Go Back   Team-BHP > Under the Hood > Technical Stuff


Reply
 
Thread Tools Search this Thread
Old 13th September 2007, 11:16   #46
Senior - BHPian
 
nitrous's Avatar
 
Join Date: May 2004
Location: UAE/Lon/Madras
Posts: 6,966
Thanked: 282 Times
Default

From what I know,
MAF =Mitsubishi.
MAP =Honda.
nitrous is offline   (1) Thanks Reply With Quote
Old 13th September 2007, 11:45   #47
BHPian
 
quicksilver's Avatar
 
Join Date: Oct 2005
Location: Coimbatore
Posts: 455
Thanked: 8 Times
Default

Quote:
Originally Posted by chetanhanda View Post
so you are saying the o2 sensor was mounted a bit more upstream so it may possibly disturb the idle of the engine ... ?
Sorry if I had not put it down properly... what I meant was, the Honda Technician felt that O2 sensor could have been mounted a bit shallow and not deep enough on the Headers. Again, he did not say it was faulty, but was just observing and commented that it MIGHT be so.

One thing I noticed though, on the OE headers, the sensor seems to be at a point where the exhaust pipes from all the 4 cylinders merge. On the greddy ones, the O2 sensor is on a single cylinder's exhaust. Theoretically, does this make a difference? I know it feels the same practically now...

GTO, I am glad you solved the issue and am sorry if I am hijacking the thread. Just hoping it helps add value to the discussion.

Last edited by quicksilver : 13th September 2007 at 11:46. Reason: formatting tags removal... before I get an infraction :)
quicksilver is offline   Reply With Quote
Old 13th September 2007, 12:01   #48
Team-BHP Support
 
Jaggu's Avatar
 
Join Date: May 2004
Location: Bangalore
Posts: 17,742
Thanked: 7,449 Times
Default

ECM resetting will take off rev limiter? thats a new info ???
Jaggu is offline   Reply With Quote
Old 13th September 2007, 12:09   #49
GTO
Team-BHP Support
 
GTO's Avatar
 
Join Date: Feb 2004
Location: Bombay
Posts: 47,723
Thanked: 88,962 Times
Default

Quote:
Originally Posted by Jaggu View Post
ECM resetting will take off rev limiter? thats a new info ???
Tell me about it! Psycho says that it happens sometimes. He knows of another stock Vtec with the same situation.
GTO is offline   Reply With Quote
Old 13th September 2007, 14:25   #50
Team-BHP Support
 
Zappo's Avatar
 
Join Date: Oct 2005
Location: Hyderabad
Posts: 5,648
Thanked: 1,997 Times
Default

Quote:
Originally Posted by GTO View Post
Psycho says this is due to the ECM reset. Whatever it is, who is complaining ?
And what is the redline for the OHC? Are you revving past the redline mark? This may not necessarily prove to be a happy happy situation in the medium to long run if you are not careful.
Zappo is offline   Reply With Quote
Old 13th September 2007, 14:28   #51
GTO
Team-BHP Support
 
GTO's Avatar
 
Join Date: Feb 2004
Location: Bombay
Posts: 47,723
Thanked: 88,962 Times
Default

7100 rpm was the standard limit. Wont go above 7500, though will have to cautious during "pedal to the metal" runs. I still cant figure out how the limiter is gone.
GTO is offline   Reply With Quote
Old 13th September 2007, 14:47   #52
BANNED
 
mclaren1885's Avatar
 
Join Date: Jul 2005
Location: Bangalore (the city of modded cars) !!
Posts: 4,821
Thanked: 28 Times
Infractions: 0/1 (10)
Default

The engine is capable of revving to 8,000 with stock valve trains. Though I am not so sure the stock fueling will be giving you power at that rpm.
mclaren1885 is offline   Reply With Quote
Old 13th September 2007, 15:18   #53
Senior - BHPian
 
veyron1's Avatar
 
Join Date: Mar 2005
Location: Mumbai
Posts: 1,426
Thanked: 37 Times
Default

Quote:
Originally Posted by chetanhanda
Even NA cars have MAF sensors, where did you get this idea that NA cars have to be MAP , some stock cars even have Alpha-n ...You cant make a rule NA= MAP..
I stand corrected. But then, I haven't seen Indian cars running MAF except for boosted petrols & diesels, which made me draw to that conclusion. I never said anything about alpha-n; besides, they run off of MAP.

I've seen the 'Vettes & some other high capacity N.A. engines run MAF, but I figured that was due to the cc factor, which necessitates the measurement of higher flow rates. I do not suppose I've seen a below 2-litre N.A engine running an MAF...or are there? Er....any Indian examples? I'm quite positive the Indian Lancer/Cedia runs MAP.

