DT140 - not running - trashed fuel pump?? (Update - Pump ok...still no go)

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jct2005

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1998 DT 140 EFI. Enging new to me. First time out ran well for less than hour. Then started losing power and then died. Good prime the bulb and get a few seconds of idle out of it. Now oddly it seems like it will run longer in reverse than forward after some priming (how i got it back to trailer). 20 to 30 seconds before bogging down and quitting.

Pulled the fuel filter and the vapor sep filter. Both clean. Pulled apart the fuel pump. Pic attached of the findings. The diaphragm closest to the engine was intact but looked blistered on one side. Also, one of the clear plastic valves was broken as pictured.

Questions:

1. the pump obviously needs rebuilding, but would this be the cause of the symptoms described?
2. is this just an age related issue or would there be another cause for this type of failure?
3. the diaphragm rebuild kits i've seen only include the spring and diaphragms, not the clear plastic valve. I'm thinking i need a new pump assembly. Is that correct?

Thanks everyone in advance.
Curt2010-06-07 20.19.07.jpg

2010-06-07 20.16.46.jpg
 
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timster

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Re: DT140 - not running - trashed fuel pump??

Re: DT140 - not running - trashed fuel pump??

The motor should also have a electric fuel pump on it. I would look into that as well. If i remember right is sits in the front of the motor under the intake and throttle body.
 
J

jct2005

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Re: DT140 - not running - trashed fuel pump??

Re: DT140 - not running - trashed fuel pump??

Timster,

Thanks for the help. Any specific procedures for testing the electric pump? Thanks
 
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timster

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Re: DT140 - not running - trashed fuel pump??

Re: DT140 - not running - trashed fuel pump??

I'm not sure how to test the electric fuel pump, but I do know that they have both a mechanical and electric fuel pump for the EFI. It does look like you need to rebuild the mechanical fuel pump. So, I would fix that and see if it fixes you problem. Then if it still doesn't run i would look into the electric fuel pump.
 
J

jct2005

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Re: DT140 - not running - trashed fuel pump??

Re: DT140 - not running - trashed fuel pump??

Consensus is that a new fuel pump is the order of the day BUT they are back ordered everywhere with no hope of getting one in!!!

There is nothing wrong with the pump (after new diaphragms) other than those clear plastic valve things (still dont know the names of them). Does anyone know if i can get these some where and just replace those in my pump????

Im stranded until then.......please help!!!
 
Marion Moore

Marion Moore

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Re: DT140 - not running - trashed fuel pump??

Re: DT140 - not running - trashed fuel pump??

Try the parts look up on the Browns Point Marine site. Call them to see if they have what you need in stock. If all elase fails I have a used one and used high pressure fuel pump I could sell.
 
9

99yam40

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Re: DT140 - not running - trashed fuel pump??

Re: DT140 - not running - trashed fuel pump??

They are check valves.
the pump part # 15100-9491V shows for 1986-2001 DT115 & DT140
where all have you checked for parts?
Maybe you could make the check valves if they are removable
 
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jct2005

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Re: DT140 - not running - trashed fuel pump??

Re: DT140 - not running - trashed fuel pump??

Checked local dealer, Babbits, Browns. Browns says they're on national backorder. Going to try and pull some check valves from different pump and cross fingers.
 
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jct2005

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Re: DT140 - not running - trashed fuel pump?? (Update - Pump ok...still no go)

Update on the saga:

Replaced the low pressure pump. Another test ride and similar (but not identical problem). This time idled around in water for 30 minutes with no problems. When got the nerve to try full throttle. It powered up to full throttle fine and ran ok for about 30 seconds before starting the same old bogging down and running like it dropped a couple of cylinders. Would run like that for a couple of seconds before dying. Reprime it and get another 20 to 30 seconds of rough idle to get me back to dock. If i let it sit for a while it will crank and run forever again at low throttle.

In light of the above, i did a couple of things. First hooked up a small tank of fresh gas and gave it a try. Same outcome as above. Also installed a water separator on the regular tank, which needed to be done anyways, same outcome.

One new thing i noticed is that the volt guage normally reads a little over 12v with the engine running but when the engine starts to drop out the gauge goes up to around 14v and then bounced between 12 and 14v a couple of times before it died out. Not sure if this has any relevance, but i pass it along.

