Fw: [Diy_efi] Lumpy engine in closed loop cruise

[Lee M. Lemoine]

With a turbocharged car, a lot of times light load crusing is right below
"absolute zero" so to speak... only a light bit of vaccum, which really is
'almost boost' so to speak (if the turbo wasn't there, there would be lots
more vaccum)

-- LL

On 10/21/05, Mike <niche at iinet.net.au> wrote:
>
> At 04:12 PM 10/21/05, you wrote:
> >I think what is happening here is a misunderstanding of "cruise". My old
> brain may be behind the times,
> >but to me 85 MPH is a bit over cruise. (unless it's an F1 or CART -
> tongue in cheek).
>
> Thats really only 136 Km/Hr, bit fast for the freeway I guess,
>
> When I used to go country in the olde ford escort with 1600cc I used to
> happily
> 'cruise' at 140 to 150Kms/hr, no turbo, not even WOT, somewhere around
> 75%,
> so his setup with some boost suggests his valve timing might be out or
> he has a reasonably serious exhaust restriction...
>
> Looking forward to doing my block tomorrow with kids, depending on what
> I find I just might really do my block !
>
> <chuckle>
>
> Rgds
>
> Mike
>
>
>
>
>
> >Geoff H
> >
> >
> >----- Original Message ----- From: "Mike" <niche at iinet.net.au>
> >To: <diy_efi at diy-efi.org>
> >Sent: Friday, October 21, 2005 1:57 PM
> >Subject: Re: [Diy_efi] Lumpy engine in closed loop cruise
> >
> >
> >>At 12:19 AM 10/21/05, you wrote:
> >>>Why to you say it is heavy load ? they is almost no boost. 0.3 bar max
> which is nothing really.
> >>>Throttle is about 5-10% so the turbo is just ticking over.
> >>huh ? Did I miss-read when you said:-
> >>
> >>"In 5th gear, trying to hold steady 85 mph, 3500 rpm, MAP about 100-130
> kPa"
> >>
> >>Am I correct in seeing that as absolute manifold pressure at that cruise
> ?
> >>
> >>To me that says you are at close to atmos pressure in your manifold to
> >>keep it at 85mph, thats a fairly high pressure for cruise - isnt it ?
> >>
> >>>How do I richen it up, that is one of my problems. If you can the VE
> tabels will the BLM not pull it back.
> >>
> >>Dont know anything about your ECU, maybe aftermarket performance
> >>people can help. However, I have occasionally had similar problems,
> >>came down to electrical connections on air flow meter, the ECU
> interpreted
> >>this as faulty and switched in and out of limp mode.
> >>
> >>If the car is more than 5 yrs old really worth checking connectors,
> often
> >>just cycling them (plugging in and out a few times) can help diagnose.
> >>
> >>Other thing that occurs, make sure all your low voltage leads
> >>are well away from your high tension (EHT) . A common problem on the
> Nissan
> >>engine used here in the commodore is the cyl 1 ignition lead being
> really
> >>close to the crank angle sensor leads and the tags breaking so there
> >>isnt the normal separation, this allows high tension voltage noise to
> >>get imposed on low voltage signals this can cause ECU to misread
> >>crank signals, in your case make sure the MAP is not being misread
> >>because any high voltage leads cannot corona discharge influencing
> >>the main sensors. On one forum in Australia we had one guy who went
> >>through 4 crank angle sensors - suffice it to say - he didnt know having
> >>good EHT leads right next to low voltage leads would or could be an
> issue
> >>ie. Even brand new good leads allow some corona effect...!
> >>
> >>Fortunately its not as if its plasma ignition, that would be far worse
> >>
> >><chuckle>
> >>
> >>Rgds
> >>
> >>Mike
> >>
> >>
> >>
> >>>Dermot
> >>>
> >>>
> >>>
> >>>>Bit of a heavy load for cruise,
> >>>>
> >>>>And yes does sound a bit lean, can you richen it up by
> >>>>20% and observe the effect ?
> >>>>
> >>>>Rgds
> >>>>
> >>>>Mike
> >>>
> >>>
> >>>Regards from
> >>>
> >>>
> >>>Mike
> >>>Perth, Western Australia
> >>>VL Commodore Fuse Rail that wont warp or melt !
> >>>Twin tyres for most sedans, trikes and motorcycle sidecars
> >>>http://niche.iinet.net.au
> >>_______________________________________________
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>
>
> Regards from
>
>
> Mike
> Perth, Western Australia
> VL Commodore Fuse Rail that wont warp or melt !
> Twin tyres for most sedans, trikes and motorcycle sidecars
> http://niche.iinet.net.au
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>



--
Sincerely,

Lee M. Lemoine
http://www.turbochargedsoul.com/
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