1998 DT115

Bhack18

Recruit
Joined
Aug 30, 2021
Messages
3
Hey all, requesting a little help with a motor that is frustrating me. Recently it has been intermittently having issues starting. More so when it is cold. Normally you turn the key and it cycles the fuel pump 5-10 seconds then the buzzer sounds for a second or so. Then she starts right up. Now the issue is when you turn the key the fuel pump never stops cycling and of course the buzzer never sounds. Even if you turn the key all the way to start while it’s cycles it will not start. I did a rebuild on the fuel pump in case it was losing pressure but that didn’t help. The squeeze hand pump remains firm. The fuel filter was cleaned. The fuel/water separator was replaced. I hand pumped fuel all the way through system after all those things were done but still didn’t work. Is this a mechanical issue or is this electrical issue? Relay or something? I appreciate any thoughts or ideas.
 

99yam40

Fleet Admiral
Joined
Sep 7, 2008
Messages
9,097
motor needs good compression, good spark at the correct time and the proper fuel to air ratio to fire the cylinders.
what are you missing?
 

Bhack18

Recruit
Joined
Aug 30, 2021
Messages
3
Right now it doesn’t make it to that point in order to start. It doesn’t make it past the initial fuel pump cycling process.
 

99yam40

Fleet Admiral
Joined
Sep 7, 2008
Messages
9,097
you need to know if the compression is good on all cylinders, is it?
you need to know if all spark plugs are getting good spark while spinning the motor over to start, and are they hitting at the correct time?

If and only if these things are good, then you are left with a fuel problem.


no reason to chase a fuel problem if there is a problem with something else

monitoring fuel pressure will tell you if the pumps are doing their job
 

Bhack18

Recruit
Joined
Aug 30, 2021
Messages
3
99yam thanks. I will check compression. Spark is good. It was checked previously. I will attach a video later today to in order to show what’s going on.
 
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