1996 Accord 2.2 Vtec misfire

[ojlane]

I have a UK 1996 Honda Accord 2.2 VTEC with misfire problems and running very lean on fuel.

It is fine for the first 3 minutes from cold then starts misfiring under load (Gearbox engaged rather than disengaged), this occurs when holding a constant speed or lightly accelerating, this happens up to 3500 revs. If I then accelerate hard or decelerate the misfire dissapears. This fault gets progressively worse the hotter the engine gets.

I disconnected the map sensor for a run and the engine ran fine appart from idle revs dropping but as predicted it ran very rich, this to me would rule out ignition problems, is this correct?

I have changed:- HT leads, Spark plugs, Water temperature sensor, Oxygen sensor, MAP sensor and checked EGR valve also all cylinders are running between 14 and 15 BAR.

If anyone can shed any light on this it would be greatly appreciated.

Many thanks, Oliver

 

[pgarner]

dont bother with deaccelaration as fueling is cut on modern cars.

i would have went with the lamba (O2 sensor) in the exhaust but youve already checked it.

 

[obi_waynne]

You've done the obvious. This is a real pain for you. Do you know for sure that the O2 sensor is working properly? I have known new ones to have an issue. Did you replace the sensor and the lead or just the sensor?

Have you had any modifications done to the engine?

What fuel are you using? Are there any air leaks after the AFM?

When it is cold the engine is supplying extra fuel then as it warms up it backs off the fuel delivery. If the lambda detects unburnt fuel (more specifically o2) it will cut the fuelling further causing the engine to run lean.

Ah just thought have you checked the fuel delivery? Is the fuel filter blocked? Are the injectors spraying a nice fine mist or a jet? It would be useful to get the car on a rolling road hooked up to a diagnostic machine and see what is happening live.

 

[ojlane]

Thank you,

I have replaced the O2 sensor with lead and plug about 25cm off another Accord and tried another without plug off a Rover 75 (both from breakers yard).

I have just ordered a brand new one (due Wednesday)

I have not done any modifications and am using standard supermarket fuel, used to use vpower all the time but my wife told me off!!! :-(

I have checked the inlet system for leaks as well but no luck yet,
just hope the new O2 sensor works

Many thanks again

 

[obi_waynne]

URgh Supermarket fuel - not good. Probably not your problem but the car will prefer a higher octane fuel. I wouldn't mind betting the supermarket fuel is only around 94 or 95 RON wheras Vpower is around 100 Ron. It would be worth trying it with a tank or at least half a tank of Vpower and see if it runs better.

Another thing to try is some redex fuel cleaner - it is certainly worth a go.

Take out the fuel filter and see if there is a wax build up. Its a long shot but you've tried so many of the other options.

 

[prevtec]

hi mate,
my girls dad had a similar problem, ended up being a distributor,1 of the lugs where the leads go was on the way out. dying, #!#!#!#!ed

because you got leads,new sensor its more than likley somthing like the distributor,not a 100% sure though
does the car drive but lacks its full power??

 

[ojlane]

The car goes as well as ever when I put my foot down, it`s only when I`m gentle that I get problems (Holding speed and light acceleration) my wife is the main driver of this car now and she has got a VERY light right foot!!!

I fitted the new O2 sensor today with no change at all scheduled for tomorrow is a new fuel filter and injector dismantling and cleaning, if that does not work I will order a distributor.

At this rate I may have been better dropping in a recon engine!!

 

[obi_waynne]

Have you had it on a diagnostic? It can save a lot of money paying a garage with the right setup to diagnose a fault like this.

Keep us posted - it will be helpful for others with similar faults.

 

[pgarner]

a 96 might not have diagnostic capability as thats what i was going to say 1st.
other thoughts are idle valve or throttle cable

 

[jdmlude]

hi my h22 had this problem just before i brought it and it was the dizzy cap and arm replaced that fixed it

 

[ojlane]

Thinking this may be my problem, a cracked injector!

I will get some more and try, fingers crossed!!!

 

[obi_waynne]

Well spotted. My fingers are crossed too.

(This thread is in our new Accord forum now!)

 

[jdmlude]

well sourced as ur knock sensor would of stopped u from noticeing that well done fingers crossed

 

[ojlane]

Today, replaced fuel filter, injectors, distributor cap plus rotor with no change!!!

 

[pgarner]

ECU might need reflashed, its about the only thin that youve not replaced

 

[obi_waynne]

Defniately get a diagnostic done on the car. Plus stick a tank of super unleaded in it.

 

[ojlane]

I have EGR cleaning planned for tomorrow / Tuesday, Throttle body for Wednesday and diagnostic booked with Honda on Thursday (Booked ages ago but this was first appointment available) we will see......

 

[obi_waynne]

Keep us posted. You've pretty much paid for a new engine all ready with all those additonal parts. I feel for you - these faults are so hard to track down.

 

[ojlane]

Fixed at last!!!!!! :bigsmile: It was the EGR system, Totally blocked to three of the cylinders!!!

Thanks to everybody for all your help, I have learned a lot in the last two weeks.

Is it worth cleaning the EGR system on the Accord and the Legend (RL) at regular intervals anyway???

 

[pgarner]

Didnt think the EGR system on petrols got that bad, i know that its supposed to be cleaned out regulary on a diesel engine

 

[obi_waynne]

Well done. Just keep all those old bits - they might come in handy some day.

I bet it feels a LOT better now.

 

[ojlane]

The one arrowed below had the only spark plug with correct coloured deposits, maybe that should have pointed to this problem

 

[nastyper]

Fixed at last!!!!!! :bigsmile: It was the EGR system, Totally blocked to three of the cylinders!!!

Thanks to everybody for all your help, I have learned a lot in the last two weeks.

Is it worth cleaning the EGR system on the Accord and the Legend (RL) at regular intervals anyway???

Egr gets blocked on the Accord type Rs as well but doesnt cause the misfire, just puts eml light on. I had a misfire under load on my ATR i changed the dizzy cap, rotor arm and ignition coil which sorted it out. Generally they start misfiring if the valve clearances doing. Glad you sorted your problem but if it still does after that then get your VCs done and maybe get a new ignition coil.