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  #13  
Old February 24th 05, 10:52 PM
Mike Romain
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The only good thing about the FI is you can ignore tune ups longer. The
carb isn't quite so forgiving... ;-)

Mike

William Oliveri wrote:
>
> Sounds like I should trash my MPFI for a carb :-)
>
> "Mike Romain" > wrote in message
> ...
> > The 82 to 86 258 and the YJ's with the 258 all have a poor Ford attempt
> > at an emissions computer in them running the carb and the spark timing.
> >
> > This computer acts like an old fashioned governor and limits the rpm to
> > slightly over 3000 before it clamps down and the engine won't rev
> > higher.
> >
> > By modifying any part of the ignition or carb, this emissions computer
> > either gets removed or put to sleep or you get really ****ty performance
> > because it goes into 'limp home' mode.
> >
> > Adding FI kills the sucker and you get a FI computer with it's inherent
> > poor(er) gas mileage. The carb well tuned gets about 5 mpg better
> > mileage than the FI systems from what I have observed.
> >
> > Mike
> >
> > William Oliveri wrote:
> > >
> > > Mike, how would you kill the computer with MPFI and the jeep still runs

> and
> > > was this in your mind when you wrote that below?
> > >
> > > > New Fuel injection = kill computer = instant 25% power boost.
> > >
> > > bill
> > >
> > > "Mike Romain" > wrote in message
> > > ...
> > > > Well............
> > > >
> > > > I am running an 86 with an Accel SuperCoil for hot spark, the timing
> > > > advance 'ported', the stock Weber-Carter BBD carb unplugged and

> manually
> > > > set up, the 'Nutter Bypass' or no emissions computer working, stock
> > > > manifold with a straight 2" pipe back to a Dynomax 'Super turbo' high
> > > > flow muffler, 3.31 gears turning 33" mud tires. In Canada it is a
> > > > Utility vehicle and don't require a Cat.
> > > >
> > > > I get a sweet 23 US mpg running at 65 mpg and passed the last

> emissions
> > > > with 15 ppm HC and 0.16% CO.
> > > >
> > > > 1st gear will light up my 33's way too easy when turning onto a 40 mph
> > > > road so I have to watch the pedal, 2nd pulls 'fast' up to 50 mph

> turning
> > > > 4400 rpm, 3rd is the power gear and hauls hard up to 75 mph or so, 4th
> > > > buries the needle easy and no freakin' way do I want to find out how
> > > > fast 5th goes.
> > > >
> > > > My speedometer is exact according to many checks with a GPS.
> > > >
> > > > My total cost was about $45.00 for the Accel coil. The Nutter which
> > > > puts the computer to sleep cost a couple bucks for wire, solder and

> heat
> > > > shrink and gave me a sweet 25% seat of the pants power and mileage

> boost
> > > > with at least a 10 mph increase in each gear and the ability to

> actually
> > > > get the rpm up to the top at 4500 for the 'red line'.
> > > >
> > > > I think the biggest boost anyone gets from 'any' mod to the engine is
> > > > because the computer has to be put out of it's misery for 'any' mods.
> > > >
> > > > New carb = kill computer = instant 25% power boost.
> > > >
> > > > New Fuel injection = kill computer = instant 25% power boost.
> > > >
> > > > MSD Ignition = kill computer = instant 25% power boost.
> > > >
> > > > Or you can just stay stock and kill the computer = instant 25% power
> > > > boost!
> > > >
> > > > I wish you luck and will look forward to reading about the

> improvements
> > > > you hope for.
> > > >
> > > > If or when I modify anything I will pay close attention to performance
> > > > increases. I think my 2" exhaust could use a set of headers and a

> 390,
> > > > but my manifold isn't broke and my carb purrs so I have no urge to
> > > > upgrade it. It runs pretty sweet for me now..... :-)
> > > >
> > > > Mike
> > > > 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> > > > 88 Cherokee 235 BFG AT's
> > > >
> > > > CJ7 Casey wrote:
> > > > >
> > > > > I want to see how much emission legal power I can get out of my

> 258CI.
> > > > > Inline six with just bolt on parts. I will be doing that this last
> > > > > weekend in February 2005. Any one who has dealt with these
> > > > > modifications, any advice would be greatly appreciated, You can e

> mail
> > > > > me at
> > > > > Bolt on parts, Bolt on parts "They said it was easy, I'm hoping it
> > > > > is."
> > > > > I bought the Holley 390 cfm carburetor / the Offenhauser 4 bbl

> intake
> > > > > manifold / Holley fuel pump / Pace Setter headers / K&N filter /
> > > > > D.U.I. Distributor / Cintech wiring harness / 86 Wide track high
> > > > > strength axels and lockers / M.O.R.E. spring over, shackle reversal,
> > > > > lift kit...
> > > > > I will document these modifications to help any one it can, with
> > > > > problem foresight. Like I said any advice would be greatly

> appreciated.
> > > > > I will list all pros and cons I can find with these "bolt on
> > > > > parts". I will be doing all of this with no automotive experience,

> or
> > > > > back ground. Wish me luck, and If you know what problems to look out
> > > > > for, let me know.
> > > > > I will start documenting and posting full results and in the end it
> > > > > will be dino tested.
> > > > > With current stock engine problems I have created, and I've tried

> to
> > > > > fix, I'm getting 12 miles to the gallon and 84 horse power. I should
> > > > > be getting 17 miles to the gallon, and 115 horse power, if it ran
> > > > > properly. "they say to expect 250 horse power with all modifications
> > > > > and 10% better that stock fuel economy increase, They also said I

> might
> > > > > get 300 horse power out of it? They also said it's easy bolt on
> > > > > parts. I'll let you know.

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