Hesitates after start (600RPMish) for 3 seconds - then runs normally

[onetonjohn]

Starts right up after waiting for glow plugs. Only thing it runs really slow for 3-5 seconds (maybe 600RPM ), then runs normally. Anyone had this happen? Curious what would cause this?

 

[Nero]

Any exhaust smoke? Might be fuel bleed back

 

[onetonjohn]

Didn't look. I know the return lines are leakproof. Fires right up after sitting for weeks.

 

[IDIBRONCO]

This may not have anything to do with it, but is your fast idle working?

 

[onetonjohn]

I think so, but I don't normally push pedal to the floor to set it. Should I be doing that before I start it?

 

[ihc1470]

Yes

 

[IDIBRONCO]

I say to try it and see what happens.

 

[onetonjohn]

I'll try it this weekend. Hopefully I'll get some time with my trucks.

 

[onetonjohn]

Got a chance to try it. Push to floor and start. Brown truck fires right up at high Idle. White one (the one I'm working the bugs out of) fires up, but slow after a few seconds, it comes up to normal RPM - seamed slower today to get up to normal idle. Noticed a fair amount (maybe a lot) of white(ish) smoke cause I parked next to a building and there was no where it to disopate.

 

[Clb]

Sounds like Air intrusion, from fuel drainage .

 

[onetonjohn]

Before injection pump - draining fuel from the filter? The return line system is tight. I can check the filter is still full before I fire it up.

 

[IDIBRONCO]

Unless it does the start, run, die, lots of cranking thing or runs roughly for a bit after you first start it, I doubt that it's air.

 

[onetonjohn]

That's what was happening before I fixed all leaks in the return system. Very annoying and kinda PITA to get all the leaks (took several rounds for me).

 

[onetonjohn]

The white smoke... Retarded timing? I haven't timed it yet. Could that affect initial RPM? RPM issue from low fuel pressure from weak lift pump (Till RPMs ramp up)??

 

[Clb]

Idi bronco has a point....
Been a minute since I looked, isn't there a return or feed check ball for the i.p. ( seems there’s acheck on the ip? Yes?)(return to tank in the filter head has 1.)

If its leaking then the ip is starved...
Fwiw
I had the schrader core unscrew inside the plastick cap once....
What controls the fuel shutoff valve in the i.p.? Think Of The Possibility of a short, or low voltage situation.