Dakotas: Return vs Returnless fuel systems

Interesting Chris. I had to look back and find the hybrid video Wayne did and it was with the Ram. V-10 hybrid driving - YouTube
Makes me wonder if the 94-95 Dakotas act the same.


Do you all switch the injectors off or let them click? Would that make a difference with return or returnless?

Good Morning Marvin .

I’m glad you started the topic. It all makes more sense to me now after studying the above .

The 92 -93 does OK with hybrid driving and the computer will adjust but only if you keep the throttle at a constant . It only takes a little acceleration or deceleration to throw the air / fuel ratio out of balance . This must be because the manifold pressures will affect the fuel pressure regulator setting.

On the other hand seems like the 94 and 95 that I have tried does much better with hybrid driving. There seem to be a tolerance for a moderate amount of acceleration and deceleration and still maintain the proper air mix settings.

I’m sure I will be putting some of the above hybrid techniques to use tomorrow . I plan about 350 miles with the V-10 with trailer and load .

Don ,

I never cut my injector off, just the fuel .

Hi MarvinW
On your “why?” EGR, to some with no EGR.
Just like the two line to one line returnless change then they needed LESS parts to design, spec-set, bid-proposal-let, contract-out, source ship in, install and then warrantee sweat.
Youbetcha, they would do anything possible to remove the need for a pita failures EGR valve system.
EVERYTHING you said: plus the refinement of two-way dual bed catalysts systems. The FIRST cat bed added in then as an thermal/chemical pre-REDUCTION section splitting back out the undesired the in engine cylinder heat and pressure combined air nitrogen/oxegen (then nitrous oxides combinations) back into just nitrogen and oxygen. This HOT freed up oxegen then flowing directly delivered into the rear catalyst OXIDIZER bed to help burn up any engine flowed out remaining unburnt hydrocarbons. Notice most all manufacturers had eleiminater the even more pita failures prone seconadery air pumping system also?! They no longer had to force pump outside air to the Cat for oxidation burning. They could then even go back UP the compression ratios and ignition timing set-ups producing MORE engine power and made Nox’s as then an oxegen “delivery” carrier to the cat system. Took expensive development of these REDUCTION Cat sections beds. Took the availibilty of the rare earth metals to make these Cat beds. Changes in South Africa; and the Soviet Union collapses allowed this.
Took much tighter managing computors controlling to make these dual bed calaysts system live, working, functional and remain mandated 80,000 miles compliant.
Any manufacture unable to do this level of reliability engineering when bankrupt: AMC, IHC. Jeep only saved by multiple buy-out/sells being traded around.
Deep pocketed Ford and GM learned to stop hating emissions top-down mandates and learned to use these deep dollars engineering barrels to market kill off, or lock out of the US competitors unable to annty-up and $'s keep up: Fiat, Renault, Citroen.
Financially squeezed others into cheap buy-out positions takeovers: Rover, Jaguar, Saab, Volvo.
Remember that these games do get rigged, and thumbs tillting is rotten rife from the tops down.
WE the ones ultimately paying for all of this. Why I do not mind at all tilting some of these “What is good for xM, xoeing, xOxD, General xxxtric is good for the Country”. Are all absolute B.S. windmills blow-hard hot air popcorn.

Woodgasing converting if it will work for you without pinging be-jesus on gasoline; and you are out of inspected mandated compliance areas try going without the EGR system. Later the systems with more advanced OBD II computor systems the more likely to driven into computor detected and then limited power and gears “limp-in” driving.
No EGR would mean for you too, less things to have to fix and keep working.

Steve Unruh

My 95 runs is returnless, and runs great on hybrid. If the PWN is gradually increased, the computer will cut back on injector pulse width when too rich. While driving to Indiana, I could cut fuel ump voltage back to 4.7 and it would run normal, but lack a little on the hills. If you remember Chris, the fuel pump test at Argos, it appeared the pressure was a function of PWM voltage, about 45psi max. I would like to monitor fuel pressure, but can’t afford the remote sensing gauge, and don’t want a liquid fuel line on my side of the firewall.


It’s starting to make a little sense. I’m wondering if your already under the pressure of the regulator with a light switch or pwm and put vacuum to it if it will stay the same or still change some. I’ll have to break the fuel pressure gauge out when I get things going.


