1HZ Stuttering Issue (1 Viewer)

[370HSSV]

Hello, so I just got a hzj105, starts right up without any smoke. In constant throttle, it stutters / breaking up like 2800 rpm, sounds like 2 step somehow, blow some white-ish smoke out of exhaust. No blow by out of oil cap. It was fine in California, but here in Colorado (maybe elevation?), this problem started to show, just put in new air and fuel filters and fresh diesel. Glow plugs all have continuity, anywhere else to check? Somehow fuel related maybe?

New to 1hz, any advice would be great on what to check.

 

[Gimme a 60]

Sounds like air in fuel lines.


I had a diesel leak that caused my rig to stutter at 2500 RPM, it idles and ran great until I hit the road then it would bog down.


That is probably what happened, considering you replaced the lines.

 

[370HSSV]

Sounds like air in fuel lines.


I had a diesel leak that caused my rig to stutter at 2500 RPM, it idles and ran great until I hit the road then it would bog down.


That is probably what happened, considering you replaced the lines.

I didn't replace any fuel lines just the filter then primed it, started right up again. Any idea on how to properly check where could air getting into fuel lines? I was switching between main and sub tanks trying to listen to that solenoid couple times making sure both tanks work before I fueled up, when i popped the fuel cap open, definitely some more than what it used to be for pressure in the tank somehow. blew the cap off a bit. Does that indicates anything?

 

[sodafeld1]

From here sounds like a fuel thing, either a leak and air getting in the line, or maybe bad fuel, which seems to happen often here on mud. How much extra elevation? don't think that would be it.

I rarely take my 2h over 2400 rpm usually around sit around 2-2100. The old diesels don't like high revs I believe.

If a clean machine, any fuel wetness can be observed on the fuel hose , lines , around the injector pump, injector ports.

 

[Squash]

Install a clear hose from the IP(injection pump) to the fuel filter. Any air will show up as bubbles. Bubbles will tell you that air is being sucked in up stream. Tighten things up and or repair the system until the clear line no longer has air bubbles.
If need be strap a gopro or camera and video the clear hose section under load conditions.
You can run with the clear hose for months...just keep the stock hose handy in your unit. Suspecting that when you changed the filter is your problem.

 

[mudgudgeon]

Agreed with all the above. Fuel filter and primer pump assembly is a common failure/ leak.
Search in here, this is a common problem with simple solutions, lots of threads about this

 

[370HSSV]

I am a mile or 1.6km over sea level. Engine bay seems like it does not have any fuel wetness, I have not checked under the vehicle for the lines go from tank to engine bay.

Sounds good, I will double check around using the clear hose for bubbles.

This happened before I changed out all those filters, that is the reason why I changed them out, it's still doing this stuttering thing. But there is probably some other places air can get into the line somewhere.

 

[mudgudgeon]

The fuel system is under suction, from the tank to the Injection pump.
It can suck in air through a cracked or loose hose, or filter oring without any visible leak or wetness

 

[sodafeld1]

The fuel system is under suction, from the tank to the Injection pump.
It can suck in air through a cracked or loose hose, or filter oring without any visible leak or wetness

yeah true, This is the fine art of diesel systems, must be 100% sealed. Somehow I am thinking around the ip can be very hard spots to find leaks, lift pump..