Fuel injection engines and woodgas

I have read on the GEK site that an inline switch for the injectors is necessary in order to convert a fuel injection engine to run on woodgas. Does the fuel pump need a cutoff as well? Where would I find a diagram of the engine intake retrofit; woodgas in with valve configuration and air in?

Hi Joe, welcome to the site. Yes you will need to shut off the fuel pump at minimum, and for TBI injection also switch off the injectors.

Diagrams, videos and detailed discussions of the Keith gasifier are available in the Premium area of the website. If you’d like to sign up just contact me here: http://driveonwood.com/contact


I can run the truck on 100% woodgas without shutting off the fuel pump, only need to shut off the injectors. However it was mentioned to me that if I leave the injectors on and only turn off the fuel pump that gas will still be sucked into the intake manifold due to the high vacuum produced by the engine (this could be advantageous in some circumstances). However I have not placed a switch inline with the fuel pump so as I could turn it off to test this.

I am playing with the idea that if one spliced in a rheostat inline with the injectors fuel could be tapered manually to run duel fueled when needed, I will be trying this soon but as of yet I am unsure whether it will work or not. There are members running rheostats inline with their fuel pumps and manually adjusting the amount of gasoline that gets to the intake manifold that way (however they are running multi-port fuel injected vehicles)

The injectors would need a PWM type adjustment, I don’t think you can just lower the voltage to them.

Also, dual-fueling is a bit dangerous to the gasifier, because it will mask signs of trouble and allow you to overpull the gasifier indefinitely, where it would normally just run out of power and stop. Better to switch over completely if needed and give the gasifier a rest.

Chris, Thank you for your reply. I have been considering signing up for a few days now. I have another member encouraging me to do so. I am tired of dumping money in to projects that do not pay off. I will be able to sign up in a sew weeks. By then I should make a decision. I am ready and willing to do the work, I just want it to be worth the investment.

Dustin, I am planning to convert my 2000 Dodge Dakota with a 4.7 liter v8. If I am right I think it has multi port fi. You insight may prove to be quit valuable. Let us know what you find out with your experimentation. Thanks.

TBI is throttle body injection, right? My project vehicle is a 2000 Dodge Dakota with 4.7 liter v8. I believe it is mpi - Multi port fuel injected.

yes you are correct, list of abbreviations: http://driveonwood.com/learn/abbreviations-and-acronyms

Most likely the 2000 dodge is MPFI - multiport fuel injection, Wayne goes into depth about how to tweak these to run on woodgas as these are the style of gas delivery/engine he has chosen to work with.


“The injectors would need a PWM type adjustment, I don’t think you can just lower the voltage to them.”

I wasn’t sure how exactly the computer increased/decreased the amount of fuel delivered but what you stated might be a likely case. won’t take much to splice in a rheostat to see what it does. Otherwise I think I will have to splice the rheostat between the fuel pump relay control and ecu like what has been done before.

Hello Joe,
A couple of thoughts for ya.
I haven’t seen any one convert a 4.7 yet… It is considerably different from a 5.2 or 5.7.
It has 2 plugs per cylinder and coil packs as well.
and no Distributor
Seems to have good horsepower.
I think it might a good engine… Don’t have a clue whether the computer will give enough advance.
Sounds like Wayne and Steve Unruh could chime in.
It could be a real good Woodgas engine.
Welcome to the site.

Hey Joe,
I messed up! I thought the 4.7 was a cam in block design, doesn’t look like it in the pictures.
Looks like an “over head cam” definitely not my first choice for Woodgas!
Very sorry for the mix up.

I have some limited experience working with a pwm with HHO. Thanks for the info.

Good info, and thanks for the mopar link.

Hey Joe,
I messed up! I thought the 4.7 was a cam in block design, doesn’t look like it in the pictures.
Looks like an “over head cam” definitely not my first choice for Woodgas!
Very sorry for the mix up.

Hello Terry, Joe and all.

I haven’t chimed in because I really don’t know what to say. Steve U has made some very good post concerning the above and I have been looking for them.

I personally have no experience with the OBD11 but the research I have done say the year the manufactures switched from OBD1 to OBD11 in most brands is 95 to 96. Sean has the 96 dakota and he loves it but he said it is an obd1. Terry L and Richard C have 97 and 98 year models and all seems positive.

