You are right Marvin I thought of that after I posted. The old trucks fuel lines were under vacuum rather than press.ure
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Rick, glad to see you are doing the Caddy!!
Mine was a 91 4.9, may be different, but I shut fuel completely off by running wire out of fuse box to toggle switch and then fused that wire!
In my opinion it needs a shut off from gasifier or it will run crappy, it’s pulling such weak gas specially at first that it’s just missin with your mixture, put a valve in it then you know if you have fresh air or woodgas!! There’s enough other stuff to worry about!! Good luck buddy!! Herb
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Rick Kind of what the others have said. I have a TBI and I use one switch to shut off the injectors. ( with mine if you shut the gas off but leave the injectors on, the engine will syphon or pull gas up to the TBI and the injectors will put it into the cylinder and you will be running on “hybrid” without knowing it). Then as Herb said, I went right to the fuse box an found the fuse for the fuel pump. Took the fuse out and attached a wire to one pole of the fuse socket, ran that to a toggle switch and then back to the fuse box’s other pole. I also put a fuse in the new line. Now I also have the “dash light dimmer” reostat in the line but as I said it is not slowly changing the voltage so that I can regulate the speed of the fuel pump.TomC
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Hi Don,
Whoops, I guess I should double check all my assumptions. Somehow I got the impression that the rheostat was for controlling the voltage to the injectors, not the pump. I have made a thankfully unsuccessful attempt a year or so ago to wire the rheostat accordingly. Then I just put a switch in the fuel pump line figuring I’d do the rheostat in the injector lines later. Now I should be able to install the rheostat easily in the fuel pump line.
Thanks,
Rick
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I also put toggle switches on both banks because of siphoning!!
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That was a trick of old over the road truck drivers. On a diesel they routed the “return” hose through the cab and had a pair of vise grips handy to pinch the hose off. This made the pressure in the injector pump keep building pressure and increasing the fuel supply and thus the speed. Particularly out in the southwest where they ran for miles with out a town. TomC
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Interesting, Tom. Another aspect of diesel engines I learned recently is that the diesel engines greater torque compared to gasoline engines is the diesel injectors’ ability to inject fuel throughout the power stroke as opposed to the one shot of fuel at or just before the start of the gasoline engine’s power stroke. I wonder if this difference will disappear with the introduction of direct injection gasoline engines which could also inject throughout the stroke.
Today I built and installed a bracket to mount the cable for advancing and retarding the timing mechanically as needed. Also am installing a butterfly in the rear of the woodgas line under the rear bumper. I ordered cables for both last night, they should be here by early next week. I will also look around and try to find my dimmer switch rheostat so I can put it into my fuel pump line.
Thanks,
Rick
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Rick, I have been stymied with mounting a rheostat to control the fuel pump. I think you my have the same problems as I so I am recommending you look up a discussion on PWM for fuel pump control in the premium section. 90% of what they talk about is over my head, so I doubt if I will benefit from it but you on the other hand I’m sure can understand it. TomC
Hi Tom,
I am flattered by your perhaps misplaced confidence in my understanding complicated discussions but unfortunately I have let my premium membership lapse. One person that I feel would be all over this subject is Mike LaRosa. I remember he made his own rheostat for his Cavalier out of some kind of spring (nichrome wire?) and a nail or something similar. He also seems very comfortable with electricity issues and concepts. Have you heard from him lately? I have not.
Maybe another approach to slowing the pump down would be to just add a number of different resistors to the line, perhaps selecting them with a rotary switch.
Rick
Rick,
I talked to him at Argos this year. Didn’t get to say good bye because some kind of youth gang worked him over and he left early right before backing into Ron’s tractor.
I’m trying to get over the flue and ultra busy/OT at work.
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Hi Rick I don’t want to be derogatory towards Mike L, I have learned from him, but his way of doing something is with bailing wire and bubble gum. You are right about him making his own, but it was just a piece of wire that he varied in length until he got a resistance that would work. Like any piece of wire that is hooked to the posts of a battery it got very hot. From reading what the guys are saying the rheostat does work sort of. In my case the rheostat does not give me a consistent increase or decrease in resistance as it should. In other cases, for guys that run hybrid very much the rheostat gets too hot. From the premium section, I believe it is ok if I say they are going to PWM. If I understood anymore than that, I’d probably spill my guts to you because I feel you and I have grown together in woodgas. But past knowing they are using PWM, they lost me with FET and “P” and “N” Like with rheostats some people through a PWM into the system and it sort of performs. But the gentlemen who know what they are talking about are actually building there own from info that they are sharing on the premium side. I missed Argos this year and I think they had some discussion on them down there. I’m trying to get in with a computer repair guy in hopes that he might be enough of a technician that I can have him build me something based on the discussions that have been posted. Good luck and go ahead with your rheostat until someone can explain the better way TomC
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Hi Tom,
I had to look up PWM to understand what it was. It seems like a better way to vary the power to a motor, it doesn’t waste power as heat like resistors do. I’ll have to look more into it before I can figure out how to use it.
Thanks,
Rick
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Hi Tom and Jeff,
Yes, Tom, I feel like we got into woodgas about the same time and followed similar paths, for example the LaRosifier. Mike was very helpful to me in getting something together that worked, even though it might only work briefly. I share his taste for the use whatever is on hand to do the job approach. He seems very knowledgeable, or at least more knowledgeable than me, about electronics and electricity in general, he probably could concoct something with PWM with bubble gum and baling wire as you say. And he is a very colorful person, never a dull moment with him around. I hope to hear from him soon.
Rick
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Hi Rick, Tom,
Finding the “correct” PWM for your car might be the only worry. It all depends your original wiring, which cable from the fuelpump is connected to the original switching in the computer. ( i try to keep it simple)
It seems that some folks are doing very well with using the electric brake control for trailers, it works on a similar way as a PWM but has the correct type of wiring.
Also, using another approach, similar as the pair of pliers on a diesel return line, use a pressure relief valve on your fuel pressure/injection line will do the trick. Ad an fuel pressure gauge and off you go…
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How about getting a little more sophisticated and for the butterfly valve, use and electrical solenoid. Might be better than a long cable. TomC
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Brake controllers are pretty cheap (around $25) and work good. Wire it inline sort of like a rheostat. If you want to try that way I’m sure we can get you through it.
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Thanks, Koen,Marvin and Tom,
I will look at the brake control approach. Of course I just gave one away a month or so ago when I was cleaning out some stuff I had left over after selling a big trailer I had last year. Oh well, $25 isn’t bad.
Tom, I already ordered the 12’ cable, but, yes, I had thought about the solenoid approach, too. Also for the timing advance. But I decided to use what I was familar with instead.
Rick
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OK, I looked on ebay to see what’s available. I found several types to pick from. There is the general electric brake control, the timer electric brake control and electric-hydraulic control. The timer models tend to be less expensive, the electric-hydraulic more expensive. Is one type easier to use to control the fuel pump with?
Thanks,
Rick
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There is one that has been used successfully. The timed one are a little easier than the inertia based ones.
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Would the controller with digital read out work better to see how much power is going to the pump.
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