turning up the pump

[genchowford]

Will I be wasting my time by turning up the injector pump because I believe it has worn down to where it no longer is pumping any diesel, or when a pump reaches that point, does it need to be replaced? 92 7.3 idi stanadyne
thanks

 

[Agnem]

Pumps naturally retard and reduce fuel output due to wear, so no.. it's not a waste of time. However, more important would be to get your pump timed. Do that, and you may not feel like you need to turn it up. Touching the fuel screw does require that you have a Pyrometer installed regardless.

 

[Diesel JD]

What do you mean by not pumping any diesel...if it's at that point, the truck won't idle, run or start, that pump is junk, and maybe not even good as a core, depending...

 

[genchowford]

Im just wondering if the ip has worn enough that it's right on the threshold of supplying enough diesel for the truck to start and or run. I thought I had it fixed yesterday, but I had shot a squirt of diesel down the throat to get it started. After it started, it ran just fine. Then again this morning, it wont start, probably without another shot of diesel. So, should I turn up the pump a hair? Or maybe it's a supply issue to the ip. Shouldn't it be about 7 psi?

 

[Diesel JD]

You shot a squirt of dieel down the intake......that wasn't a very good idea. Ever hear of fuel hydrolock? If you must use starting aids...and this is not recommended unless perhaps you have a lot of experience with engines and know not to use too much..... you should use a a quick whiff in the air intake stream preferably as someone else turns the engine over. It will knock and sputter and sound horrible but should smooth out in a few seconds. I've only ever done something like this once or twice. Kinda scared me that I might blow up my engine... bend a rod or something. It is safe if you know what you're doing and most importantly you must completely disable the glow plugs from cycling when you try this otherwise it could cause an explosion. a severe backfire, start the engine backwards...many bad scenarios are realistic.

 

[genchowford]

so if I was to turn up the pump, does that mean turning up the pressure or the volume, or does one follow the other?

 

[Clydesdale]

I am gonna answer Volume.. now lets see if the guru's agree with me.

 

[Agnem]

Correct. Presure will always be the same. Your starting problem is not fuel volume related. If you're cranking it and you are holding the throttle pedal down some, then you are more than compensating for any percived loss of fuel volume at idle. Actually, these pumps are not AT idle when you first start the truck. The govenor actually will advance the throttle slighly on start up, but it immediately throttles back to idle as the RPM's come up. Hence the often present puff of black or blue smoke. Your problem is more likely timing, or your pump is just that worn.

 

[redneckaggie]

you have to give more info here. problem could be glowplug related as these trucks will not start correctly without functioning glowplugs

if the truck runs perfectly fine after startup then i would lean more towards glowplugs or timing

 

[genchowford]

think you're exactly right. must be the glow plugs. checked the resistance, they all were good, but it could be the controller, will check them for heat tomorrow.

 

[93f250idi]

while cranking does it white smoke??

 

[genchowford]

took off the return line and turned on the electric pump and nothing came out! just turned on the ignition though, should I be cranking the engine in order to get the flow or should it be flowing with just the pump turned on? Or is something stopped up in there? Getting about 10# pressure at the schrader valve.
thanks

 

[Agnem]

took off the return line...

Please be specific.

From where did you remove the line, and why did you take it off?

 

[genchowford]

the return line on the top of the ip, nothing coming out cranking or not

 

[icanfixall]

When was the fuel filter changed last.... Did you fill up on fuel from a differant location last time.... Could be lots of differant things causing the hard starts. Hopefully your not pumping fuel from the electric pump thru the mechanical pump on the motor. Thats danderous because when the mechanical pumps diaphram breaks in will flood the oil with diesel. That will ruin the motor fast. Really... We need more information on whats happening. How long is the glow plug "wait to start" lite on. Does the motor run ruff when it starts.... During cranking what color is the exhaust.... When it starts what color is the exhaust...