2006 DF250 fuel starvation problem

[j a casas]

My 2006 DF250 started dying on me after running for about 20 minutes. I can re-start it by pumping the bulb, but it quickly starts to die again. after awhile, it dyes at a faster rate. All fuel filters where replaced, and running from an external tank still produces the same effect. My guess is the low pressure fuel pump is defective, has a small leak or it does not work as a check valve to hold the fuel in the line ?
It seems to start and run when I re-pump the bulb, so I suspect the high pressure pump works as long as there is fuel in the bowl. WHAT DO YOU THINK ?

[artdf175]

easy to check the low pressure pump but that is one of the least problems we have . take the hose off the side that goes to the HP pump. put a hose in a container and turn the engine over a few times and watch for fuel.
however, check your system for a air leak from the fuel bulb to HP pump.
pump up the system and run it
watch the small inline filter and my guess it will full up with air.
Art

[j a casas]

Good place to check for air, I was using an in-line filter after the bulb, but it only checked up to the bulb. Will check tomorrow, but if no air, should I prime the bulb, or let the pump work to see if it sucks fuel ?

[briscoe]

Sounds like an air leak. Not sure why it would repeat issue with external tank, though. I had a lot of issues with bulb going soft and I didn't have the water separator on tightly. It was barely hand tight. Afterward, I have only had a few bulb issues when it's 100° outside, I need to pump bulb occasionally.

[j a casas]

Yes, there is small quantity of air in the Low Press filter, it goes partially away when I pressurize the bulb, so it is not coming from the bulb. I will run it with external tank one more time and keep a look on the LP filter.

[artdf175]

If the bulb is as old as the motor, it could very well be the bulb. I had this problem last year -2006- version and even though the crips on each end look right, they were not and by pulling on the ends, sure enough one just came apart in my hands.. replaced bulb and no more air leaks.
Art

[j a casas]

Update: Have installed external tank with new bulb and line directly to the inlet of the low pressure filter, have pumped and filled the line and have purged air from the evaporator and high pressure pump box. the motor will run for about 20 minutes at 1000 rpm (trying to speed things up) and then it dies when the high pressure pump starves from low fuel. Next Tuesday I will change the main low pressure pump filter, although it looks ok from the clear base and it only has 350 hours total on motor. I am still wondering if the low pressure pump is not bad, but at $477.00 cost, I will try other things first. My original trip to the mechanic cost me $800.00 for changing all filters and check valve in the evaporator. It did not solve the problem, but I did not take back to mechanic because the fix was done before the pandemic and I had not fully tried it out on the water until this year.

[artdf175]

do you have the full service manual?
have you checked the float valve in the evaporator for yourself?
If it is not set correctly and shuts off the fuel you will empty the VSP.
Did you try the suggestion on checking the low pressure pump?
this last 20 minute run -- confirm that the pre- fuel filter was not showing air bubbles.
there are only a few things that cause the VSP to empty
check them 1 by 1
Art

[j a casas]

I have a fairly good manual downloaded from internet.
I did not check the VSP as the $800.00 job consisted of inspection and filter changes in the VSP, looks that only filter not changed was the Low Pressure pre filter and it looks OK thru the transparent housing. I ordered a new one anyway, and will change it as soon as It arrives.
I will disconnect the discharge of the low pressure pump and check for flow next, but I was putting this off for last as it seemed more fitting to check with a pressure gauge installed and I do not have one available (also being lazy as it looked a bit hard to get at).

[artdf175]

the pre- filter should be the least of your problem check list unless it is cracked.
one thing I missed earlier is the fuel tank vent.. lots of problems in this area.. most visible problem is the primer bulb collapses as the fuel pump creates a vacuum to the point no more fuel will flow.
here is a rough order That I would suggest:
1 - air in pre-filter ...if any- should go away when running and no air should return // my engine - pumped primer bulb and filled up filter then as soon as engine started you could see bubbles and fuel level would drop until it was sucking in air//
any bubbles - find source of air leak.
2- If #1 not the problem - take the hose off the 'out' side of the low pressure fuel pump- put a short piece of fuel line and put the end in a quart jar- turn the engine over and you should have a good flow of fuel..
3. since you had HP pump serviced .. recheck the float.. it is very possible it was not assembled correctly or not adjusted correctly... It can cut of fuel flow completely.. there are a lot of posts that deal with the opposite.. being out of adjustment the other way allowing fuel to overfill and then dump into the oil pan.

Those are the 4 things that i can suggest
Art

[j a casas]

No problem with the fuel vent, tried various tanks.
1.Small amount of air goes away on the pre-filter, stays full.
2. Low pressure pump seems to have good flow into jar, did not check pressure, but flow was plenty.
3.Gave up on testing and made appointment on Thursday to take back to the mechanic ($800.00) he mentioned high pressure pump, but I think this not to be the problem, as engine runs good as long as there is fuel in the VSP. This problem started before the VSP and filters where checked, I would expect float would fail open not closed ?
I will bite the bullet and let you know what he finds.

[j a casas]

Well, I canceled the appointment with the repair shop, I am too old to put up with bad attitude from the owner. I went to another Suzuki dealer closer to my house and would be very happy to work with them, except they have a 2 week backlog, so in the meantime I rigged a makeshift pressure gauge and tested the output of the low pressure pump. The pump pressure is zero. therefore my next step will be to check for voltage, but I am finding disconnecting the plug a bit of a challenge. also have not check for the pump fuse location yet. Will keep you posted once I figure out how to unplug the connector.

[j a casas]

Checked voltage to low pressure fuel pump and there is no voltage to the pump. My next challenge will be to find the fuel pump fuse and why there is no power. There has not been any electrical work done to this engine with only 350 hours, only the computer has been changed under warranty do to a Suzuki recall.

[j a casas]

Problem found - The ECM is not sending power to the low pressure pump.
This ECM is new (replaced under factory recall) with maybe 3 hours used to troubleshoot the problem. Suzuki will not warrant unit because problem was discovered by me after warranty period. However this problem was sent to be repaired at the Suzuki dealer during warranty period, the dealer charged $800.00 for unrelated repairs and declared the problem solved. Due to marinas being closed and other family complications due to Covy 19, this boat was not tested until after the warranty period. This should have been properly diagnosed and repair by the dealer, but Suzuki claims that it has no control of their dealer as he is an independent business entity and therefore refuses to honor warranty. this dealer is not being very cooperative and I am stuck with a considerable loss. These ECMs list for around $1500 at Suzuki, my old one was working fine.
PS dealer installed the wrong ECM originally and later came to my home to replace it with a different model in order to avoid extra charges from Suzuki.

[Handsomerob1980]

Try finding a new dealer and explain the situation and assure them that you plan to do all your business with them from this point on if they are willing to help out. Even if they sell you the ECM at cost? Shitty situation. Dealer I'm dealing with will ship me the parts for free under warranty to install myself and then ship the defective part back. Find a good dealer! Hope you find a solution.