I know of one person that has gasified an obd11 of a different brand. He (or she ) has had a lot of trouble with it and says will never try another obd11. Lot of trouble with sensors and other equipment that has to be modified and does not want to go public because some agencies might frown on the modifications.
Also I am told the fuel pump is either on or off, no adjusting.

Maybe I should just start with my Honda generator as I originally intended. I do have a multifuel regulator and carb mixer for it already. It also sounds like my 2001 Lumina is also not a good candidate if it has the obdII. Mr Keith, I am inspired by your accomplishments, thank you for posting.

“Otherwise I think I will have to splice the rheostat between the fuel pump relay control and ecu like what has been done before.”

Is the rheostat between the relay and ecu or between the relay and fuel pump?

Thanks Mr. Joe and welcome aboard Sir.

Sigh. As a fellow never driven a mile in woodgas I’ve been trying to not post onto vehicle threads anymore.
Most all of this has been covered again and again but Admin Chris tells me Searches will not work for the Premium side things been discussed already.
But on the 4.7L Mopar and general fuel injection and even Onboard Diagnostic II areas I do have actual on-hands experience.

The 4.7L V-8 and smaller 3.7L V-6’s are single overhead cam interference valve into piston crashers designs. Good engines with only the early 4.7L having some with valve seat insert dropping out and camshaft brakage problems. Individual cylinder heads can be R&R’ed without front end timing chain removal IF you have the special chain and gears locking tools; you are VERY good; and you DO NOT MAKE A SINGLE OOPS MISTAKE.
Actually been many overhead cam engines gasified and ran now but ONE system dial-in, operator training. or fuelwood experimenting TAR mistake it’s going to cost you lots of time and money to fix the stuck open valves crashed damage.
These engines and almost all “modern” engines now have plastic intake manifolds and upper air plunums.
SOOT cleaning!! You will not be able to use a WK burn out method without damaging the plastic manifolds. So, Full teardown and an off the vehicle manual clean out then. Get a air compressor and air tools and learn to work fast and c-a-r-e-f-u-l-l-y not to strip and break plastic things. OR use one of the high tech material, expensive, multistage hot and dry bag type filtering system like Mr Vesa Mikkonen evolved into and promotes.

OBDII was a hatfull of system capability requirements the US EPA mandated onto the manufacturers. System performance and just the diagnostic plug, certain pin location and now 6-10 different communication protocols were mandated. Everything else was left up to the individual manufactuters how they met these mandated demands. Yes: initially madated to be in place by 1996 with transtioning actually over occuring 95-96-97 due to trade offs and even some plain model by model penalty paying. These are ALL why no one work-around hardware or software will ever work. Won’t even work with a single vehicle model like all Ford Rangers or all Dodge Dakota’s due to twice revised OBDII requirements, expected upcoming mandated electronic skid control; and manufactures playing an enternal keep up with tech electronic capabilty upgrades.
One mandate was to now have individual cylinder misfire detection. PO0300 random cylinder misfire no longer good enough. So all manufacturers to meet this did have to go to individual “port” fuel injection. Later individual independent controlled cylinder spark for stricter and stricter emmision tiers. Some did these transitions years earlier than the mandated dates for the better bragging rights emmisions, power and fuel economy.
Another OBDII mandate was for the system to be self testing/monitoring and reporting for failures and tampering.
IF you live in a mandated inspection area; or move into one; one moves into you; or sell this vehicle into one, your modifications will be found and that vehicle unable to be licenced and then legally driven there.
I can 90% of the time on-hands, if allowed to do what’s needed, AND personally take the vehicle myself through a pre-setup, warm-up drive and testing station pass-through beat the test on an OBDII vehicle. (My bit of “Screw the Gov’Mint” “bootlegging”. I only do this for shut-your-mouth family) BUT I CAN’T GET THEM PASSED PACKING AROUND GROSS VISIBLE MODIFICATIONS.

Outside one of these inspected areas and with no problem with that part of it, you will just then be fighting with the demands the onboard installed OBDII system will make for smooth engine performance. Later the system, the more toutchy this gets. These things do a lot of wide range self-controlling trying to see what they were programed to look for ON SPEC GRADE GASOLINE FUEL.
ALL newer Chryslers hate Bosch 3 and 4 Platium electride spark plugs. Love thier Champions and NGK’s. I am a 70’s, 80’s been burnt Champion plug hater. I had to learn to bend on this to get Dodges to run and control properly.

