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Is black smoke due to restrictive exhaust manifold?

5819 Views 48 Replies 7 Participants Last post by  Tickford, 
T
First post on here, and I dont like jumping in just for info. So here is a bit of background.
I was working in Bougainville as a Stock Inspector back in the 70,s when I found this Forward Control Land Rover down the bottom end near Buin.
My wife and I rescued it for a slab of SP beer and towed it back to Kieta on an A frame behind my old diesel wagon.

We got the 6 cyl going and used it for work then when I finished my contract in 1980 we took it to NZ. NZ did not work out so we moved to the Sunshine Coast in Qld
Australia. There I fitted a Perkins 6-247 and used it towing a skidsteer on a semi trailer.
In the 90,s I gave it a refit with a 4BD1 and an LT95 gearbox. I also fitted Salisbury axles front and back with Maxidrive difflocks. and a camper back.

Tried for pics but I cant on first post. So more later.
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T
Woops. Where is the edit button? I meant Salisbury axles fitted as I broke an ENV diff

Found it. The ENV diffs are weak because of the little pinion bearing so I swapped for the Salisbury and increased the track 4 inches at the same time.
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T
Towing back from Buin.

Buin 001 by https://www.flickr.com/photos/[email protected]/
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T
After the Isuzu went in and axle mods.

First Forward Control 001 by https://www.flickr.com/photos/[email protected]
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T
Used it like this , usual trips. Cape York and Simpson until we retired in 2000 and moved to a rural property.
There I built a 6x6 version with a 6.2 Chev but thats another story.

A Couple of FC,s by https://www.flickr.com/photos/[email protected]/
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T
Now to the present. I thought I would do up the old girl again and upgrade to a Turbo. The Holset HX30W.
I cant fit it along side the engine so decided to fit it at the rear and had a manifold made up out of Stainless. Fabbed up the pipework and a Frozen Boost WTA intercooler. with EGT and Boost gauge
It started and ran OK and idled around the yard so I tidied it all up and made ready for a road test.
Last week I got in and started it and revved up to 2000 to see if the boost gauge worked, not a flicker but I read thats normal. But what is not normal is the EGT shooting up to 500 and lots of black smoke from the exhaust.(Still in shed in neutral)
Excess fuel. I checked the inlet piping was free of rags etc and changed the injectors but still the same. The only thing I can think of is the exhaust manifold is too restrictive but readers here know more than I so any ideas?
Keith
Dont know why its in red
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T
Here is a pic.

WtA Intercooler by https://www.flickr.com/photos/[email protected]/
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T
Thanks for your reply Adam. I was thinking perhaps I should have made the manifold with a taper somehow getting bigger as it got to the turbo. I am pleased you think its OK. I was going to unbolt the turbo and see if it still smoked straight out the pipe but I will leave that and try your ideas first. Yes it worked well NA, this has just happened since I put the turbo on.
I have a VDO boost gauge in the intake manifold and its not moving so I will investigate those other options.
I took the hose off the turbo and the thing is spinning.I took the hose off the outlet of the WTA and can feel air coming out but not much, but then I was not revving much either.

Keith
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T
I was reading some stickies. I read about a cold start fuel enrichment thing. Could this be stuck and causing my problem.?
Where is it and what does it look like?
Clutching at straws here.
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T
Dougal said:
What have you done to the injection pump since fitting the turbo? The 4BD1 (non turbo) doesn't have a boost compensator to limit fuel until the turbo spools up, so black smoke before spoolup is tricky to avoid. The A pumps we have run a fuel plate inside the governor which sets fuel based on rpm. This can be modified to reduce fuel at lower rpm to limit smoke but I haven't tried doing that.

I would look for air intake restriction as the source of your high EGT and black smoke while still in the shed.

For your exhaust manifold. The size is fine, the shapes are awkward as the Isuzu ports are rectangular and the pipes are round. A better design if you keep using pipe fittings is to use elbows exiting each port and trim them into the manifold tube so all the pulses are pointed in the exit direction. Sort of like a row of r's. rrrrr

Are you the same Keith from AULRO who once lived in my home town?
Click to expand...
Hi Dougal, I was hoping you would see this. You have a good memory:). Yes it is I.
All I did to the pump when I bolted stuff up was to open the fuel screw one turn. Then when all this happened I screwed it back in again but of course no difference.. I looked for intake restriction by taking that hose off between the intercooler and manifold but it still smoked and got high EGT,s. Perhaps a rat or snake got into the manifold before I got the hoses on. I guess I better pull it all to bits again though I cant smell anything dead.
I cant do much now as my wife fell and broke a couple of ribs so I am hospital visiting every day untill she is out.
Another thing. This inlet manifold has springs under the heads of the fixing bolts. My other one does not. What is that about?
Keith
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T
Came home early today to have another play.
Took off the pipe from inlet manifold to outlet of IC.
Started up and revved to 2500 odd EGT went up to 500C odd and still black smoke. I cant see any obstruction in inlet and its got good suck when holding hand over the pipe.
However, revving up and holding my palm over the IC outlet its easy to block it off and the wastegate rod does not move.
I would have thought 10 pounds or so would be harder to stop and if it was getting 10 pounds would not the wastegate rod start to move. I am still thinking manifold or something wrong with the turbo.
Thoughts?
Keith
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T
Correction. Just had another think. I would not be getting boost anyway as I am still just revving in the shed. So as Adam said its only 2 or 3 pounds so thats probably right.
I guess next step is to pull the exhaust from the turbo and see what happens. I cant see how it would be over fuelling.
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T
This is the photo to go with my previous post.
I might put some number plates on it and do a road test but NYDay is probably not the time. Even in a rural area it would be my luck to get pulled over.
Happy New Year to all.
Keith