Quote:
Originally Posted by chetanhanda
Exactly opposite of what u are saying .....provided by the IACV...
Beg to differ. I've worked on some cars (example; Santro) where the ECM automatically went into "choke" mode upon detecting a faulty check valve sensor. Engines normally start in "choke" mode causing it to idle at 2-300 RPM above normal, which stabilizes after warming up. Replacing the sensors have rectified the fault- in the cases that I've seen.

Quote:
Originally Posted by Ford Rocam
There is something like Throttle Position Sensor or (T.P.S),....
Thanks, Jeetu bhai; very detailed explanation. I'm aware of the TPS functioning (although not of the voltage values and deeper specifics). I was also not aware that the ECM cuts off IACV snesor i/p's completely once the TB moves off of "0" position.
veyron1 is offline   Reply With Quote
Old 13th September 2007, 15:56   #54
BHPian
 
Ford Rocam's Avatar
 
Join Date: Feb 2005
Location: Mumbai-India
Posts: 880
Thanked: 16 Times
Default

Quote:
Originally Posted by veyron1 View Post
Thanks, Jeetu bhai; very detailed explanation. I'm aware of the TPS functioning (although not of the voltage values and deeper specifics). I was also not aware that the ECM cuts off IACV snesor i/p's completely once the TB moves off of "0" position.
Actually ECM sends out voltage to idle valve in terms of "Duty Cycle" like how its with "fuel injectors" for the idle valve to close/open depending upon various conditions like T.P.S,Engine rpm,Temp,etc.
Ford Rocam is offline   Reply With Quote
Old 13th September 2007, 16:54   #55
BHPian
 
Sideways's Avatar
 
Join Date: Nov 2004
Location: Madras - India
Posts: 641
Thanked: 18 Times
Default

Quote:
Originally Posted by nitrous View Post
From what I know,
MAF =Mitsubishi.
MAP =Honda.
Well, not entirely true. The Lancer runs a MAP while the Cedia runs a MAF.

The ECU learns on a continous basis. There are mixed opinions on whether or not ECU resetting is a good practice. When an ECU is reset all maps are erased and it takes atleast a minimum of 50 kms of running for it to settle on a base map. I strongly beleive - and this is my perosnal opinion, that ECU resetting is a waste of time, unless and until it detects a fault / error which when corrected needs the ECU to be reset.

About the limiter not kicking in due to ECU reset - Even I am hearing this for the first time. In my opinion it could be something else. Possibly the Cam angle or the crank angle sensor voltage, which triggers the RPM limiter in the ECU. Possible causes for malfunction might include a weak battery, in which case the problem will sort itself out automatically once the battery reaches optimum charge.

I dont think you need to worry. But try not to over rev.
Sideways is offline   Reply With Quote
Old 13th September 2007, 18:01   #56
Distinguished - BHPian
 
Mpower's Avatar
 
Join Date: Mar 2005
Location: Bangalore
Posts: 10,432
Thanked: 1,682 Times
Default

Quote:
Originally Posted by veyron1 View Post
I do not suppose I've seen a below 2-litre N.A engine running an MAF...or are there? Er....any Indian examples? I'm quite positive the Indian Lancer/Cedia runs MAP..
Most german cars are MAF. In India, that would be Corsa and Astra.
Mpower is offline   Reply With Quote
Old 13th September 2007, 20:09   #57
BHPian
 
chetanhanda's Avatar
 
Join Date: Mar 2005
Location: Toronto
Posts: 886
Thanked: 42 Times
Default

Quote:
Originally Posted by Ford Rocam View Post
There is something like Throttle Position Sensor or (T.P.S), a variable resistor connected to butterfly of throttle plate, when throttle is closed it generates "x" voltage say for eg: 0.45V that value goes to ecu as throttle is closed & the engine should idle so it activates I.A.C valve to routine idling operations. If there is dust accumulated due to carbon buildup the throttle will not fully close & the T.P.S sensor will think as if throttle is slight open & o/p voltage will be different & ECU cuts off IAC valve since throttle is closed the engine doesnt gets enough air for idling & tries to die down, an abnormal state the ecu detects this abnormal condition & reactivates iac to keep engine running so engine is getting air from IAC & through small opening near t.b which is not fully closed causing weired idling.

