[Mpower]

Originally Posted by chetanhanda

I was also coming to that conclusion that :
1] Due to lean mix it is causing my ECU (after getting input from my 02 sensor) to increase the STFT, which after sometime is pushing my LTFT to 2.3%.
2] Meanwhile also in parallel due to the lean mix the engine is knocking and triggering my knock sensors to inform the ECU to retard the ignition...

1. Your assumpiton is correct. Lean mix could be caused by injector clogging like Rocam mentioned.
2. Why dont you log data from the knock sensor too. That will confirm if it is knocking. Are you using Hondata?
3.How many miles on the car? Is it showing CEL or throwing any codes? since its a 1.6, I'm assuming its the 95 -99 model year which leads me to believe its close to 160K kms.

Originally Posted by chetanhanda

ok, I'll explain further my question :

Im getting LTFT readings varying from 1.6 to 2.3 % indicating that the AFR is lean.
1] At 0% throttle angle my LTFT is 0
2] At about 30% the LTFT climbs to between 1.6 and 2.3

I also observed that the ignition was
1] 12 degrees at 0%throttle
2] went upto 20 to 30 degrees at 30% of throttle
Im considering negative = ignition Advance(BTDC) and positive = ignition retard (ATDC)
looking atthe above values I was asking if lean mixture means ignition retard , so in other words High LTFT = ignition retard in order to stop knock.

2. Sounds normal. timing is advanced at higher rpms
3. If I'm assuming right, you have a major misconception. All ignition values are BTDC almost never is it ATDC. Retard means lower number BTDC and advance means higher number BTDC.....which leads me to believe that your engine is perfectly normal. BTW, do you have a copy of Honda's ignition map to confirm that the timing is deviated from normal? HOw did you conclude that you timing has been retarded.

[Steeroid]

I had to have a couple of pegs before I could understand whats happening here. Very interesting - thanks Mpower its beginning to make sense now.

[chetanhanda]

Thanks !

Originally Posted by Mpower

1. Your assumpiton is correct. Lean mix could be caused by injector clogging like Rocam mentioned.

I got a complete engine,injector, throttle body cleanup from the dealer
and it has made a +ve difference

Originally Posted by Mpower

2. Why dont you log data from the knock sensor too. That will confirm if it is knocking. Are you using Hondata?

I have a knock sensor on the car but my logs are not querying that sensor

Originally Posted by Mpower

3.How many miles on the car? Is it showing CEL or throwing any codes? since its a 1.6, I'm assuming its the 95 -99 model year which leads me to believe its close to 160K kms.

No codes are being thrown at all, my DTC scanner is not reporting a single code
The car was hardly used, just 8K miles per year

Originally Posted by Mpower

2. Sounds normal. timing is advanced at higher rpms

My timing is being retarded at higher rpms...

Originally Posted by Mpower

3. If I'm assuming right, you have a major misconception. All ignition values are BTDC almost never is it ATDC. Retard means lower number BTDC and advance means higher number BTDC.....which leads me to believe that your engine is perfectly normal.

Dude, plz, Im not such a newbie also
I know that BTDC will display -ve values(Advance) on my logger and ATDC (Retard)will indicate +ve values on my logger. I was getting +values
so Im sure it is retarding at higher loads due to some problem

Originally Posted by Mpower

BTW, do you have a copy of Honda's ignition map to confirm that the timing is deviated from normal? HOw did you conclude that you timing has been retarded.

The sticker under the hood indicates the correct ignition timing
also the Honda guys gave me a xerox copy of their datasheets after a long discussion over my laptop based readings.
Also just to confirm I was not interpreting values incorrectly I spoke to the software team who made this scanner and they say +ve=retard in the logs

[chetanhanda]

Thanks !

Originally Posted by Sideways

Have the MAP sensor checked.

1] Ok, I can read those values at Idle,midrange and WOT and compare it with ideal/standard values ..
I did not think of MAP as yet..
2] Hey sideways guess what u are right about inspecting TPS
I just remembered it says 9% instead of zero with my foot of the pedal, even at idle it stays at 9%
What to do abt this ? is this doing something...plz suggest what needs to be done about this ?

[chetanhanda]

By the way guys...this is off the topic
.. I just installed a ANSA sportcompact Silverline tunable axle back muffler(you can tune back pressure with a set of 2 allen keys)
I was also worried that the previous owner replaced the exhaust but installed it with a muffler from a LX version or something from a low end car. It used to make a loud rasping sound at as low as 15-20 MPH...seems it was too restrictive and car felt sluggish
seems the new axle back has made the car more free, definately the mileage, mid range and top end has improved..I can feel it

Now back to original thread .......
Based on feeback from u guys
1] I need to look at MAP and TPS (sideways)
2] Confirm if im reading ignition values right (Mpower)

[chetanhanda]

Originally Posted by Steeroid

I had to have a couple of pegs before I could understand whats happening here. Very interesting - thanks Mpower its beginning to make sense now.

.. ya , pretty detailed

[Mpower]

Originally Posted by chetanhanda

Dude, plz, Im not such a newbie also
I know that BTDC will display -ve values(Advance) on my logger and ATDC (Retard)will indicate +ve values on my logger. I was getting +values
so Im sure it is retarding at higher loads due to some problem

The sticker under the hood indicates the correct ignition timing
also the Honda guys gave me a xerox copy of their datasheets after a long discussion over my laptop based readings.
Also just to confirm I was not interpreting values incorrectly I spoke to the software team who made this scanner and they say +ve=retard in the logs

Only time it should retard so much is during cold start for the quick light off catalyst.

The sticker on the hood is base timing. PGM FI has a 3D map for timing.

[chetanhanda]

Originally Posted by Mpower

Only time it should retard so much is during cold start for the quick light off catalyst.

Ok, I will again check

Originally Posted by Mpower

The sticker on the hood is base timing. PGM FI has a 3D map for timing.

Ok.I dont have that, any place I can get hold of that ?

[Pankaj401]

Ok.I dont have that, any place I can get hold of that ?

try the link www.pgmfi.org.

[chetanhanda]

Originally Posted by Pankaj401

try the link www.pgmfi.org.

Its more of OBD-1, couldnt get much info

[Pankaj401]

What model is your civic?

[chetanhanda]

Originally Posted by Pankaj401

What model is your civic?

1.6 Ltr Vtec Coupe.
Engine number = D16Y8

[Pankaj401]

which model year is it?

[chetanhanda]

Originally Posted by Pankaj401

which model year is it?

year 96
---------------------------------------------------------

[Ford Rocam]

Originally Posted by chetanhanda

year 96
---------------------------------------------------------

1.6 Ltr Vtec Coupe.
Engine number = D16Y8

Your engine must be running OBD-2a (U.S Spec) your car must be civic EX Coupe with P2P ECU please confirm.