Fw: [Diy_efi] Lumpy engine in closed loop cruise

[Mike]

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