Well, you just have to do another trip - camera on, please.
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Hey friends; Just something that I have recently concluded. For my style of gasifier, a cyclone is very important. In a 1 1/2 hour run my cyclone picked up over 1/2 quart of ash dust. Can you imagine throwing that much ash into your 2" cooling tubes. No wonder the cooling tubes need cleaning. TomC
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It is too hot to be in the shop and hotter in the sun— so you get my dissertation.
Subject— truck got where it would not idle.
Conclusion— cleaned the Throttle Position Sensor and problem handled
Discussion— I remember my first trip to Green Bay on wood, I stopped in my mechanics shop to show off. His crew and neighbors all gathered around and we discussed every aspect of this “wonder”. All the time it sat there idling and my mechanic even noted how long and well it had been idling. Fast forward to now and the truck had gotten where it wouldn’t idle on wood or gas. As I said it has been “hotter than the hubs of Hell”, so I haven’t been inspired to take on any “jobs” on the truck. Finally, I have been reading about everyone putting a cable on the accelerator to speed the idle up. Figured that would take mostly bench work and so I “bit the bullet”— I wear blue jeans everywhere-- church, funerals, out to eat, every where except bed ( my wife has something to say about that) so I decided to give up the jeans for my pajama bottoms and a sleeveless T- shirt with my flip-flops. Sitting at the bench was---- O-K, but then I had to go under the dash. Two trips under the dash and I was sweating water, like " a pic gushes blood when stuck". The next day the same situation – a hour or two and working under the dash and I was wiped out. I don’t even remember how many days I spent, but finally got something that "sort of " worked. I was’t real happy with it. All the time in my mind I was reminded that one of our great WK contributors said that this situation was caused by a dirty TPS. I stood back and studied what appeared to be a major project of removing the air cleaner and brackets that appeared to be in the way. Finally, I made up my mind to give it at try and if it got to complicated I would live with my “jerry rigged” cable. Ohwalla!!! It came apart so easy with out all the hassles I had convinced myself would be there. I wire brushed the pintel but it seemed to be to rough for that so I took emery cloth to it and I was able to smooth it up without getting into the metal it’s self. Then I had a small round wire brush that I use to clean tail light bulb sockets. I ran that into the opening and screwed it around a few times and blew air into the opening to clean it out. Put it back to gather and than thank you to who ever recommend this, it is back to working perfectly. Drove it about 30 miles and wow " no more driving with one foot on the accelerator and the other jumping between the clutch and the brake. My smile came back TomC
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Congratulations Tom,
Now you have both belt and suspenders and you can idle around in your pajala bottoms.
Without the WK string, didn’t you have a very variable idle depending on different vacuum (tight or loose charbed)?
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Tom, so just doing a little maintenance now then on the TPS and it will work fine. I think I will do the same on my truck and just use the idle cable when it needs to be cleaned out again. It’s not like in wood gasification there is never any maintenance to do. Lol Thanks.
Bob
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I surely wish you lived across the street so we could sit and talk. You have developed technical knowledge that surpass me. With the Embert design, our char-bed is much smaller than a WK ( ? ) I am not sure how that plays into the situation. I think my char-bed it tight as it has been running well, but last week it did come home on the back of a truck which could have packed or made it fall through to the ash pit (?_)
At any rate right now with the clean TPS, In neutral after a rev-up, the idle drops to 1000 rpm’s and then drifts down to about 700 rpms where it stays.
Truthfully I don’t know my vacuum readings at idle I guess about 5 & 2 inH2O Down the road it is usually 10 & 6. I still don’t understand why on all our designs the ratio comes out to 2 to 1. My cooling rail reading is where the gas flows from the one side of the truck to the other-- what would it be at my cyclones or just before my hay filter??? Wouldn’t those location change the vacuum. I have a vacuum hooked to the area containing the grate. I think that is about where everyone has theres (?)