On the Ford I just dial the pump back. Don’t do anything with the injectors.


Thanks for the egr info. While were on the fuel subject, we all know running to lean on gasoline is bad. Have you seen any engine damaging effects from running lean or rich from woodgas? It seems to not matter either way until the point the engine won’t run anymore. I think I would have fried the poor old Ford by now if you could but thought I’d ask anyway.

I’ve wondered what the “octane rating” of woodgas would be. Don’t seem to be able to get a ping from the Ford as long as it has even a little bit of woodgas mixed in. Even just enough to leak past a sloppy valve.


Tested fuel pressure tonight, ala Carl Zinn with the A/C pressure gauges. Smart idea Carl! Found out several interesting things.

[EDIT: I realized just now, I did this test with the vacuum hose to regulator disconnected. Shouldn’t affect anything but normal run pressure. Will retest at some point with hose connected.]

  • Normal running pressure seems to be 40 psi on a return system (at least mine). Sitting still it’s at 30 psi. 3 Key off and on cycles will bring system from 0-30.

  • pulling a full vacuum on the regulator brought it down to 28 psi. No significant engine changes, still running normally. This is not enough adjustment to be worthwhile.

  • When dialing back my brake controller, it’s (I’m guessing) about 3/4 way off before I see any pressure drop. All the drop happens in that last quarter turn, pretty linearly.

  • Engine leaning out varies directly by fuel pressure. Starts to lean out around 20 psi. About 10 psi is where I like it for blending in woodgas. 5 or less it will barely run.

  • I found this new info very helpful! Now I want another gauge on my cluster. Will be researching adding fuel pressure to instrumentation.

Do you think an oil gauge would work with the possibility of ethanol present in the gasoline?


How well do you think the voltmeter works for gauging fuel pressure? I was thinking about putting one in.


This would work too to if you want to monitor fuel pressure

Without looking any further I would like to think that you can get a transducer that has the right connection for the fuel rail.

Good Morning MarvinW
No I have not seen any engine ill effects from running woodgas lean.
But admit not doing that much. The small sationary systems that Iam inviled with are set up to be gasifer batch fueled ran. Air/fuel mix gets set to run on any woodgas out after engine starting up mix fiddling. Engine change then used as a low on wood fuel signal to refuel the hopper.
Vehicle guys here North America and Finland/europe with exhaust oxygen sensor feed back systems may be able to answer your question.

Steve Unruh

Just ordered this:


and this:


The sender provides 0.5 - 4.5v output, and measures to 60psi. Since my max pressure is 40 psi, I will get perfect resolution out of the 0-3v voltmeter. If I get fancy later, a 0-5v signal is perfect for driving a feedback control loop.

EDIT: Steve, Marvin, I can confirm running lean woodgas seems to be OK. No pinging and 10K miles with no issues. Gasoline has to run rich to cool the motor and prevent pinging - woodgas doesn’t have these issues.

Chris beat me to it but I was going to suggest that there is a correlation between the voltage and the output fuel pressure sensor. The trick is just getting the correct resolution or do some form of scaling. For the OBD-II fellas. Mode 01 PID 0A formula A*3 is your fuel pressure.

Ohhh. Forgot your woodgas “pinging” ask.
Never heard this either. Unlikely to hear this. Woodgas proven now to be useable easily 11/1 cr up to 17/1 cr. Depends on the bore/stoke/rod length ratios and the actual combustion chamber turbulence shaping.
Beneath all of the “idea selling” oversimplifications most things end-up being connected and interrelated.
The scientist’s back in the late 1960’s trying to beat back the California LA basin severe yellow smog found that by bleeding into the air and gasoline mix a small percentage of inert gas that they could reduce the in the engine cylinder temperature and pressures thereby reducing Nox formation. Reducing the T/P also reduces the power, but that was not their priority. They used singly and in combination inert carbon dioxide, argon and even pure nitrogen. Not feasible to required cars to have mandated high pressure tanks of inert modifying gas. Some One of them figured out that in the engine exhaust stream they had plenty of on-board, already engine made carbon dioxide and passed through unaffected air nitrogen. So = EGR systems. They had previously directed the engine engineers designers to be looking at compression ratio reducing and igntion timing set backs for decreases in the cylinder T/P’s and Nox forming. All killing power.
Tight balancing act juggling what had to be done to decrease unburned hydro-carbons HC’s and carbon monoxide CO versus what was needed for nitrous oxides Nox reductions.
This balance was best found to be in at a tightly controlled stoicalmetric A/F gasoline ratio. So developed O2 sensors -> computer processors -> and on and on with Cats -> later port EFI -> and now variable controlled valve timing.

