Suzuki DT 140 injector problem

[jnr1234]

1999 DT 140. Never had a fuel related problem whatsoever. After sitting for a month I now have fuel spilling out of the injectors when I pump the primer bulb. Motor has fire but will not start. Appears to be a fuel delivery problem. This is consistant with the neddle and seat sticking open on a carb outboard but since this is an EFI I am stumped as to what is wrong. Any suggestions?


Thanks in advance.

 

[99yam40]

Re: Suzuki DT 140 injector problem

Injectors would be my guess, pull and send to be tested and cleaned

 

[jnr1234]

Re: Suzuki DT 140 injector problem

It looks like the fuel is coming out of the VST. Same symptom as if the needle and seat is stuck open on a outboard carb and fuel is constantly spilling out of the top. Looks like the same scenario. Is the VST a servicable unit?

 

[mphelle8vld]

Re: Suzuki DT 140 injector problem

Go ahead and open up the VST, it has the same float setup as a carb. The needle may be stuck or just not seating.

 

[jnr1234]

Re: Suzuki DT 140 injector problem

I think I have it narrowed down to the high pressure fuel pump. When I turn the key I can feel the pump vibrate a little bit but should you not hear it as well? I believe I remember hearing it. Opinions welcome.

 

[99yam40]

Re: Suzuki DT 140 injector problem

a bad HP pump would not cause fuel to come out of VST

 

[jnr1234]

Re: Suzuki DT 140 injector problem

It is coming out of the opening in the throttle body. I have disassembled the VST and did not find any trash in the needle and seat. I found a little bit of junk in the filter screen going to the HP pump. I put everything back together and the problem remained. I am going to taky the VST back apart and soak in carb cleaner. I am then going to pressure test the pump itself. I will post the results. Between the VST and the HP pump I think I can nail it down.

The intruguing thing is I have a twin engine setup and both engines did this at the exact same time.

 

[jnr1234]

Re: Suzuki DT 140 injector problem

Took VST and high pressure pump off. Bench tested HP pump and nothing. Doesn't pump or do anything but throw a spark and heat the wire up. What is supposed to happen when you bench test the HP pump to a battery? Seems like it should...........pump. Am I overlooking something here? BTW long time IBOATS forum member but I had to change my username and password to log on.

Thanks for your replies.

 

[99yam40]

Re: Suzuki DT 140 injector problem

pressure regulator might have a problem, but I have no idea if that would dump to throttle body

I would think putting 12 volts on Pump would make it go

 

[lakensea]

Re: Suzuki DT 140 injector problem

I highly suggest you get yourself a FACTORY manual for that engine. It looks like you are about to start throwing very expensive parts at it without properly diagnosing the problem.

Cost of a high pressure fuel pump - $576.35
Cost of a VST assembly - $355.36
Cost of a fuel pressure regulator - $186.16

Cost of manual - priceless at $56.79

 

[jnr1234]

Re: Suzuki DT 140 injector problem

I have a manual and I have removed the HP pump and bench tested it. My question is this? When benching testing this at 12V should you not hear the pump running or feel it vibrating? It does nothing when hooked to 12V. I have 12V going to the pump at the engine as well. It is just odd that both of my motors would do this at the same time.

To clarify I am using treated ethanol fuel. This happened at the same time both batteries went bad on me.

 

[jnr1234]

Re: Suzuki DT 140 injector problem

Ok. Problem solved. Keep in mind this happened over sitting a couple of weeks and to both motors at the same time.

Had the fuel pump off of the starboard motor for bench testing. As I stated earlier in the week it would do nothing when I ran 12 volts to it on the bench. Tapped on it lightly and then hooked it back up. It shot out the most disgusting blob you have ever seen. Problem solved. Went out to the port motor and tapped lightly on the HP pump and turned the key. I could now hear the pump operating and the motor fired right up.

It is very odd that it would happen to both motors at once but I guess this is the problem with ethanol. Now to siphon out all of the old gas and start over. I thought I would post the results because sometimes it is the simplest thing that fixes problems. Thanks to all for your input.

James

 

[99yam40]

Re: Suzuki DT 140 injector problem

If the other pump pushed out a blob like you said the 1st pump did where did it go? to the injectors?
probably need to clean everything after draining and flushing tank and lines.
Many filters and screens in those motors that will plug up