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Honda Jazz Forums => Honda Jazz Mk1 2002-2008 => Topic started by: ansys on August 12, 2017, 04:28:35 AM

Title: 2002 Honda Fit acceleration issues
Post by: ansys on August 12, 2017, 04:28:35 AM
Hi everyone,
I've got a JDM 2002 Honda Fit in New Zealand.  I recently replaced all 8 coil packs a few months back to fix a previous engine misfire (but didn't replace spark plugs).  Now, it seems I'm having issues while accelerating.  The engine seems to be down on power until about 50km/h or so and then you can feel the car take off (at least relative to what that little engine can do...).  Along the way you can feel periods of a slight shudder, or grinding? or rough running when accelerating from a stop, then again from around 20-30km/h, then again around 40-45km/h  or something along those lines.  The roughness kind of comes and goes as you accelerate, though it is always lacking power until it seems to "break free" somewhere between 50 and 60km/h. 

Shortly after the coil packs were replaced, I noticed this slight shudder for a second or two when accelerating from a stop, but it was very slight and only from when stopped.  Now it seems to have gotten significantly worse all of a sudden (as described above). 

Probably unrelated, I had to jumpstart the car a couple weeks ago.  It had been running fine after that until now.  I have already done the ECU/PCM reset procedure and it didn't seem to make a difference.

Also, problem may seem to be worse after the engine has warmed up?? though not positive on that one.

I've got a couple theories, but am keen to hear what everyone here thinks.  Thanks in advance for your help!
Title: Re: 2002 Honda Fit acceleration issues
Post by: Jocko on August 12, 2017, 08:47:54 AM
Welcome. Can I ask why you didn't replace the plugs while you had the coil packs off? Also the ECU/PCM reset procedure. My 2006 doesn't need any resets, as far as I'm aware. I have needed one jump start, then fitted a new battery, and needed to do nothing. Perhaps the JDM Fit is different from the UK Jazz.
Title: Re: 2002 Honda Fit acceleration issues
Post by: sparky Paul on August 12, 2017, 09:20:56 AM
Fuel mix is leaner when the engine is up to temperature. Have you checked the condition of the plugs, and re-gapped or replaced as necessary? That would be my first port of call for any misfire, the colour of the plugs can give you other clues too.

When you replaced the coil packs, did you replace them with genuine, or cheap aftermarket ones? Faulty coil packs can also show up when hot.
Title: Re: 2002 Honda Fit acceleration issues
Post by: culzean on August 12, 2017, 09:43:10 AM
Replacing spark plugs is the cheap enough,  and as Jocko says,  if you went to the trouble of removing coil packs it would not take long to replace plugs.

ECU reset just removes its learned parameters and takes it back to base settings,  I have never had to do this (used to remove power from ECU when I changed a battery,  but that was the only time,  haven't even done that since I made up a 20 metre double cigarette lighter plug cable and now use another car to donate power while I change the battery).  What I remember is that the car did run a bit rougher for a few days after power had been removed from ECU,  but it soon got back to 'normal'.
Title: Re: 2002 Honda Fit acceleration issues
Post by: ansys on August 13, 2017, 04:57:12 AM
all 8 spark plugs have now been replaced.  Didn't really make a difference. 

The ECU/PCM reset is more precautionary than anything.  From what I've been reading, it isn't necessary most of the time.  I just did it in case the shuddering I was feeling was CVT related.

I've tried to clean out the EGR valve as best I could, and that doesn't seem to have made a difference.

The car runs perfectly when it is cold, but shortly after the cold engine light goes out, the engine starts misbehaving... sputtering, etc. under load when I try to accelerate.

Any other thoughts? I'm banging my head on this one
Title: Re: 2002 Honda Fit acceleration issues
Post by: culzean on August 13, 2017, 09:43:25 AM
[quote author=ansys link=topic=9391.msg50810#msg50810 date=1502596632
The car runs perfectly when it is cold, but shortly after the cold engine light goes out, the engine starts misbehaving... sputtering, etc. under load when I try to accelerate.
[/quote]

As SparkyP already remarked, the mixture is richer when cold (more fuel squirted in) so if it runs OK until temperature light goes out it may be mixture related and it is running too lean when warmed up.  Try an injector cleaner (STP, Redex etc.) they are cheap enough.  Otherwise one of the airflow sensors may be playing up.
Title: Re: 2002 Honda Fit acceleration issues
Post by: Jocko on August 13, 2017, 09:55:41 AM
Slightly off topic, but where did you find information on the ECU/PCM reset, and how do you do it? Cannot find anything in my owners or Haynes manual.
Title: Re: 2002 Honda Fit acceleration issues
Post by: ansys on August 13, 2017, 11:59:46 AM
so, I haven't done any work to the car since the last post, but a couple drives later, and (knock on wood), it seems a bit better, though not completely.  Previous test drives were quick down the the road and back sort of thing.  Maybe it just took a little longer for some things to take effect??? 
I do notice some audible knocking while trying to accelerate moderately hard around 60-80km though...  It is somewhat random (not rhythmic with the engine), though fairly loud as I can hear it clearly with the windows up and radio off.

probably unrelated, but the day before the problems showed up, the car was fueled up at a gas station different from normal, though still from the same brand/chain as normal (Caltex).  There was maybe about 1/4 tank left before filling it up.  Could I have gotten some unlucky dodgy gas from this station?

