JrRifleCoach

After weeks of testing, calibrating, recalibrating, checking for vacuum leaks, repairing cracks in the exhaust manifold, pressure testing the cat and parts swapping.... also reading the posts here, I found something that actually works to increase mileage.

My 92 4.0 AT has 108K on the clock and the PO bragged about his getting 22-26MPG. I use this daily as a service vehicle for my business averaging 200-250 miles a week.

Since most of my driving is local around town with some open road time, the best my foot could do was 17. I first checked the FP and replaced the filter. No change. So a set of reman Bosch Gen 3 injectors. Bumped me up to 19 until the cooler weather set in and MPG's dropped to 15. Lots of posts discussing Winter fuel blends convinced me that this was a reasonable explanation for the big drop in MPG's. Not willing to give up to the gas gods I rechecked calibration of the sensor array and replaced the oh-two sensor just because.

That's when my reading on HHO generators started. (If your interested search HHO on youtube) But one of the fuel adjustments for an HHO conversion is to trim the MAP sensor voltage to lean out the fuel map with the addition of HHO. I found a nice package here (http://www.hydrogen-generators-usa.c..._enhancer.html) that was less $$ on ebay.

Since my MPG records have been well documented, the gizmo was spliced into the MAP control line to the ECM and I filled up the tank. It took a few days to tweak the trim until I was comfortable. First thing I noticed was how much better the heater worked. I gained 25 degrees of water temp. That now runs at 190-200 within the first 15 minutes of operation. (yes - new 195 t-stat)

The cost of an EGT or AFR gauge is not possible at this time, so I'm making the adjustments based on a vacuum gauge and my butt-o-meter and staying on the rich side for now.

After the first 100 miles the tank was topped taking 5.5 gallons.
I ran two more tank fulls of combined city/hwy netting over 600 miles before posting the results. My new MPG average is hovering at 19.2 MPG.

Looking forward to finishing the TC lock-up switch and Springtime when the fuel quality is better.



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BeepBeepImaJeep

thats awesome i was hoping to get better mpg outta mine when i did,plugs,oil,oil filter,airfilter,fuel filter,o2 sensor but its still not very good, i know it has a strong gas smell still when running, my header is cracked pretty good so i think thats whats causing it but im not sure...

Hommersimpson

there is a way to check afr with a digital multimeter... but i cant find the artical right now... maybe someone eles might know how...

A_Jeepr

i reguarly on long trips get ~23 mph......

on a daily basis, combined 20% city 75% rural and 5% idling when i first start it up i guess. i am getting ~19 mpg. right on the money! i can live with that!

zedpapa

a good stand alone AFR meter is reasonably priced. i got one from Summit for about $275 that came with a gauge.

http://www.summitracing.com/parts/INN-3795/

looks like the price has come down again. if you gained 25* coolant temperature, that could mean you are running lean. i would definitely get it checked ASAP.

zedpapa

zedpapa

A Jeepr, thats the mileage i get in my 89 2dr 5spd. i guess the french knew what they were doing, huh? although mine isn't exactly the way it came from the factory.

zedpapa

A_Jeepr

swapped a ax15 tranny i blew the french one up

jstantherprsn

HHO lol That's the biggest sham. They try to justify science of its efficiency. Splitting water consumes so much power (electrically). Its the most inefficient form to create hydrogen ever, literally. All your doing is using a tank of water and your alternator to split water into hydrogen and oxygen. Your better off tanking a tank of hydrogen putting a regulator on it and have it trickle h2 into your airbox like a ghetto nos system. If you believe in it fine but I'm not arguing with science you won't get.

There was a news station some time ago who tested bought systems and installers lol. It was a scam no increase in mileage, there was an actual decrease in mileage (because your loading the alternator more). The more load you add to an alternator the harder it is to turn. Its the reason why on gensets you don't want to drop alot of load fast or it will overspin until the governor and all slow it down. So save your money.

JrRifleCoach

Thanks for the advice. But this is not about HHO.

My topic is about trimming the fuel map to return to OEM economy.

So many out there have the same problem and this is a cost effective fix.