Engine dead spot right after a cold start

ashish_me2 · 27th April 2015, 10:14

Hi All,

I have a Honda City I-VTEC (MT) which has completed 35.5K of regular running. Serviced regularly at the ASC. For the last 4 months I'm observing a strange behaviour with engine and would appreciate any insights as the ASC technicians are clueless -

When the engine is started first time in the morning and if I start driving right away with the engine temp. blue light still on, everything is as expected till I switch from 3rd to 4th gear. At a speed of 40 Kmph, a shift from 3-4 gear leads to a slump in the engine RPM as if the engine was suddenly starved of fuel. It then picks up again but the behavior is consistent for the last 4 months.

The natural suspect was fuel quality in Hyderabad so I switched to Shell and other reliable outlets without any change. The ASC also ran a full diagnostic on the system and did a reset of the ECU. That too did not bring any change to the behavior. The air filter has been replaced too.

Any insights about what to look at or how to troubleshoot will be greatly appreciated as I really need to get this resolved.

-Thanks,
Ashish.

Jaggu · 27th April 2015, 10:37

Have you tried checking the throttle body, and idle system? Also do check if the injectors and fueling system for any minor blocks. Starvation seems to be a fueling issue hence suggesting these.

rakesh_r · 27th April 2015, 11:28

What i can suggest-
1-Check fuel pump and fuel filter.
2-Injectors.
3-Fuel tank for debris and water.

Looks like a typical fuel starvation issue.

MrIncredible · 27th April 2015, 11:33

Check the Fuel Pump,Fuel Filter and Injectors.

pramodkumar · 27th April 2015, 11:54

Guys this happens during start and cold engine, The OP does not confirm of this behaviour when the engine reaches temperature. its the MAF sensor which might be causing the issue. Ashish can you replicate the issue? does it happen only during a certain conditions? If yes then please take the car to the A S S, ask them to swap the MAF sensor with a working one and try to replicate the issue. If it is gone then you know what is the culprit.

Pramod

ashish_me2 · 27th April 2015, 12:06

Thanks for the responses. Can you point me to some good DIY article and a MAF cleaner that can do the job?

S5157 · 27th April 2015, 13:33

See this DIY article on Team-bhp on MAF sensor cleaning

http://www.team-bhp.com/forum/techni...-rs-120-a.html

Shreyans_Jain · 27th April 2015, 13:45

My Jazz displays identical behavior, despite injectors and throttle body being cleaned regularly. I find that using System G fuel additive helps. But the biggest part is played by the fuel itself. There are times when I get genuinely good fuel and it shows in the drive: pick-up improves and this flat-spot issue subsides on its own.

The important thing to note is that these iVTECs are tuned for 91 octane petrol (there is a bold sticker on the inside of the fuel tank lid of my car saying the same), hence are quite sensitive to substandard petrol which we, unfortunately, often have to make do with, even in Delhi-NCR.

dhanushs · 28th April 2015, 17:51

If the problem is only during cold starts then its the O2 sensor.

If you plugin an OBD, you'll get a P0141 or similar error.

kiku007 · 28th April 2015, 17:58

I've had this problem in the Fiesta petrol and it was due to faulty O2 sensor. The Fault code will tell this.

27th April 2015, 10:14	#1
ashish_me2 Newbie Join Date: Dec 2007 Location: Hyderabad Posts: 16 Thanked: 0 Times	Engine dead spot right after a cold start Hi All, I have a Honda City I-VTEC (MT) which has completed 35.5K of regular running. Serviced regularly at the ASC. For the last 4 months I'm observing a strange behaviour with engine and would appreciate any insights as the ASC technicians are clueless - When the engine is started first time in the morning and if I start driving right away with the engine temp. blue light still on, everything is as expected till I switch from 3rd to 4th gear. At a speed of 40 Kmph, a shift from 3-4 gear leads to a slump in the engine RPM as if the engine was suddenly starved of fuel. It then picks up again but the behavior is consistent for the last 4 months. The natural suspect was fuel quality in Hyderabad so I switched to Shell and other reliable outlets without any change. The ASC also ran a full diagnostic on the system and did a reset of the ECU. That too did not bring any change to the behavior. The air filter has been replaced too. Any insights about what to look at or how to troubleshoot will be greatly appreciated as I really need to get this resolved. -Thanks, Ashish.
	() Thanks

