@@Bouba07 If it does not stop, you must have a bad switch or even pump

[@shawnb_fishing1534]

What is that you used to test the motors?

[@fwtailchaser3502]

My car battery!

[@shawnb_fishing1534]

@@fwtailchaser3502 🤣🤣 that tester deal that had the probes…?

[@fwtailchaser3502]

Oh, it’s the Fluke multi meter that measure voltage, amperage, etc.

[@NANDOALLAN]

Im have same problem mercury delar tol me pump 332 dollar , Im but same one same manufcture for 75 dollar online

[@fwtailchaser3502]

The dealer always charge too much! I hope this video will help you some.

[@naseerhassan9161]

Model 2019

[@fwtailchaser3502]

naseer hassan you are weird man!

[@jbettss]

those pumps are alot cheaper than 300 new on ebay or amazon.

[@fwtailchaser3502]

I had bad experience with ebay in the past and did not care much for amazon. I knew it was not the cheapest with iboats part but I like their customer service. Thanks for watching!

[@andyta614]

Why the sunglasses? Its not even that sunny!

[@fwtailchaser3502]

Andyta614 ....To see through your soul....lol

[@jbettss]

Great video. Where did you order the pump?

[@fwtailchaser3502]

jbettss ......iboat.com

[@jbettss]

FW tailchaser Thank you. You seem very knowledgeable with engines. How did you figure out how to take everything apart?

[@fwtailchaser3502]

jbettss.....Oh, I went to mechanic school back many moons ago and work for Nissan for 6 years. I am also a cheap mother and that in it self is a big motivation to fix anything b4 I send it off for the pro....lol! Ok, the truth is... a little mechanic background, lots of reading ( boat forums), KZbin videos and ask questions. I am also one of those guys who would tear things apart just to see why it works the way it is. Whenever I take things apart, I work slow and try to memorize how it come off and when it goes back, just the exact opposite orders. You can do it too. Thanks!

[@naseerhassan9161]

I know the place of fuol Bambi

[@fwtailchaser3502]

naseer hassan What are you saying man?

[@naseerhassan9161]

Ingaen

[@fwtailchaser3502]

naseer hassan What???

[@Aswet485]

Fabulous video, I’m comfortable I would be able to replace a pump now. But before I start that decoupling stuff, my pump is running for 5 seconds as always when I turn on the ignition. Isn’t that both a proof that the low pressure pump is working as well as the floater able to signal that the pump housing is full? I get my engine to run for many minutes when pushing fuel into the hoses. But the suction seems to suddenly drop. Here is how it sounds. Greatful for any advise 😢 kzbin.infovb2xcQJbOoE?feature=share

[@PuulanSaunamoguli]

Float switch and its status (position) is mainly to tell the PCM what is the fuel level WHEN ENGINE IS STARTED - KEY ON -position. When engine is running, PCM orders LP pump to run according to how much fuel has consumed (grams) in that cycle.

[@PuulanSaunamoguli]

So if the float switch is stuck or the switch is not electrically sending the information correctly, PCM does not put the LP pump on and the module does not have gas. Also, it doesnt consume the gas which would lead PCM to order more gas because there is nothing to consume. This type of an error in float switch is not given in smartcraft.

[@Aswet485]

@@PuulanSaunamoguli thanks! I do have tested both LP and HP pumps outside the fuel module and both seems fine. I did find a broken seal on the HP pump which I thought was the root cause. But after replacing it, the symptoms just changed. Now the engine runs mostly fine on idle, but struggles over 2000 rpm. I can also see that it’s stops sucking fuel. So I’m looking for reasons for that. When inspecting the floater switch, it’s definitely not stuck, but have not found a way to measure it. Now I’m trying to figure out how to measure the performance of the LP pump, it’s as you say, to expensive just to replace.

[@PuulanSaunamoguli]

@@Aswet485 so I changed now the float, hp pump and both fuel filters. The problem remains the same. Have you had any success on yours?

[@Aswet485]

@@PuulanSaunamoguli still struggling. The problem is for sure that it stops sucking fuel after a while. I have been able to run the engine for half an hour in variable speed (at sea) without any issues. Then when I satisfied when into to port again, it’s started coughing and finally stopped and was not possible to get started again. I do know that pumping fuel in manually keeps the engine running. What I’m not sure is if the LPF runs smoothly and then stops or if it’s not running at all. Looking for an easy way to monitor that. I have a feeling that the pump is shut down by another signal. Like a stick fuel level switch and vent canister switch kicking in. Just a struggle to figure out without diagnostic tools.

[@danikboudreau6702]

e

[@danikboudreau6702]

yassssssssssssssssssssssssssss

[@danikboudreau6702]

yasssss