I can hear the high pressure pump activate when the key is turned when first cranking but havent been to confirm if its still pumping when the problems start. Any good way to test the hp pump? Marion mentioned maybe the hp pump was cutting out, which makes sense to me.

What are the symptoms a bad injector? Would it cause problems at all rpm ranges?

Also, new resistor plugs just to be sure too.

Looking for any help i can get. Thanks everyone.

Curt
 
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rodbolt

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Re: DT140 - not running - trashed fuel pump?? (Update - Pump ok...still no go)

all that junk went into the VST and the high pressure filter,change the high pressure filter and clean the VST and pump inlet screen.
looks like a lean mix caused flames in the crankcase that melted the check valves.
fix the fuel system or buy a piston.
low rail pressure from a clogged filter,deective lift pump or a restriction can cause a lean runnig engine.
each injector also has a filter that if clogged can cause a lean burn.
check fuel rail pressure at the problem RPM,if its ok send the injectors out for service.
 
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jct2005

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Re: DT140 - not running - trashed fuel pump?? (Update - Pump ok...still no go)

Thanks for the reply. I'm checking the pressure at the rail today and will report back with the findings.

Vst was clean. Cleaned the vst screen and low pressure filter (neither had significant issues).

I've ordered a service manual from brown's to help with stupid questions. Until then I've been going over the brown's parts diagrams like crazy and I'm not finding the "high pressure filter." Sorry for the dumb question but can anyone point me in the direction?

Thanks.
 
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jct2005

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Re: DT140 - not running - trashed fuel pump?? (Update - Pump ok...still no go)

Ok, checked the pressure at the rail. Right at 35psi the whole time, even after the engine started dropping out. So per Rodbolt's advice, will now pull the injectors and send them out for service.

In case the injectors dont fix the problem, anything else it could be while i wait? Thanks.

Still not seeing a high pressure filter...

Thanks.
 
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rodbolt

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Re: DT140 - not running - trashed fuel pump?? (Update - Pump ok...still no go)

if that filter clogged you simply could not maintain rail pressure.
all the vapor seperator does is insure the high pressure pump has a clean VAPOR free supply of fuel. its also the place where return fuel from the rail goes.
gasoline under a vacum has a very low boiling point,its why cars now mostly have the pump in the tank.
thats why fuel rail pressure testing at the problem RPM and load is imperative when troubleshooting modern machines.
 
J

jct2005

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Re: DT140 - not running - trashed fuel pump?? (Update - Pump ok...still no go)

Rail pressure good from gauge check. All screens double checked when pulling the injectors. All screens clean. Also, also injector screens clean too (well on the outside for what that's worth). Injectors pulled and being shiped out for service in the am.

Also, as an aside, new battery too and cleaned all connections, which needed to be done. Seemed to run a little better on the last test run but I'm sure my imagination is willing it to be.

Will update everyone when the injectors are back and tried out in the boat. If suggestions for any other items to check in the interim I'm al ears.

Thanks for everyone's help!!

Curt
 
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jct2005

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Re: DT140 - not running - trashed fuel pump?? (Update - Pump ok...still no go)

Update:

Injectors back from being serviced. Reinstalled and test run. Same basic result. Cranks and idles around perfect. Throttles up to full power for 30 seconds or so then acts like it dropping a cylinder or something and then went go over 1800rpm.

Any suggestions? Out of ideas. Thanks.
 
R

rodbolt

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Re: DT140 - not running - trashed fuel pump?? (Update - Pump ok...still no go)

have you tested the alarm system?
its possible the ECU is tripping the RPM reduction and your not hearing it.
but its still possible to test pulser coil outputs,stator coil outputs and injector firing voltages to rule out electrical.
my bet is still on the fuel.
but at this point I would restart with the basics.
 
J

jct2005

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Re: DT140 - not running - trashed fuel pump?? (Update - Pump ok...still no go)

Thanks for the reply.

No, I have not tested the alarm system. Other than the buzzer sounding at engine start, I haven't received any other feedback from the alarm.

I have the service manual and will check the electricals as you suggest.

Are there any other things regarding the fuel system I should check?

Thanks
Curt
 
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