I'm kind of skeptical when it comes to any of these so called miracle additives.  Have you had any good luck before with injector cleaners?  Aren't they more of a preventative maintenance type thing as opposed to trying to fix a problem?  As you say though, they are relatively cheap and it can't hurt.

As for the ECU/PCM reset, I think it's almost never required, but I found this thread to be quite helpful for learning the process.  I've done both versions:
http://www.ozhonda.com/forum/showthread.php?43307-CVT-recalibration-procedure-what-result-did-you-get (http://www.ozhonda.com/forum/showthread.php?43307-CVT-recalibration-procedure-what-result-did-you-get)
Title: Re: 2002 Honda Fit acceleration issues
Post by: Jocko on August 13, 2017, 12:41:00 PM
As for the ECU/PCM reset, I think it's almost never required, but I found this thread to be quite helpful for learning the process.

I see. It is purely a CVT issue. That is why I have never had anything to do with it. My Jazz is manual.
Title: Re: 2002 Honda Fit acceleration issues
Post by: guest1372 on August 13, 2017, 03:02:18 PM
There is 0.1% possibility that it is a wiring issue but that would trigger a fault code.  On some electronic throttle cars the wiring between the ECU and the throttle body has a tight wire in a 90° conduit junction, this bend breaks the internal copper leading to an intermittent throttle response in certain circumstances.  Sometimes general unrelated maintenance just moves the wire back into a position that maintains it's continuity.  The fault code may not trigger the check engine light but should be logged as something like 'throttle body high voltage' or low voltage or similar. 

The symptoms are a general disconnect between pedal position and rpm, not rough or lumpy running although if the wire break is only slightly intermittent it may be hard to spot.
--
TG
Title: Re: 2002 Honda Fit acceleration issues
Post by: ansys on August 14, 2017, 09:52:23 AM
I used an OBD reader to try and pull fault codes from the car, and it came up empty... no fault codes.

I'm really running out of ideas... Would there be any reason why a CVT would run fine when the engine is cold, but give issues once the engine warmed up?  I can't think of any, but I'm running out of things to check on the engine side unless I just go blindly replacing things
Title: Re: 2002 Honda Fit acceleration issues
Post by: ansys on August 16, 2017, 09:29:12 PM
another update...
I reduced the spark plug gap to about 0.032" - 0.035" as recommended in some other posts, and that seems to have smoothed out the ride (for now...)

I imagine this 'fix' will only be temporary.  What should I be looking at to fix it more long term?  New coil packs?  adjust the valves??
Title: Re: 2002 Honda Fit acceleration issues
Post by: ansys on August 20, 2017, 10:21:43 PM
One more confusing anecdote.  It may just be in my head, but it seems the car runs more smoothly in the mornings and evenings than in the middle of the day.  Also, yesterday I took the car out for about a 20 minute drive a little before sunset.  It wasn't performing so smoothly.  It was parked for about 20-30 minutes.  In that time, there was a short and sudden heavy rainfall.  The storm passed and we drove back for another 20 minute drive.  By this time the sun had set and it was 'dusk'.  On the drive back though, the car behaved noticeably better.  Could the humidity in the air have anything to do with it?  Or did the rain somehow get anywhere?  Colder air temperatures?  I'm in a fairly humid environment (humidity levels increase significanly when the sun is down) and at the moment temperatures during a day will range from 9C to 16C.
It all seems far fetched to me though....
Title: Re: 2002 Honda Fit acceleration issues
Post by: ansys on August 21, 2017, 01:07:59 AM
I’m using the Torque Lite app on my phone with the OBDII. There’s some graphs it says I can pick up like “O2 Sensor1 Equivalence Ratio”, “O2 Volts Bank 1 sensor 1” (and 4 sensors with bank1 and 4 sensors with bank 2), and “mass air flow rate”. It also has something called a “Fuel / Air status widget”. Is there something I can look out for with these outputs that may be an indicator of O2 sensors or Mass Flow sensors operating incorrectly but not bad enough to throw a fault code? Thanks again!
Title: Re: 2002 Honda Fit acceleration issues
Post by: MikeG1944 on August 21, 2017, 09:40:51 AM
Could the humidity in the air have anything to do with it?  Or did the rain somehow get anywhere?  Colder air temperatures?  I'm in a fairly humid environment (humidity levels increase significanly when the sun is down) and at the moment temperatures during a day will range from 9C to 16C.
It all seems far fetched to me though....

