Honda Car Forum

Hello,

My 95 Civic ESi (Philippine domestic version) is similar to the U.S. EX
version, I think. It has a PH16 engine (PGM-FI, 16Valve, 1.6Li, SOHC
non-vtec, ECU code P27) but has no oxygen sensor. This is common
knowledge here, and there is a plug where the sensor should be. My
question is, is this a great disadvantage in terms of mileage? Average
mileage for civics here is 18 to 24 MPG (~8-10km/liter).

Is the ECU always running in open loop mode? Can we somehow buy an O2
sensor and put it in, and if so, will this buy us much MPG-wise?

Thanks so much in advance.

sharx333 wrote:
> Hello,
>
> My 95 Civic ESi (Philippine domestic version) is similar to the U.S. EX
> version, I think. It has a PH16 engine (PGM-FI, 16Valve, 1.6Li, SOHC
> non-vtec, ECU code P27) but has no oxygen sensor. This is common
> knowledge here, and there is a plug where the sensor should be.

really? can you post a pic? it's hard to imagine the point of running
fuel injection absent the sensor because without it, the ecu doesn't
know for sure how much gas to inject.

> My
> question is, is this a great disadvantage in terms of mileage? Average
> mileage for civics here is 18 to 24 MPG (~8-10km/liter).
>
> Is the ECU always running in open loop mode?

presumably.

> Can we somehow buy an O2
> sensor and put it in, and if so, will this buy us much MPG-wise?

presumably, but you may need to do extensive wiring mods. it could save
you significantly in gas.

>
> Thanks so much in advance.
>

double check on this "common knowledge" thing - i've never seen any
electronic fuel injection system that doesn't have a sensor - without
it, the ecu is "blind". check both sides of the cat as well as in the
manifold. it would be amazing if one wasn't there somewhere.

jim beam wrote:

>
> double check on this "common knowledge" thing - i've never seen any
> electronic fuel injection system that doesn't have a sensor - without
> it, the ecu is "blind". check both sides of the cat as well as in the
> manifold. it would be amazing if one wasn't there somewhere.


Interesting. Early fuel injection systems sold in the US were indeed
open loop designs, such as the Bosch D-Jetronic which was installed on
many late 1960s and early 1970s era Volkswagens and Volvos. Closed loop
came into general use about the same time as three way catalytic
converters did. Late 1970s and onward.

I suppose that it is possible that car makers built open loop versions
for countries without emissions regulations much later than the 1980s,
but I have no idea how it was done or if it is possible to easily
convert such systems to closed loop operations.

John

Hello again and thanks for the replies. I've posted photos at this
link, if you're interested:

http://hondaswap.com/ecus-electronic...24/#post698583

I think this version (ESi, Philippines) is a "stripped-down" version,
if you will, of the EG 4-door coupe (92-95) with a D16Z6 engine, minus
the VTEC. I've been using the service manual for some time now, and all
other parts match. The manual doesn't say anything about other O2
sensors though.

This may have been done to make it more affordable, even though at the
time this was the top-of-the-line model here. Also, the emission laws
here aren't as strict as in the U.S., and back in the early '90's they
were even less so.

Am I missing something here?? Are our civics "crippled"?






John Horner wrote:
> jim beam wrote:
>
> >
> > double check on this "common knowledge" thing - i've never seen any
> > electronic fuel injection system that doesn't have a sensor - without
> > it, the ecu is "blind". check both sides of the cat as well as in the
> > manifold. it would be amazing if one wasn't there somewhere.
>
>
> Interesting. Early fuel injection systems sold in the US were indeed
> open loop designs, such as the Bosch D-Jetronic which was installed on
> many late 1960s and early 1970s era Volkswagens and Volvos. Closed loop
> came into general use about the same time as three way catalytic
> converters did. Late 1970s and onward.
>
> I suppose that it is possible that car makers built open loop versions
> for countries without emissions regulations much later than the 1980s,
> but I have no idea how it was done or if it is possible to easily
> convert such systems to closed loop operations.
>
> John

sharx333 wrote:
> Hello again and thanks for the replies. I've posted photos at this
> link, if you're interested:
>
> http://hondaswap.com/ecus-electronic...24/#post698583
>
> I think this version (ESi, Philippines) is a "stripped-down" version,
> if you will, of the EG 4-door coupe (92-95) with a D16Z6 engine, minus
> the VTEC. I've been using the service manual for some time now, and all
> other parts match. The manual doesn't say anything about other O2
> sensors though.
>
> This may have been done to make it more affordable, even though at the
> time this was the top-of-the-line model here. Also, the emission laws
> here aren't as strict as in the U.S., and back in the early '90's they
> were even less so.
>
> Am I missing something here?? Are our civics "crippled"?

it certainly looks that way! john raises the good point about
pre-catalyst injection systems not having sensors [i'd forgotten that -
it's /so/ long since i've seen one!] and you've posted the pics. but it
still amazes me. the cost of a sensor, in bulk, to a manufacturer has
got to be less than $50. it's astonishing that honda would elect not to
use one - maybe there was a legal reason.

getting back to your original question, you can almost certainly
retrofit, but there will obviously be wiring involved and it would
probably require acquisition of a new ecu. interesting project though!
and you may as well go for the vtec while you're at it!

