jon,
i found this very interesting.
http://www.carcraft.com/techarticles/electronic_fuel_injection/index.html
--- On Wed, 9/15/10, jon@dakota-truck.net <jon@dakota-truck.net> wrote:
> From: jon@dakota-truck.net <jon@dakota-truck.net>
> Subject: Re: DML: Re: K&N fipk
> To: dakota-truck-moderator@bent.twistedbits.net
> Date: Wednesday, September 15, 2010, 1:27 AM
>
> MICHAEL CABE <mikecabe@prodigy.net>
> wrote:
>
> > Mike,
> > I replaced the whole stock air box with the K&N
> setup . It just
> > seems that it is dogie and falls on its face like a
> lean condition .
> > I see no gas mileage gain . I put new plugs in at the
> same time as
> > they were shot . I used champion iridium plugs .
>
>
> You changed 2 variables at once, so its not
> possible to blame the
> K&N without first eliminating it or the plugs from the
> equation. The
> FSM says that the 4.7L is equipped with copper core plugs
> from the
> factory and warns that preignition will result if another
> type of plug
> is used. I'm not familiar with the Iridium plugs, but
> they could very
> well be the cause of your problems. Frankly, the
> fancy spark plugs
> usually cause more trouble than they are worth, and that
> might be the
> case in your situation. Its a bit of a hassle to swap
> plugs, but one
> thing you could try is to put the stock intake system back
> on, and if
> the truck wakes back up, that could be an indication that
> the problem
> is indeed the K&N. If not, it might be the
> plugs. Did you gap them
> to .040"?
>
>
> > The truck has about
> > 62000 on it .It idles smooth as silk and cruises fine
> . I think it
> > sucks too much air .
>
>
> With an EFI system, it isn't really possible
> to suck too much air
> - the engine will only use as much air as it needs,
> regardless of the
> flow capability of its intake tract. Unless you're
> using some sort of
> forced induction, I would not expect the engine to lean out
> simply
> because the intake has more flow capability.
>
>
> > I have had the K&N setup on it for about 3000
> > miles I would think it would have learned by now .
>
>
> Probably, but if you did not disconnect the
> battery during the K&N
> install, I'd recommend doing it now, just to make sure the
> computer is
> starting out from scratch.
>
>
> > The truck has no
> > mass airflow sensor or an air temp sensor .
>
>
> Unless you have modified the engine from
> stock, the air temp
> sensor is located in the intake manifold, near the left
> side of the
> throttle body.
>
>
> > After I installed the
> > fipk i read an article some where I don't remember
> where that said
> > without a mass airflow the computer doesn't know what
> to do with the
> > xtra air and could create a lean condition .I just
> wanted to know if
> > anyone had heard this or had the same problem Mike
> Cabe
>
>
> No, a mass airflow sensor is not necessary -
> our engines use the
> speed density system which uses a manifold pressure sensor
> and engine
> RPM as inputs to a lookup table to calculate fuel
> requirements. The
> oxygen sensor compensates from there (within certain
> limits) to keep
> the air/fuel ratio right. A K&N intake is well
> within the operating
> parameters of the stock programming and will not lean it
> out.
>
> Also, you mentioned that the truck feels
> "dogie" and falls on its
> face. I assume this is during hard
> acceleration? Under those
> conditions, the truck is in open loop and the stock fuel
> mapping is so
> rich that there's no way a K&N intake could lean it out
> to that
> degree.
>
> It sounds like there is something else going
> on here. Possibly a
> sensor which wasn't plugged back in or got knocked loose
> during the
> install. My gut is telling me to suspect those spark
> plugs. Since
> swapping the intake out is really easy, my recommendation
> would be to
> slap the stock intake back in there and see if the truck
> goes back to
> normal. If not, I'd yank those plugs and install a
> set of the
> recommended copper core plugs. (Champion RC12MCC4, or
> possibly the
> Champion 4071 truck plugs)
>
>
> --
>
>
> -Jon-
>
> .- Jon Steiger -- jon@dakota-truck.net
> or jon@jonsteiger.com
> -.
> | '96 Kolb Firefly, '96 Suzuki Intruder,
> Miscellaneous Mopars |
> `-------------------------------- http://www.jonsteiger.com --'
>
>
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