TOPIC: Dan Merricks fuel vaporizer and mpg recipe

TBW, correct? [Throttle By Wire] or Cable driven?. Don't know if you remember, but my TB [cable driven] has adjustable butterfly valve stop. I cranked the adjuster in so that way ~98% of the air flowed past the plate instead of through the IAC. That made a big difference, granted i have very little vacuum now and can't rely on engine braking as much.

Check to see if if the TB is adjustable, if TBW it might be possible to reprogram (quite possibly expensive and impossable without custom ECU) or modify the TB for desired results.

Also we are now operating on winter gas, switched to midgrade and solved issues (damn fuel injectors) and bumbed milage considerably, right now 36mpg or more.

Ryker (Medtactics), sounds like you are getting kinks out of your Saturn. From talking to Scott, there wasn't time to do any mods to the IAC system. So, did you open the throttle stop by turning in the stop screw? Curious to know why ya did that. What change did that give, an increase in idle RPM's?

Scott, maybe increase to aspirin dosage?

As I'm always trying to learn, if there were pics available of both Ryker's and Scott's TB's it might be useful. I may go looking online to get an idea of what Ryker's TB looks like.

I have always done the IAC and PCV mods as ways to further boost Manifold vacuum, our basic tactic.

Tracy G

Medtactics wrote: TBW, correct? [Throttle By Wire] or Cable driven?.

To be accurate, and to aid in communication of accurate info, it's considered "Fly by Wire".

Medtactics wrote: Don't know if you remember, but my TB [cable driven] has adjustable butterfly valve stop. I cranked the adjuster in so that way ~98% of the air flowed past the plate instead of through the IAC. That made a big difference, granted i have very little vacuum now and can't rely on engine braking as much.

For most vehicles, once the IAC valve is cleaned and fully operational (the carbon from the PCV bulds up, reducing their mobility) the IAC becomes less of an issue than may be thought. Eliminating it is not recommended, but reduction-DRAMATIC reduction-in the size of the opening is advised. Most 8 cylinder engines only need a hole of 1/8" to function normally.

Medtactics wrote: Check to see if if the TB is adjustable, if TBW it might be possible to reprogram (quite possibly expensive and impossable without custom ECU) or modify the TB for desired results.

The much-beloved EPA mandated sealing the adjustments off after a certain year. The caps can be removed safely, although it may be problematic, it can be done (I have many times.). With Fly-by-Wire, the adjsutment process is managed rather effectively by the ECU. Follow the instructions in the conditioning process and you'll see it work itself out. Just be patient! If you try to rush the process, you could-and probably WILL- get throttle body error codes and a ck engine light.

Medtactics wrote: Also we are now operating on winter gas, switched to midgrade and solved issues (damn fuel injectors) and bumbed milage considerably, right now 36mpg or more.

The switch to mid-grade and the resultant increase in mileage is most likely due to the vaporization rate of your fuel. This is tied directly to the fuel chemistry, which varies greatly from state to state. California has the WORST fuel chemistry in all the states that I've visited since becoming Gadgetman. I lost 100+ miles per tank going from Arizona to Cali.

You gotta LOVE CARB!

Now, in this case, I would recommend making an exhaustive examination of the entire intake system for potential accidental and engineered leaks, and reducing all to the limit of your comfort.

Be BOLD!

Be DARING!

Be a Gadgetman!!!



Ron

Scott Castleberg wrote: Okay. Topped off tank today. No change in mpg. 15.9 mpg.

I can feel the groove effect every time I hit the gas, but my mpg gains have been stubborn.

Just being honest.

While I'm sure the mention was made elsewhere, it makes things easier to know the year, make, model and engine size. With that data, I can usually come up with a solution to the mileage woes. And 15 mpg IS a "mileage woe", no doubt!

So post that in this thread (again if it's already there) and I'll see what I can figure out for you.

I'm tickled pink to see you back, Scott!

I missed a good man...

Ron

Yes, it has been a while.

My truck is a 1999 Silverado, 5.3 vortex.

Mileage at 224,000

New O2 sensors about 2 years ago, when I installed my version of Dan Merricks vaporize . Still did not get any better mpg. Fuel trims did not drop like they did on our olds silhouette.

My wife now drives a 2012 equinox with ecotec engine. Have not touched that one, mod wise.

I already checked with propane, Saturn engineers were their own sanctioning body in devoloping the engine, they had zero outside influence and they made their motor the best it can be on such a limited budget without cutting any corners, these small aluminum engines last forever and a few people are now making it to the 1/2 million mile mark on orginal parts. All the after performance parts are basically clones of the factory system, but polished, honed, and/or clay extruded. That is how well designed it is.

My problems are with fuel injectors being used with 87 octane fuel and heat soaking after being driven grandma style in a city below 25mph and has never been beyound any speed limit for over half its life, don't blame the car, blame the driver who never drived it.

Scott Castleberg wrote:
I can feel the groove effect every time I hit the gas, but my mpg gains have been stubborn.

Maybe this is the problem, punching the gas?

I get my best mileage when (from a stop) I smoothly get on the gas to a specific rev range (1500-2000 rpm works for me, and that's 1000-1500 rpm above hot idle), and then hold it there til I've achieved cruising speed, at which point I get off the go pedal and throttle back for cruise. at that point, it's a matter of a feather's weight of pressure to maintain speed.

My brain says this gets the waveform from the groove happening in the intake, the ECU working on injector pulse widths (fuel trim) while the transmission sorts out what's best (it hops from 1st through to 3rd pretty quickly, and then settles in 4th when I throttle back for cruise).

The tires don't chirp, torque doesn't snap my neck or slam me back in my seat, but it gets me ~40 MPG combined, which is about double what GM/the gubmint says I should get. I'd bet you can achieve similar results.

At such low RPMs your are wasting fuel (granted i don't know your powerband) , now obviously punching it waste fuel too. The trick is to ease it into the powerband swiftly and smoothly as possibly, granted with an autotragic thats near impossible unless you have some form of foot technique.

Now torque is the exertion of force and horse power is the efficiency of fuel being used to its potential. For intance my torque band is 1000 to 6500rpm, and power is from 3500 to 6500rpm, one of the main reasons why saturn gets more fuel efficient the faster you go.

I think my power band is in the 800-2500 range...I cruise nicely on the highway at 1700-1800. Can feel the groove between 1100 and 1500. Passing on an uphill stretch on the highway requires 4000+, briefly. 500 miles from 18 gallons of 89octane E5 is what I usually get, give or take.