need help im desperate!

[buler]

i have a 1999 DT140 EFI. compression is 95 on all cyl. fuel is good, injectors have been tested for flow and leak. spark is good on all 4 and i have tested windings on pulser coils and charge coil and hi and low coil. problem is the motor is running very rich. i pulled the throttle body and there was a puddle of oil in the intake manifold. not sure if the gas evaperated or what. motor is just bogging down and wont start unless you open it up all the way after you run it a while, fuel is not getting in from vst or fuel reg. oh and i checked the low pressure fuel pump and it holds pressure. no leaks o rings look good. could the throttle linkage be messed up?(never touched it) or could one of the sensors be causing it to run so rich? i am frustrated and stumped. any help anyone can give or insite would be greatly appriciated. the nearest dealer is just a short 7 hrs away. the boat mechanics ive talked to wont touch this motor. thanks

 

[99yam40]

Re: need help im desperate!

fuel is not getting in from vst or fuel reg.

not sure what you mean by this statement

Looks like the motor will start and run well, but has a hard time starting after running and warmed up. Or is it a different problem
So you have OK compression and spark.

And injectors are good as far as you an tell.

Have you checked the rail pressure to make sure it is not too high?
That could cause a rich condition.

How about timing? have you check that?

I am sure some of the sensors could be a problem, but do you have the service manual and test equipment it calls for in testing this motor and sensors?

 

[buler]

Re: need help im desperate!

I have purchased the seloc book but I don't have the wiring harness kits that are needed to test all sensors. If the pressure was to high on the rail wouldn't the pressure reg. Blow fuel from the relief valve?

 

[buler]

Re: need help im desperate!

The vst and the pressure regulator have hoses that in case of a malfunction would dump fuel into the throttle body. That is what was implied by the statement I made.

 

[buler]

Re: need help im desperate!

As far as I can tell the timing is controlled by the info that the sensors send to the processor. Atmospheric pressure, temp,throttle body angle etc. But if the throttle linkage was adjusted wring I think it would be possible to pump more oil in the fuel that it could burn. Just don't know and don't know how to check it.

 

[99yam40]

Re: need help im desperate!

read manual and test what you can with what you have , at least that is a starting point.
Manual has info on oil linkage and I am fairly sure that is not adjusted by computer
And if you find the timing off from spec then worry about why