Wow what great wood drying weather we are having. If it only wasn’t so hot so I could get out and cut some more. Cut some 3-4 inch Box Alder yesterday. They were standing and when I chunked them, I felt water on my hand when I got near the end. It rally fracture well and today it is dry. TomC
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Interasting. Same happens to my Seat. What culd be the reason?
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a little servo motor / coil, on your gas throttle…
It also rev’s up when cold…
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It is my understanding that the TPS drops to 1000 rpm then fine tunes itself by incremental changes from the computer TomC
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We use to have a little solenoid that bumped the throttle open a little when the key was turned on, to up the idle. When you turned the key off the solenoid retracted and closed the butter flies to stop the engine from chugging on after shut down. It was kind of dieseling if any fuel dribbled into the hot engine. TomC PS Koen I read your post again and you are correct the motor / solenoid does control the throttle, but directly inside the throttle body. And yes it is for increase rpm when cold. Sorry I didn’t quite read correctly. TomC
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I have only an old fasion stop screw on the throttle and a cold engine soleniod valve on a bypass hose, which I’m not even sure is working.
Without my WK string my idle varies a lot with gasoline/woodgas, woodgas vacuum ratios and rich/lean mixture.
Also I have a very plastic and variable dashboard. Requires constant adjustment of my WK string tension 
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Hi, All!
A lot of those variations are easier to handle if you handle gas and air with equal conditions.
Equal conditions you will achieve if you let the motor vacuum, which for part load and idle is the dominant pressuredrop available, be the decisive factor for dispensing both gas and air!
Chris has made a series of videos describing the automixer, and testdriving. Last summer, probably in August.
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Yes the dash on mine is not stiff. If I ease my foot on the accelerator and adjust my screw, it is ok. But then when I give it gas with the peddle and let up it pull the cable tight and bends the dash a little. I’m not familiar with the VW fuel system. I know it is different from most. Does it even have a TPS on it? TomC
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No, no TPS. Only a micro switch which bypasses lambda when full throttle.
This is an old but very informative video of the K-jet.
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Thank you. Very informative and well done. And it sounds like many places that could go wrong over year of use, but for what we were talking about I am wondering if the auxiliary air valve that goes around the butter fly?. There seems to be a cavity there that could become blocked and prevent air for fast idle from getting around. Just me being an instant expert after watching the video, Sorry TomC
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I agree. I’m amazed anything works.
I’ve thought about that too, but I’m not sure that valve works at all. My idle is crappy on gasoline and rpm is all over the place, warm or cold.
But on woodgas, and the right setting on the WK-string, it’s steady as a rock 
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Hello Mr. Tom .
I never thought it would ever get hot enough here in Alabama to put on pajama bottoms . The last few days I am beginning to consider trying it . Only problem is I don’t remember ever owning any 
The trucks are doing just fine and working hard in this heat but this old man has to work about half fast 
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I can’t work more than half fast after that coma … I’m still busy … Cut brush most of yesterday … Baked a pile of potatoes and roasted some corn this evening (on wood) … Talk on the phone … Mike
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Mike, you know that you are going to have to come to Argos 2017. Wouldn’t you like a ride in a woodgas DeLorean?
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That is kind of my point. If that isn’t working or is plugged, it should run crappy on gas or wood. The WK string is just opening the butterfly and letting the are into the engine that the valve is suppose to be allowing to then engine. Besides simply being plugged, they said something about an electrical motor or pump in that line. It really puts that smile on your face when you can just lift off the gas pedal and things go right. I have been using my left for for both clutch and brake and over revving with the accelerator coming up to a stop sign. I know Max has an answer and Chris built one but is it correcting the problem we are talking about and Chris put a lot of effort into that build.
Cut down a big tree today and saved quit a few limbs for chucking. Good drying weather for the next few days so I’ve got to get in there and “get-er-done”. It is that Box Alder which I thought was a relative to maple, because it has “whirly bird” seeds but my logger savior today informed me it “ain’t too good a wood” for burning.— my answer-- it"s wood. He then offered to take a couple of 8 ft logs that I have for fire wood and make 2x2’s on his band mill. I’ve got to make nice with him!!! TomC
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