1989 LJ70 - black smoke and loss of power - help needed

[m4ttz4]

Hello community,

I recently got my hands on a LJ70 2L (no Turbo). The body is in great condition but I have issues with the engine.

The truck runs fine on lower rpm but as soon as there is an incline, it blows black smoke and does not really have much power to it, to a point where I have to climb hills on the highway in 2nd gear at around 30 to 40 km/h. It blows out a ton of black and there is no power. It works decent on flat land but when I put the pedal down all the way, it still blows a ton of smoke. This happens on the highway in 2H and also offroad in 4h, 4l is way better. Fuel and air filter are new.

As I said, it just does not have much power and struggles a lot with longer inclines to a point where it starts to overheat. I know the 2L is not the strongest engine but it should not be that bad I dont think. I dont have oil in the water so I don't think the gasket is bad.

Does anyone have any idea what could cause such an issue?

Any help is appreciated,

Thanks in advance
Matt

 

[Franglais]

LJ70, I`ve no knowledge of but as a general case:
White "smoke" is water vapour, (or diesel vapour when starting up from cold) blue smoke is burnt oil, black smoke is unburnt excess diesel.
If air filter is clear, then possibly bad injectors, worn pump, injection timing out?

 

[Tel Boy]

Same as above.

If the air filter is new then make sure there are no obstructions in the air pipes all the way from intake to manifold. It sounds like not enough air or too much fuel or the timing is way out. My old LJ70 used to make lots of smoke when towing uphill but it was never short of power (!) when smoking and never overheated. It turned out to be very worn injectors - too much fuel. New injectors made a clean exhaust and better fuel consumption, but less power.

 

[Shayne]

"I recently got my hands on a LJ70 2L"

To turn up the fuel is a well recognized way to increase power because factory settings are usually a little lean in order to improve mpg and emissions , but only if it also gets enough air allowing the fuel to burn .

I believe your pump is adjustable so maybe its been messed with if your air filter is new .

 

[outdoordan]

First step remove air filter.

See if that makes any difference

After that its timing.