This is also a common problem observed with people who have enlarged their T.B, if T.P.S is not calibrated properly for fully open/fully close to stock value of TPS volatge w.r.t stock T.B you will notice all kind of weird issues wrt idling & part throttle driving.
Thanks rocam,
thats exactly what I have been trying to explain to veyron1 , leakage via the throttleplate due to carbon buildup is contributing to the air supply additional to what the IACV was providing.
atleast some here agrees
chetanhanda is offline   Reply With Quote
Old 13th September 2007, 20:29   #58
BHPian
 
chetanhanda's Avatar
 
Join Date: Mar 2005
Location: Toronto
Posts: 886
Thanked: 42 Times
Default

Quote:
Originally Posted by veyron1 View Post
I haven't seen Indian cars running MAF except for boosted petrols & diesels, which made me draw to that conclusion. I never said anything about alpha-n; besides, they run off of MAP.
dude dont be so positive abt this..
Skoda = MAF
Cedia = MAF

Quote:
Originally Posted by veyron1 View Post
I've seen the 'Vettes & some other high capacity N.A. engines run MAF, but I figured that was due to the cc factor, which necessitates the measurement of higher flow rates. I do not suppose I've seen a below 2-litre N.A engine running an MAF...or are there? Er....any Indian examples? I'm quite positive the Indian Lancer/Cedia runs MAP.
dude why are you so sure ?
Skoda = MAF
Cedia = MAF
Corsa =MAF
Astra = MAF
Old indian ford escort = Alpha-n (didnt know abt ford escort till Rd karthik from race dynamics told me abt that...)

Quote:
Originally Posted by veyron1 View Post
Beg to differ. I've worked on some cars (example; Santro) where the ECM automatically went into "choke" mode upon detecting a faulty check valve sensor. Engines normally start in "choke" mode causing it to idle at 2-300 RPM above normal, which stabilizes after warming up. Replacing the sensors have rectified the fault- in the cases that I've seen.
dude can you please explain again as Im not able to get it...
whats a check valve sensor ? and how does it make the ecu go in "choke mode" and whats a "choke mode" Im not aware of choke mode as I dont know much about HYundai's ?

Quote:
Originally Posted by veyron1 View Post
I was also not aware that the ECM cuts off IACV snesor i/p's completely once the TB moves off of "0" position.
You wouldn't need a Idlecontrol valve's air supply when you are getting air via the main TB.

Last edited by chetanhanda : 13th September 2007 at 20:30.
chetanhanda is offline   Reply With Quote
Old 13th September 2007, 21:01   #59
BHPian
 
chetanhanda's Avatar
 
Join Date: Mar 2005
Location: Toronto
Posts: 886
Thanked: 42 Times
Default

Quote:
Originally Posted by quicksilver View Post
One thing I noticed though, on the OE headers, the sensor seems to be at a point where the exhaust pipes from all the 4 cylinders merge. On the greddy ones, the O2 sensor is on a single cylinder's exhaust. Theoretically, does this make a difference? I know it feels the same practically now...
Ok, you need to understand that all cylinders dont eactly have same AFR and same temperature. This is different depending on the firing sequence of the cylinders, so if a particular cylinder has a less rich AFR or is more hotter than the corresponding header tube needs to have a sensors.
So in case of EGT and O2 sensors we choose a tube which we feel needs to be monitored, Greddy decided to mount it on the hader tube they felt best suitsthe firing sequence + other parms of the engine.
Thats why never mess with headers unless you know what you doing, very delicate and are very specific to a model to a engine and to the "state of tune" of the engine. Hope that answers ur query.
chetanhanda is offline   Reply With Quote
Old 13th September 2007, 21:57   #60
Distinguished - BHPian
 
Mpower's Avatar
 
Join Date: Mar 2005
Location: Bangalore
Posts: 10,432
Thanked: 1,682 Times
Default

Chetan, are you assuming that all cars have EGR. I'm not so sure that is true.

Also, blowby gases that are trapped into the crankase (PCV) and put into the intake downstream of the TB which suggests they shoudld go right into the engine rather than flow back and clog the TB.
Mpower is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
OHC Suspension Problem EDIT : Solved! KSM-Vtec Technical Stuff 101 13th January 2014 21:08
Linea Diesel: No one is able to solve engine problem EDIT: Now solved ! Travelbug Technical Stuff 35 21st November 2013 23:39
Strange problem with my petrol Swift. EDIT : NOW SOLVED abhaybakshi Technical Stuff 50 11th June 2012 13:01
Vibrations in Baleno at all times (Low varying Idle RPM) rohanmeets Technical Stuff 8 25th February 2008 11:36
Idling problem in my WagonR Lxi..EDIT : Now solved. ramki067 Technical Stuff 8 17th December 2007 11:19


All times are GMT +5.5. The time now is 11:25.

Copyright 2000 - 2017, Team-BHP.com
Proudly powered by E2E Networks