Re: fifth-gear and miles per gallon [CIS-E]

["Chris DeLong" <green536@hotmail.com>]

ok well there is CIS Motronic and there is OBD Motronic. CIS Motronic works 
similarly to regular CIS-e. It has the same mechanical components but alos 
incorporates the ignition system all in one ECU. CIS-e for 16v's has 2 
separate computers for ignition. OBD Motronic does not have an air flow 
sensor plate. It has a heated wire sensor that measures inlet air volume and 
allows the electronic injectors to stay open for a longer duration depending 
on higher rpm's.

Chris DeLong
ICQ#45030867
Seattle, WA USA
'80 16V 'Rocco ragtop
'91 GLi 2.0 16V
'77 Rabbit 16V
'80 'Vert (parting out!)
'61 17 Window type II
'91 Vanagon
'78 Rabbit
'78 Rabbit (for sale)
'87 GTi 16V



>From: 16V Jason <jason@scirocco.org>
>To: "Marc Peterson" <mpeters6@rochester.rr.com>, <scirocco-l@scirocco.org>
>Subject: Re: fifth-gear and miles per gallon [CIS-E]
>Date: Wed, 31 Oct 2001 17:17:00 -0500
>
>At 04:48 PM 10/31/2001, Marc Peterson wrote:
>>Assuming no enrichment is used...
>
>Right...
>
>
>>All CIS/CIS-E engines mixed by the air flow meter flap.
>
>Right!...
>
>
>>   If the engine is
>>running at a given RPM, it is pumping a fixed amount of air though it, so 
>>to
>>my understanding 3000 rpm is the same amout of fuel whether it is 1/2 or 
>>3/4
>>throttle, the mixture doesn't change based on the throttle position.
>
>Oh! So close! :)
>
>You're totally right --mixture is determined by air flow sensor.  So the
>mixture (proportion of fuel per air) should stay relatively constant
>through the rev range.  However, at higher throttle openings, the engine
>moves more air, and thus more fuel.
>
>>This is different on Motronic system, obviously.  They have a throttle
>>position sensor.
>
>I'm not all _that_ familiar with Motronic, but I'd be surprised if all it
>had is a throttle position sensor -- doesn't it have a mass airflow sensor
>as well?  I'm pretty sure every single modern fuel injection system uses a
>mass airflow sensor to determine how much air is going in, and then
>correlates that with throttle position for a number of reasons (to richen
>mixture during abrupt throttle movements, full throttle enrichment, etc 
>etc).
>
>Jason
>
>
>
>
>
>>I think the above is right.
>>
>>Marc
>>----- Original Message -----
>>From: "Fry, Larry" <LEF@chem-tronics.com>
>>To: <scirocco-l@scirocco.org>
>>Sent: Wednesday, October 31, 2001 4:33 PM
>>Subject: fifth-gear and miles per gallon
>>
>>
>> > Hypothetical situation: you have fifth-gear ratio that gives 3800rpm at
>> > 80mph and it takes 1/4 throttle to maintain that steady speed.
>> > second hypothetical situation: you have, on the same car, on the same
>> > stretch of road, a fifth-gear ratio that gives 3000rpm at 80mph but it
>>takes
>> > 1/2 throttle to maintain that steady speed.
>> >
>> > question: which situation yields the best mileage?
>> >
>> > In other words, which influences miles-per-gallon more, rpm or throttle
>> > position?  Or is it pretty much a wash?
>> >
>> > Inquiring minds......
>> >
>> > Larry  sandiego16V
>> >
>> > [Disclaimer]This e-mail is strictly confidential and intended solely 
>>for
>>the
>> > addressee. It may contain information which is covered by legal,
>> > professional, or other privilege. If you are not the intended addressee
>>you
>> > must not use, disclose, or copy this transmission. This E-mail is not
>> > intended to impose nor shall it be construed as imposing any legally
>>binding
>> > obligation upon GKN Aerospace Chem-tronics Inc. and/or any of its
>> > subsidiaries or associated companies. Neither GKN Aerospace 
>>Chem-tronics
>> > Inc. nor any of its subsidiaries or associated companies gives any
>> > representation or warranty as to the accuracy or completeness of the
>> > contents of this E-mail. GKN Aerospace Chem-tronics Inc. shall not be 
>>held
>> > liable to any person resulting from the use of any information 
>>contained
>>in
>> > this E-mail and shall not be liable to any person who acts or omits to 
>>do
>> > anything in reliance upon it.
>> >
>> >
>> > --
>> > Email LIST problems to: scirocco-l-probs@scirocco.org.
>> > To unsubscibe send "unsubscribe scirocco-l" in the message to
>>majordomo@scirocco.org
>> >
>> >
>>
>>
>>--
>>Email LIST problems to: scirocco-l-probs@scirocco.org.
>>To unsubscibe send "unsubscribe scirocco-l" in the message to
>>majordomo@scirocco.org
>
>
>--
>Email LIST problems to: scirocco-l-probs@scirocco.org.
>To unsubscibe send "unsubscribe scirocco-l" in the message to 
>majordomo@scirocco.org
>


_________________________________________________________________
Get your FREE download of MSN Explorer at http://explorer.msn.com/intl.asp


--
Email LIST problems to: scirocco-l-probs@scirocco.org.
To unsubscibe send "unsubscribe scirocco-l" in the message to majordomo@scirocco.org