1990 HZJ-77 Stalling Issues (1 Viewer)

[climberoleg]

Hello All,

I have been working on restoring a 1990 HZJ-77 while stationed in Japan. We bought it last year with 160k miles. It had a bunch of hidden rust and other hidden issues that I have remedied over the last year and up until recently it had been running beautifully. Like many of these trucks purchased in Japan this one did not have a service history unfortunately.

When we bought it we had all the fluids base lined at a reliable shop in Okinawa. The last thing I did to the motor was add a K/N filter, change the oil to full synth (cant remember the grade) and recently had the fuel filter changed out as well.

Over the past month the truck started to have issues stalling out when its not fully warmed up. I have to use the choke for at least 15 minutes to prevent the motor from stalling out when its idling. Once the engine is fully warmed up the issue resolves if the temp outside is greater than 65 degrees. The temperature dropped down to the 50s today and even when the engine is warmed up it wants to stall out unless the choke is turned up.

When this is all happening and I am driving the car frequently has no power and pressing on the gas does not rev the RPMs up until the block has warmed up all the way.

I plan to take it in to the shop in the next week to further look into this but I am hoping the pros here have some suggestions for me.

The diesel pump was recently checked and has no leaks. I have no idea how good/functional the injectors are.

Here's a picture of it for fun!

Thanks in advance for any help and suggestions,

Oleg

 

[coldtaco]

If it had the original engine then it doesn’t have a choke. It has a manual idle up function/knob. If it’s an auto that probably could add more things to check. Has the filter on the fuel pickup been cleaned/changed?

 

[Rigster]

Hi Oleg! Nice 77, it looks great!

The HZJ motor from factory that should be the one in this machine, and all diesels only need 2 things to run (provided compression is in spec): fuel and air.

I suspect from the description of the symptoms this is a fuel starvation issue. I would suspect since one of the things that were recently done when you started to have problems was a fuel filter, try changing the fuel filter again. Make sure you use a respected brand name or just go OEM. It is possible you got a bad filter.

Alternatively, when it was changed, something was not done right, something was disturbed, and now you have air getting into the fuel system.

 

[Squash]

Use a clear hose from filter outlet to the IP inlet. If there are lots of bubbles she is sucking air.
Your task is to check every connection towards the fuel tank.
Most likely culprit is at the filter/primer.
Diesels suck fuel as in vaccum and therefore you rarely ever see a fuel leak.

 

[roscoFJ73]

The original filter is the best, a K&N is step backwards IMO. I dont know why people think K&N are the best?

But back to your problem, what is it idling at without the fast idle knob turned?

 

[climberoleg]

Hi guys thanks for the responses. I am taking it to a diesel specialist tomorrow, but it looks like the diesel pump has started to poop out.

It idles at 700 generally. I turned it up when the issue first started to occur but I think as the pump was going bad the issue only worsened as I drove it more and the weather got colder.

I'll send an update once they have a look.

 

[climberoleg]

The original filter is the best, a K&N is step backwards IMO. I dont know why people think K&N are the best?

But back to your problem, what is it idling at without the fast idle knob turned?

KN is the air filter not the fuel or oil filter. IMO they're easy to clean so I like creating less trash I guess.

 

[roscoFJ73]

KN is the air filter not the fuel or oil filter. IMO they're easy to clean so I like creating less trash I guess.

KN do not filter as well. I was talking about the air filter. One or 2 paper airfilter ever year will not kill the planet and the paper and metal materials are both recyclable.

 

[climberoleg]

KN do not filter as well. I was talking about the air filter. One or 2 paper airfilter ever year will not kill the planet and the paper and metal materials are both recyclable.

Touche! I guess I fell victim to the media hype. You're right there is a quite a body of literature on this and it totally makes sense. Letting in more air means letting in more dirt. Same as a face mask lol. So relevant to our current lives.

 

[roscoFJ73]

Touche! I guess I fell victim to the media hype. You're right there is a quite a body of literature on this and it totally makes sense. Letting in more air means letting in more dirt. Same as a face mask lol. So relevant to our current lives.

KN are a performance filter originally for dirt bikes. These are engines that were never expected to go half a million klms. Ive checked the air intake after multiple paper filter changes and never found any sign of dust entry with the OEM filter set up.
Toyota fo make a a reuseable filter for landcruisers, I dont know about the efficiency of them.