Kzj78 rough idle / misfire/ no power when cold outside (1 Viewer)

[MartyG]

I have an issue with rough idling/misfire and no power under throttle when it’s “cold” outside.

vehicle:
Kzj78 with 1Kzte engine
155,000 kms
No modifications other than k&n air filter

conditions:
-Cold start
-Temperature outside when problems occurs is 55 degrees Fahrenheit and below.

problems:
-Misfiring
-Rough idle
-No power under throttle until completely warmed up to operating temperature.

When going to start the car I let the glow plugs warm but still takes a little longer to start. Once it starts it seems ok but has some misfire and a bit of rough idle. I use the button for the higher idle as I let it warm up.
I originally thought it was glow plugs but having no power under throttle is weird to me. The engine doesn’t rev unless I SLOWLY ease into it and even then it sometimes drops in rpms and wants to die.
I haven’t changed or checked anything as I’m looking for advice first.

 

[coldtaco]

I know the old 2H had a "smart glow" (not proper word, can't remember) that would run almost full voltage to the flow plugs for a few seconds then reduce the voltage to half for the rest of the timed glow cycle. I don't know if yours has something similar. If it does and it is faulty that might give you what you are describing. Does it smoke much when this happens?

 

[MartyG]

I know the old 2H had a "smart glow" (not proper word, can't remember) that would run almost full voltage to the flow plugs for a few seconds then reduce the voltage to half for the rest of the timed glow cycle. I don't know if yours has something similar. If it does and it is faulty that might give you what you are describing. Does it smoke much when this happens?

I can see that. Unfortunately I don’t know if it does have that feature either. And no it doesn’t smoke.

 

[Waikato Willy]

I would be checking for air in the diesel lines and check the primer is nice and hard to pump
sounds like you bad air locks and stuffed glow plugs

 

[Squash]

Suspect she's sucking a bit of air, check all the fuel supply lines and fittings. Another trick is to bypass the filter with a clear hose from before the filter directly to the injection pump.
Doesn't seem cold enough for fuel gelling or ice, but you can try a fuel conditioner.
If she settles down after warming up relax!
Diesel engines have their own character's, as long as they start and smooth out once warmed up.
Don't get all OCD.