It's always been known since the invention of the combustion engine that they run a little better with humid air, although the exact reason escapes me. In fact I believe there was some device brought out which injected a little moisture into the air intake many years ago. Perhaps there is a scientific reason, but always remember mechanics telling me this in days gone by.
Mike.
Title: Re: 2002 Honda Fit acceleration issues
Post by: culzean on August 21, 2017, 10:29:59 AM
Could the humidity in the air have anything to do with it?  Or did the rain somehow get anywhere?  Colder air temperatures?  I'm in a fairly humid environment (humidity levels increase significanly when the sun is down) and at the moment temperatures during a day will range from 9C to 16C.
It all seems far fetched to me though....

It's always been known since the invention of the combustion engine that they run a little better with humid air, although the exact reason escapes me. In fact I believe there was some device brought out which injected a little moisture into the air intake many years ago. Perhaps there is a scientific reason, but always remember mechanics telling me this in days gone by.
Mike.

Anyone who has ever had a 2 stroke motorbike knows they run much better in humid conditions as the water in the air makes the charge more dense and flashes to steam when charge is ignited.  There was even talk of 'water injection' (in aerosol form,  not a hose pipe) in IC engines to improve efficiency.  when car makers are testing their cars on rolling roads they carefully ensured that the humidity and temperature in the 'laboratory' was right for maximum benefit (they also disconnected aircon, alternator and any other load on the engine) - and they never thought it was 'cheating'.

http://spectrum.ieee.org/cars-that-think/transportation/efficiency/squirts-of-water-can-boost-engine-performance-fuel-economy-by-13

the linked article suggests that some of the fuel is used to cool the engine rather than produce power,  so if you can cool the engine combustion with water it can increase power and improve mpg.
Title: Re: 2002 Honda Fit acceleration issues
Post by: Jocko on August 21, 2017, 10:30:38 AM
Water is H20, both of which are the ingredients of combustion. I believe it increases the density of the charge. It also helps to cool the charge by latent heat of evaporation and the power from a given "combustion" is dependant on the change of temperature as it burns. Therefore the colder the mixture is before the ignition starts the greater the change when it reaches combustion temperature. If I remember my Ricardo correctly.
Title: Re: 2002 Honda Fit acceleration issues
Post by: MikeG1944 on August 21, 2017, 10:38:04 AM
Thanks Jocko; That makes sense. I thought there must be some scientific explanation.  :)
Title: Re: 2002 Honda Fit acceleration issues
Post by: ansys on August 21, 2017, 12:24:18 PM
hmm. good stuff on all the combustion theory!

a couple other things I've tried to take a look at so far with my OBDII reader (using the Torque Light app)...
tried to watch the readings for the O2 sensor, and they seem alright.  The graph display shows the reading fluctuating between -0.1 to 0.7V or so, but the dial indicator shows it between 0.1V - 0.8V.  I imagine the graph reading negative might be a problem with the app??  Also, when the engine is being revved, the frequency of the signal wave seems correct.  At idle it is quite slow, but I assume that's not an issue.

Those readings were on O2 sensor 1 bank 1.  All other O2 sensors/banks were not giving any signal.  I was a little surprised because I thought there would be an O2 sensor after the catalytic converter, but the OBDII wasn't picking it up.  I had a very quick look under the car to see if I could see the sensor, but I couldn't find one... do early JDM fits only have the one O2 sensor?  Admittedly my search for the 2nd one was pretty brief.


I checked the vacuum readings the OBDII was giving back, and everything checked out normal as per these references:
http://www.gregsengine.com/using-a-vacuum-gauge.html
http://www.onallcylinders.com/2015/05/08/quick-tech-how-to-read-a-vacuum-gauge-to-pinpoint-engine-problems/


any suggestions on what to investigate or pursue next???  Car runs pretty well when the sun is down, but when the sun is up it give some hesitation/stutter issues. 

Thanks again for all the help so far!

Title: Re: 2002 Honda Fit acceleration issues
Post by: Jocko on August 21, 2017, 01:47:27 PM
There are two heater Lambda (O2)sensors on the exhaust. One ahead of the catalytic converter and one downstream from it. Shown here at either end of the cat.

(http://www.hondafitjazz.com/manual/A00/PNG/SAA2EK0A18400025601KBAD01.PNG)