Hi all.

Thought I might post here after months of no success.

My 1995 Hilux Surf (1KZTE) is blowing constant black smoke (misfire?) and using heaps of fuel (about 250-300km to a tank). When the misfire occurs under load it just splutters.

https://www.youtube.com/watch?v=6p5c...ature=youtu.be

Some days (like today) I can jump in and drive 100k's without a single issue. I just don't understand!

I have taken it to three shops here in Perth, Western Australia who haven't been able to diagnose the problem. I know it's very difficult to provide assistance over the internet, however is there anything people would recommend I try? I've done just about everything and nothing has worked.

Thanks.

Check compression, check for codes, check for sticky valves as that popping noise sounds just like a sticky valve, if those are OK then it's probably a problem with the injector pump.

Compression fine, only error was 24 which is the air intake sensor. Changed that and it went away, however it seems unrelated as it didn't fix anything. The diesel place I took it to said there's no reason why it would be the fuel pump and confirmed that it was fully functional. Injectors have also been changed. I've also got another ECU here that I'm plugging in tomorrow morning.

Don't think we've looked at the possibility of a sticky valve yet... any suggestion as to the best way to diagnose something like this?

Thanks.

Since you seem to have ruled out fuel and compression what is left ??

Something restricting the amount of air being drawn into the engine.

I am sure the air filter has been replaced .

Rodent nest in the intake .

Something collapsed at times restricting air.

As you say sometimes it works like it should.

Very hard to find a intermittent problem.

Other then a computer problem increasing the pulse time to the injectors dumping far to much fuel for the amount of air.

The fuel pump and injector pump are two different things. The fuel pump delivers fuel from the tank to the injector pump, the injector pump delivers fuel to the cylinders. They have very close tolerance parts and takes specialized people and equipment to rebuild them. You need to find a shop that specializes in diesel engine repair, they'll narrow it down quickly. A sticky valve can be diagnosed with a vacuum gauge hooked up to intake manifold vacuum. If the vacuum jumps wildly at idle, that's a sign of a valve sticking.

Yep, all filters etc replaced. I'll try this new ECU today to see if that does anything.

Thanks! I'll give it a try.

Remember that will only work if this model diesel has a throttle plate. No throttle plate, no vacuum for a vacuum gauge to work.

Yeah. I just thought of that.

Don't think it does, I'll have to check.

It does. I'm sure it has a throttle valve, I looked it up before posting that as I know some diesels don't have one. If you can't find a spot to plug in a vacuum gauge, listen to the air intake at the air filter. If you hear loud popping noises from the intake that's valves sticking. It's really loud popping, so don't mistake all the other noises for that.

Just checked the error codes once more, still getting error 24 (air intake temp sensor).

I'll do the sticky valve check soon.

If it's a intermediate problem, it seems like it would be something electrical and not a mechanical problem. Couldn't hurt to check though

Yeah, track down the code first. Is the turbo working OK?

Hey,
That looks like a clogged silencer too...The spurts of smoke come from pressure building. .kenya style we remove the silencer and cut open the top scrape and pour the soot then pressure wash. Bang back the top and gas weld it. Works wonders on performance and consumption.
some silencers built without blow by.
running the engine after reinstall will dry out the silencer.

Soot pic before pressure wash