fires then dies, cant figure it out

bdp

bdp

beans diesel performance
Joined
Apr 23, 2006
Messages
1,730
Someone brought me a cobbled up mess of a 4b in a late model Land Cruiser and said finish it. All they had done was motor sitting in it and tanny in it. Trying to get it started and all it will do is fire then quit, if I keep on the starter it will get rollin real fast and will keep running but at areally really low rpm and rough as heck. If I attempt to give it any throttle at all it will die instantly.

Should have plenty of lift fuel, has mech pump still on it and I also hooked up the in tank electric pump to feed it.

I pulled the shut off valave and it looks good and works fine out of the pump so I think thats fine.

I have pulled and cleaned all the injs, I think they are fine.

I am to the point of suspecting the pump to be bad but I am not sure, hoping to get some guidance of what to do next.
 
bdp said:
Someone brought me a cobbled up mess of a 4b in a late model Land Cruiser and said finish it. All they had done was motor sitting in it and tanny in it. Trying to get it started and all it will do is fire then quit, if I keep on the starter it will get rollin real fast and will keep running but at areally really low rpm and rough as heck. If I attempt to give it any throttle at all it will die instantly.

Should have plenty of lift fuel, has mech pump still on it and I also hooked up the in tank electric pump to feed it.

I pulled the shut off valave and it looks good and works fine out of the pump so I think thats fine.

I have pulled and cleaned all the injs, I think they are fine.

I am to the point of suspecting the pump to be bad but I am not sure, hoping to get some guidance of what to do next.
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If it has the rotary pump and the injectors are too big, you need to drop down to the 2 to 1 pump drive gear. With that gear it drives the injection pump twice as fast allowing the first pulse to build a little pressure in the line and then the second pulse makes enough pressure to pop the injector.
 
Thats the problem I guess, I know nothing about what is on this motor. To me it looks like an all stock ve 4bt industrial motor, or like out of a bread truck or something. Looks like it had been sitting outside for a while. When it first hits it will throw a nice smoke puff like its getting good fuel but then smoke goes away and it stops hitting. Kind like it throws a nice punch of fuel as soon as you hit the starter but then it stops putting out fuel.
 
Sounds like head and rotor wear in the pump. You can remove an injector and then connect it back up to the injector line. Try turning the engine over. If it is getting enough fuel from the pump it'll fog up the shop, if not you'll know it.

You could also try putting that solenoid in minus the spring and plunger. Just be forewarned, if it starts you'll need an alternative method for shut down. :)
 
Ya I thought about that and the shut off, just could not think of a good shut down method LOL.

Will try that with an inj and see what I get.
 
There's no reason to assume it's something inside the IP unless you just like to self-confirm Murphy.

I would rig a connection that would let me gravity feed fuel into the IP inlet fitting. I would then take the plunger out of the shut off solenoid. Then I would disconnect the injection lines and crank and make sure fuel is coming out strong.

If fuel is coming out strong, the pump could be timed wrong or you have something wrong inside. If fuel isn't coming out strong, then you have something wrong inside.

If it's something broken inside of the pump, it sounds most like a broken return spring or something bent or broken on the governor arm. With the injection lines off, a head and rotor would never be worn to the point that it wouldn't push fuel out the lines at 0 PSI; they'll only start to lose volume when asked to produce several thousand PSI.
 
Maybe they turned the pump down for some odd reason. If the fuel screw is not in enough they will do that. I have also had a VE pump do that, after it had been setting for years, once i got some good fuel through it, it was fine. Try the gravity feed also could have an air leak in the supply coming from the tank.
 
The fuel screw didnt look like it had been messed with but does look like it is way out, I will try and screw it in and see what happens.

If I loosen the liines up it will squirt fuel 3-4' so it seems like it is getting good pressure I am just not sure that it is holding that pressure past the first initial crank.
 
Turned fuel screw way in and it will fire right up and idle pretty good now but if I so much as breath on the throttle it will die instantly. It will fire right back up and idle so dont think its air in the lines.

Pump?
 
Smokem said:
Sounds like the throttle shaft is not indexed properly.
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That or its just had better days! If you cranked it, it usually runs away if you took off the tamper collar if it has one. If i think of anything else to try will post it up.
 
Are you talkin about the collar on the screw? I took it off and turne dthe screw way in, that made it atleast idle.
 
It does sound like a throttle indexing problem, or something bent inside the IP.

With the fuel screw all the way in, you're begging for a runaway that won't be stopped with the shut-off lever on the side of the pump once you get the governor problem figured out.
 
bdp said:
Turned fuel screw way in and it will fire right up and idle pretty good now but if I so much as breath on the throttle it will die instantly. It will fire right back up and idle so dont think its air in the lines.

Pump?
Click to expand...

Broken or missing spring inside the pump will cause this also.
 
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