>
>
>
>
>
>
> John Horner wrote:
>> jim beam wrote:
>>
>>> double check on this "common knowledge" thing - i've never seen any
>>> electronic fuel injection system that doesn't have a sensor - without
>>> it, the ecu is "blind". check both sides of the cat as well as in the
>>> manifold. it would be amazing if one wasn't there somewhere.
>>
>> Interesting. Early fuel injection systems sold in the US were indeed
>> open loop designs, such as the Bosch D-Jetronic which was installed on
>> many late 1960s and early 1970s era Volkswagens and Volvos. Closed loop
>> came into general use about the same time as three way catalytic
>> converters did. Late 1970s and onward.
>>
>> I suppose that it is possible that car makers built open loop versions
>> for countries without emissions regulations much later than the 1980s,
>> but I have no idea how it was done or if it is possible to easily
>> convert such systems to closed loop operations.
>>
>> John
>

John Horner wrote:
> jim beam wrote:
>
>>
>> double check on this "common knowledge" thing - i've never seen any
>> electronic fuel injection system that doesn't have a sensor - without
>> it, the ecu is "blind". check both sides of the cat as well as in the
>> manifold. it would be amazing if one wasn't there somewhere.
>
>
> Interesting. Early fuel injection systems sold in the US were indeed
> open loop designs, such as the Bosch D-Jetronic which was installed on
> many late 1960s and early 1970s era Volkswagens and Volvos. Closed loop
> came into general use about the same time as three way catalytic
> converters did. Late 1970s and onward.

you're absolutely right.

>
> I suppose that it is possible that car makers built open loop versions
> for countries without emissions regulations much later than the 1980s,
> but I have no idea how it was done or if it is possible to easily
> convert such systems to closed loop operations.
>
> John

John Horner <jthorner@yahoo.com> wrote in
news:49MMg.2566$xC3.1076@trnddc06:

> jim beam wrote:
>
>>
>> double check on this "common knowledge" thing - i've never seen any
>> electronic fuel injection system that doesn't have a sensor - without
>> it, the ecu is "blind". check both sides of the cat as well as in the
>> manifold. it would be amazing if one wasn't there somewhere.
>
>
> Interesting. Early fuel injection systems sold in the US were indeed
> open loop designs, such as the Bosch D-Jetronic which was installed on
> many late 1960s and early 1970s era Volkswagens and Volvos. Closed loop
> came into general use about the same time as three way catalytic
> converters did. Late 1970s and onward.
>
> I suppose that it is possible that car makers built open loop versions
> for countries without emissions regulations much later than the 1980s,
> but I have no idea how it was done or if it is possible to easily
> convert such systems to closed loop operations.
>
> John

Corvettes used to have a MECHANICAL fuel injection option(totally open-
loop),long before EFI came to be.

--
Jim Yanik
jyanik
at
kua.net

"Jim Yanik" <jyanik@abuse.gov> wrote
> Corvettes used to have a MECHANICAL fuel injection option(totally open-
> loop),long before EFI came to be.

Anyone remember the Lucas mechanical FI system? Wonderful when it worked
properly, a pig when it didn't, which was most of the time, being made by
Lucas ...

And some Peugeot 404's had a mechanical FI system too.

sd

Does it have a converter?

Al

"sharx333" <emil.santos@gmail.com> wrote in message
news:1157832403.971773.202940@i3g2000cwc.googlegro ups.com...
> Hello,
>
> My 95 Civic ESi (Philippine domestic version) is similar to the U.S. EX
> version, I think. It has a PH16 engine (PGM-FI, 16Valve, 1.6Li, SOHC
> non-vtec, ECU code P27) but has no oxygen sensor. This is common
> knowledge here, and there is a plug where the sensor should be. My
> question is, is this a great disadvantage in terms of mileage? Average
> mileage for civics here is 18 to 24 MPG (~8-10km/liter).
>
> Is the ECU always running in open loop mode? Can we somehow buy an O2
> sensor and put it in, and if so, will this buy us much MPG-wise?
>
> Thanks so much in advance.
>

Stewart DIBBS wrote:
> "Jim Yanik" <jyanik@abuse.gov> wrote
>
>>Corvettes used to have a MECHANICAL fuel injection option(totally open-
>>loop),long before EFI came to be.
>
>
> Anyone remember the Lucas mechanical FI system? Wonderful when it worked
> properly, a pig when it didn't, which was most of the time, being made by
> Lucas ...
>
> And some Peugeot 404's had a mechanical FI system too.

Look at any old diesel engine, particularly those on tractors and heavy
equipment... mechanical FI there as well.