27th April 2015, 10:37	#2
Jaggu Team-BHP Support Join Date: May 2004 Location: Bangalore Posts: 20,215 Thanked: 15,907 Times	re: Engine dead spot right after a cold start Have you tried checking the throttle body, and idle system? Also do check if the injectors and fueling system for any minor blocks. Starvation seems to be a fueling issue hence suggesting these.
	(1) Thanks

27th April 2015, 11:28	#3
rakesh_r Senior - BHPian Join Date: Nov 2009 Location: Pune Posts: 1,928 Thanked: 2,834 Times	re: Engine dead spot right after a cold start What i can suggest- 1-Check fuel pump and fuel filter. 2-Injectors. 3-Fuel tank for debris and water. Looks like a typical fuel starvation issue.
	(1) Thanks

27th April 2015, 11:33	#4
MrIncredible BHPian Join Date: Apr 2015 Location: Bangalore,Paris Posts: 28 Thanked: 5 Times	re: Engine dead spot right after a cold start Check the Fuel Pump,Fuel Filter and Injectors.
	() Thanks

27th April 2015, 11:54	#5
pramodkumar Senior - BHPian Join Date: Mar 2006 Location: Gods own country Posts: 2,302 Thanked: 2,208 Times View My Garage	re: Engine dead spot right after a cold start Guys this happens during start and cold engine, The OP does not confirm of this behaviour when the engine reaches temperature. its the MAF sensor which might be causing the issue. Ashish can you replicate the issue? does it happen only during a certain conditions? If yes then please take the car to the A S S, ask them to swap the MAF sensor with a working one and try to replicate the issue. If it is gone then you know what is the culprit. Pramod
	(2) Thanks

27th April 2015, 12:06	#6
ashish_me2 Newbie Join Date: Dec 2007 Location: Hyderabad Posts: 16 Thanked: 0 Times	re: Engine dead spot right after a cold start Thanks for the responses. Can you point me to some good DIY article and a MAF cleaner that can do the job?
	() Thanks

27th April 2015, 13:33	#7
S5157 BHPian Join Date: Sep 2009 Location: Muvattupuzha, K Posts: 305 Thanked: 191 Times	Re: Engine dead spot right after a cold start See this DIY article on Team-bhp on MAF sensor cleaning http://www.team-bhp.com/forum/techni...-rs-120-a.html
	() Thanks

27th April 2015, 13:45	#8
Shreyans_Jain Distinguished - BHPian Join Date: Nov 2013 Location: HR51/HR29/HR26 Posts: 2,758 Thanked: 21,241 Times	Re: Engine dead spot right after a cold start My Jazz displays identical behavior, despite injectors and throttle body being cleaned regularly. I find that using System G fuel additive helps. But the biggest part is played by the fuel itself. There are times when I get genuinely good fuel and it shows in the drive: pick-up improves and this flat-spot issue subsides on its own. The important thing to note is that these iVTECs are tuned for 91 octane petrol (there is a bold sticker on the inside of the fuel tank lid of my car saying the same), hence are quite sensitive to substandard petrol which we, unfortunately, often have to make do with, even in Delhi-NCR.
	() Thanks

28th April 2015, 17:51	#9
dhanushs Distinguished - BHPian Join Date: Oct 2009 Location: Chennai Posts: 4,282 Thanked: 10,180 Times	Re: Engine dead spot right after a cold start If the problem is only during cold starts then its the O2 sensor. If you plugin an OBD, you'll get a P0141 or similar error.
	(1) Thanks

28th April 2015, 17:58	#10
kiku007 Distinguished - BHPian Join Date: Apr 2005 Location: AU Posts: 2,322 Thanked: 7,193 Times	Re: Engine dead spot right after a cold start I've had this problem in the Fiesta petrol and it was due to faulty O2 sensor. The Fault code will tell this.
	() Thanks