turbo install by https://www.flickr.com/p
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T
FOUND IT1111111
Pulled off the dump pipe to see if it smoked without it, looked down and there was the bloody exhaust brake shut.
I had looked at it previously, checked it with the engine going and it moved OK and did not seem to make much difference at a fast idle so ignored it. But here it is shut. I must have put the pipes on the wrong way around. They are both the same colour, black, so too easy. Swapped them around , no smoke and low EGT..
I will blame the onset of oldtimers disease. I was 74 a couple of months ago so that will do
So thats a lesson, a blocked or restricted exhaust can cause those symptoms.
I will take it for a burn up and down the drive next, see how it behaves before a road test.

turbo install.03 by https://www.flickr.com/photos/141809
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T
I think most of the older ones I have seen are vacuum controlled with a diaphram type thing and spring return like a brake booster. Well the one I took off was. This is an aftermarket one made here in australia and is a bit smaller and neater than the old one. I am not all that familiar with other makes of EB,s and later model commercial ones may be like this. I dont know.

Keith
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AdamR. Read through all your thread the other night. Very informative and I will have to read it again.No idea how old this engine is though.I still have to adjust the idle and set the electronic speedo and tacho.
Took it for a run up the drive today and managed 8 pounds of boost in second gear in the LT95.
Next , swap some plates on it and do a road test on the back roads here. No decent hills though.
I originally had a LT95 out of an old Range Rover in it. With this turbo install I pulled it out and put in one of two ex Aussie Army LT95 A ,s I bought at an auction. Pig in a Poke. Had a look inside before I swapped and looked OK but the road test will tell me more. These later LT95,s have a close shift , as in less side to side in neutral which feels different and they have better taper roller bearings in the intermediate shaft. Fingers crossed.With the camper shell on its pretty heavy and the EB is useful on long down hill runs. I have a dash switch that I can turn it off when not needed running around town etc.
The second auto box I put in that 6x6 was a 4L80E behind the Chev 6.2. I had two oil coolers on it and it still boiled the oil. I gave it away and put a 5 speed Isuzu manual box, cable shift behind it. Its good now but the Chev is a bit underpowered.

Keith
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Yeah, I bought it before the internet. If I knew then what I know now I would not have bought it.
The guy here in Brisbane imported them ex Hummers so said they must be good. The other thing that swayed me was I could bolt a Turbo 700 auto up behind it. I had visions that if I got crook out bush my wife could drive me back with the auto. Never happened. The Turbo 700 broke and the 4L80E after it was not suitable hence the Isuzu manual box now. If the 6.2 karks it I can bolt a 4BD1T straight up now. Should have done that in the first place but was ignorant of them. The 6x6 with the Chev has only done 60,000 Kilometers so who knows.
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T
Back again and still working on it. My wife has been crook for the last year or so and I have been sole carer so not much done
FC wiring by https://www.flickr.com/photos/[email protected]/
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T
Getting there, going to take it for another test drive tomorrow.
FC 2a gauges by https://www.flickr.com/photos/[email protected]/
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T
Got to do a test run. Mainly to work out how to get the new VDO speedo calibrated. I was stumped as I could not get the needle to move with one wheel jacked up. It has a Hall Effect sensor on the LT95 transfer box. I messaged the guy I bought it off through ebay and he said "check the pulse"
Did a bit more reading and read the speedo factory pulse. It was 55000.
I looked at the one on the 6x6 I had working and checked it. It was 16000. Trid that on the new one and finally got the needle to move but it read far to fast. Anyway to cut a long story short I rigged up my GPS and using its speedo got my pulse down to 3600 and its nearly right now. Dont know why the big difference to the 6x6 as it has a LT95, 4.7 diffs and 900 x 16 tyres the same as this one.
Now the turbo. Going up a bit of a hill foot flat, starting at 10 psi boost all the way to max at 18 psi it makes a helluva scream. Never come across that before. My Landy with the 200TDI does not do that.
Max boost I can get is 18 at 550 EGT
Dont these turbos get more than that or do I need to open the fuel screw? Nooby on this stuff.
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