On the first start of the day, it will crank and after it starts and I let go of the key, it stumbles once or twice, like it's not getting any fuel but then immediately smooths out and runs like a champ the whole day. Yesterday I didn't start it until 4:00 in the afternoon, and it stumbled three times.

I have the hutch mod and pre-filter. Does anyone know what might cause this, if it's a problem, and how to fix it if it is?

 

What are the outside air temps when she stumbles?

Also, check battery voltage when the glow plugs are on and off.

 

It was about 80 yesterday when I started it. Most times the temps are between 50 and 70. Never any colder.

Voltage is about 14.5 with the plugs off and 11.something when they're on.

 

Those voltages all look very good and at those temps you don't need to worry about the glow plugs.

How many miles on the starter?

 

I have no idea, it's probably original. It cranks and starts fine and it stumbles within a second of the starter disengaging.

 

Here is what you need to start:

- at least 10.5-10.7V when the glow plugs are on. You have this

- at least 100 rpm's. Do you have a scanner or AE to check this?

- ICP of 500 psi. If you unplug the ICP sensor the PCM will not get the reading from the sensor and default to 750 psi and set a check engine light. If you don't have a scanner - unplug the ICP sensor and see if it starts different.

- PCM/IDM sync signal - this shows as 0.6ms FIPW(fuel inj pulse width). Once the other minimums are met, the FIPW will jump above 3.0 ms.

 

I don't have a scanner. I should point out that when it's warm, it starts and idles perfectly.

When I go to start it later today, I'll unplug the ICP. Also, the ICP is only a couple of months old.

 

When the engine is warm or the air temps are warm?

 

When the engine is warm. The air temps are always warm here I live.

I've noticed that if I cycle the glow plugs two or three times (and therefore the fuel pump) I don't have the problem. I am beginning to think some air is getting into the fuel system and when it sits overnight, the bubbles collect somewhere and cause the stumble when they get to the injectors.

 

Possible, but it's quicker and less messy to remove the starter and see if it sounds like a baby's rattle when u shake it.

 

I unplugged the ICP today, and this is what happened:


This is the same behavior that it does when it starts cold, but it goes away after one or two surges and then smooths out. I plugged it back in right after this and it started and drove normally.

Also, how long before the SES light goes out?

 

Mine used to Romp-romp, then settle down when cold outside.

I changed from 15w-40w Rotella to Delo 5w-30w and it was cured immediately.

Of course, it may have been FRESH CLEAN oil, too

How many miles are on your oil?

 

I forgot to write down the mileage last time, but probably about 3-4000. I'm pretty sure it's 15w40. I will switch to 5w40 next oil change and see if that cures it.

 

The video clip sure explains it better than I imagined earlier,

Possibly a sticky IPR? You said the behavior went away after plugging the ICP sensor back in?

 

Yeah but why? Because I started it again? Or because I plugged the ICP sensor back in?