OBDII are being woodgased done now. Later OHC valve crasher engines will have to be done too. It will all be a wicked, expensive individual model by model learning expereince. You will then become the experienced “expert” on woodgasing that engine with that control system version. We will all be asking you then.

Not all modern fuel injection system are pulse width modified. Robert Bosch CSI and a few others as an example like a failed Crysler spray bar type were already highly varing fuel pressure delivery controled. Screw with these causes control system crashes.
MOST though do depend on an assumed (not sender monitored) steady regulated fuel pressure and vary the fuel delivered by How Long the electromagnetic injector is held open - Pulse Width (in time held open) types. Lowering the supply voltage then pressure can cause the injector too often to just not to snap open at all. Pressure regulation with pump voltage works great on these if the earlier, simpler OBDI. OBDII, many of them when the oxegen sensor feedsback sees an out of program range and they will shut off all of individual injector fuel flow and some even go into individual cylinder spark shutdown to put you into low power limp-in to “Save the catalytic!!” converter barely runs mode. Cat converter saving was an original OBDII mandate that expanded after a handshake agreement trade-off later between the manufactures and the EPA that the manufacturers for other concessions now had to warrantee Cats for an extened period out to 8 years/80,000 miles. The manufactures were then very much making thier systems shutdown sensitive to save them warrantee money. You generally must pay for the tow-in yourself.

So . . . many using later systems are going to be finding out just what manifold intake forced through soot cleaning into the exhaust is going to be doing on these later model Cat systems with OBDII, eh??
Also many of these later model engines have oil pressure driven variable camshaft timing “phasers” and variable displacement cylinder pair shut down for mileage like the Mopar pushrod Hemi V-8’s and the Honda V-6’s and are proving VERY oil viscosity sensitive so say my families experiences. How sensitive are these going to be to into the engine oil woodsoot migration??
We will be learning these as we go along. A Necessity, as the old simple die off and rust away by, by into scrap heaven.

Steve Unruh

Good Morning Mr. Steve,

Thanks again for the post and spreading light over some very gray areas .

I have got to figure out a way to isolate , store and be able to recall all your post . Just like E F Hutton , when you speak we all should listen and also remember.


One way to see all Steve’s posts (or anybody’s) is through their profile page. http://driveonwood.com/user/126/posts

Ouwiee! Fellows again you give me way too much credit.

I am coming up on a year here and have my favorites of you all that I faithfully follow and learn from all of the time.
Wayne’s your recent old description how you used to pre-char you fuelwood chunks for your earliest driving jet-less FEMA systems has been an inspiration this winter. Duplicating this has allowed me to up the usable performance on one particular troublsome grate-less in a fireplace airtight hearth woodstove. Ha! Ha! Change the fuel characteristics to match the system deficits! Turned me 180 around in my approch to it.
MikeL and John Stout are always pushing the envelope of driving operable building on shoestrings with obtainium. MikeL has now sworn off of aluminum out in the woodgas cooling end of it with pictures of why.
John Well’s, RonL’s and a few others carburetor gasification works here show that this still can be functionably goodnuff’ done as well.
The actual now OBDII gasifing fellows in MikeL, Bruce and Sean Frence, TerryL’s? and now some of others new recent up and running fellows is showing great progress in will works vehicles posibilties. I am having to revised my opinions constanly with all of the real in world put up info experiences.
And simple practical just build it up and learn for yourself - do it Charcoalman GaryG always a joy for me to follow.

The newer post 2000 vehicles are the future you younger fellows willl be having to step up into to keep vehicle gasification going strong.
A necessity.
Again my advice for now is to stay away from any of the the starting in `~2003 to the majority now current Controller Area Networked (“CAN” on your scanner says this - it does not mean Canadian!) buss communication vehicle systems. This will be ALL of your Hybrids including the GM full sized hybrid pick-ups, ALL the newer low sulfur needing auto diesels. ALL of the trottle by electrical wires only vehicles having NO more actual mechanical cable anymore.
New Teckers among you will have your work cut out for you on these.

Steve Unruh