Well woodgas making creates a percentage of unconverted carbon dioxide and system air-in unaffected passed through nitrogen in the woodgas supplyed stream out. So should not be surprising having great pinging moderation effect.

Octane rating are best discovered and set with special variable compression engines. Called the “M” (for motor) method. The “R” research method is a calculation. Look on the actual gasoline dispensary fuel pumps and is will say R + M / 2. Ratings added together by both methods and then averaged out to keep both system camps happy. Works for some spark ignition liquid fuels. Works poorly for most spark ignition gaseous fuels.
Woodgas would like diesel, need a different rating system. As yet undeveloped.

Rating systems are needed only for Top-Down centralized distribution systems anyhow.
Made in place, used in place the real user concern should be, “Is it doing the job for me?”

A personal comment.
I broke with the clean up engine emissions folk when the communists/socialists eco-greens took over and declared then early 90’s that carbon dioxide was now “The Devil” engine exhaust gas that needed to be controled. This is very bad engine and combustions fuel science. This IS directed social controlling.
The Priests of Green now praising hyrogen as the future fuel to push. Vilify anything with carbon in the fuel as “Baaa,-a-d”. Say this enough, long enough, and then the Sheeple will start Baaa-a-ding bleating too!
They are s-t-o-p-i-d-l-y insisting now that the earth is flat and AGREE!, or we will persecute you. You, you, unbeliever, you.
I strongly feel now in my system operations that MORE IC engine shaft power is being made with carbon chained soots fed in then with the hearth made hydrogen.
I push for as much hopper/hearth made CH4 methane as possible at the expense of woosie energy weak hydrogen gas. Only need just enough H2 hydrogen for the real in-cylinder combusion buring rate up moderation to offset the slow burning carbon monoxide fuel component.
And make the IC piston engines eat as much very energy dense carbon soots as it can handle.
I am not an engineer or a scientist. Formal High School level educated only. A LOT of college, tech schools supplemental classes then actual in-field worked off of those. I have no wish to be peer published and recognized, or win a Noble Prize.
For me the proof of my wood carbons soot and made methane as the best of the engine fuels in the mix is in the superior useable shaft horse power that guys like WayneK and others here like Sean French have been able to now prove.
I’m old American. Eat my dust. Push, pull, or get the hell out of the way.

Steve Unruh

Ha! Now my late edit. (I compose and type slow)
Chris this carried on belief that gasoline has to be ran rich for pinging “cooling” moderation is really, really at the last used 40’s, 50’s, early 60’s early only a hotrod street and track way to do this. At the expense of trashing your fuel economy and making really stinking exhaust. By the late 30’s OEM’s know that lead in the fuel, and more lead was the easiest way. Even short track roundy-rounder racers by the late 70’s had figured out that lean and hot was better for the balance of power versus pit re-fueling stops to win with. 40’s aircraft learned carried over water/methanol cooling was the way to go if you just had to.
Overfueling will overheat and melt destroy catalytic converters faster than any other way! Over-fueling will certainly spike your exhaust out HC’d and CO’s!!!
Over-fueling to in cylinder cool, IS NOT BREATHING NIEGHBOR COOL, and hasn’t been for on the road use for 55 years. Die myth devil! Die!

Great info guys. Ian answered the question of is it already there? Only on OBDll? Darn. Wes found the gauge I was looking for, and Chris bought one. More to come I’m sure.

Here’s a couple of pictures for you. Looks like the only easy place to hook in is by the fuel filter or test port. everything else seems to be quick connects.

Thanks Marvin. My 0-3 voltmeter just arrived from China, so I’ll be looking at that project sometime soon.

I’m in Nashville and would like to meet with you sometime.
Call me will you, I know you sent me your number way back via email but I don’t have access to them! Please call me 515-778-6466
Herb Hartman

I’ll give you a shout tomorrow Mr. Herb.