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UPDATE

Just to let you know a great guy called Phil at K&P Auto Services, Tonypandy, South Wales has had the car since Thursday 6th October and has been testing it since. He managed to pump air into the engine without the MAP sensor connected and it stopped misfiring when rev'd between 2.5 to 3k rpm so it shows that spark plugs, coils, ignition etc were all OK. This 'tricked' the car in a way to simulate air intake. We have found that the wiring runs from the MAP sensor to the Crank sensor which is directly below the coolant pipes at the front of the engine, the same coolant pipes that were removed to drain the coolant when the problem started. My initial thought was that maybe the coolant had allowed moisture through to the connector for crank sensor which may have affected the PGM-FI (Honda's name for the fuel system which uses multiple sensors and data to dictate fuel mix). As Phil has said with him pumping air into the engine it may not mean it is the MAP sensor it may mean that it is just covering up or 'tricking' the ECU to get fuel mix right at any point of the PGM- FI. Really complicated stuff.

So, the plan and next move is a new MAP sensor (Honda part £270-300 from Honda but managed to get one from Tegiwa for £45) and new Blueprint Crank Sensor (£60 inc VAT) which will be installed tomorrow.

If it works I will update.
 

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Discussion Starter · #23 ·
Oh well, it seems you have (hopefully) at least found something! Great news, let us know how it goes!

I'm still stuck with mine, checked the oil filter and the V-tec oil control valve's screen for debris (as per a tech recommendation), but it was clean enough. Error still occurs. Does your car flashed the error while at idle as well?
 

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What Phil did was remove the MAP sensor and place his finger over the MAP sensor hole and then pumped air into engine and this stopped misfire between 2500-3000rpm where the problem lies. I am hopeful that a new MAP sensor may work as this was the missing link when he was testing but nothing is guaranteed. Will definitely update this thread.

If I rev to 2500-3000rpm the car will misfire and the EML will flash and then VSA will kick in due to misfire. The EML will flash if you continue to rev for a long time. Sometimes the EML will flash for a while and then go off completely. My understanding is that when that happens it is because it is registering a temporary code. When the code is permanent the EML stays on without flashing and this stays until codes are cleared.

What Phil has confirmed as well is that cylinders 1 and 4 are the two affected when it misfires. 2 and 3 remain fine. This can be seen on live data.

This is definitely a fuel mixture issue.

SvilenDi - if you forward an email address I can send you a link to a Honda Service Manual which is viewable only in Internet Explorer and contains useful technical data and install instructions, it also explains the PGM-FI (Honda fuel injection system) and the sensors involved, there are lots of them! It may help you.

I feel your pain.
 

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based on the random misfire and your mileage, have you considered the flywheel? iirc a failing dual-mass flywheel typically cause a misfire fault.

a quick generic search sugests that it does idle poorly with a faulty flywheel which you havent mentioned.

It's worth saying i have no experience with 8th gen's...
 

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Car was unable to be fixed.

The general consensus was that it seemed like an ECU data problem whereby the data returning from sensors was providing a fuel mixture that was too rich for the engine and in turn would cause misfire. New ECU would have cost more than car.

I had to stop at that and have got rid of my 8th gen Civic. I was really disappointed and never expected this to happen with a Honda petrol engine. I still have a 9th gen Civic with exact same engine (slight differences in engine bay) and have lost faith totally.

I think the issue is rare but this is no consolation to me or Svilen Di. Sorry I couldn't get to the bottom of it.

Hope you guys have better luck.
 

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Discussion Starter · #29 ·
Sorry to hear that, dohowells28. From all of the tests I've been able to perform so far - ECU was not the root cause of the issue - I replaced from another car but it was still misfiring with a new ECU. Have you guys tried to check up the fuel pump and the fuel pump screen? I'm just now wondering if we're losing fuel pressure while sitting at those rpms...
Not losing hope, I'm gonna fix this sooner or later...just don't have the time at the moment.
 

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I put a brand new fuel filter in but didnt change fuel pump or the other metal thing at the base of the filter (both expensive) they just came off old one and into new one.

All appeared ok in the tank. Fuel was tested and was all good.

I will return here to ch ck if you have fixed yours, out of interest.

I had to ged rid because I have two young children and couldn't cope without car that I could rely on.
 

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Discussion Starter · #31 ·
I perfectly understand how you feel. Will post here as soon as I have any news. Rocker arm with the whole cylinder head will be switched soon from another car...hopefully this will fix it.
 

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Have you had the fuel pressures tested?

If it was 1/2 cylinders I'd say swap sparks and injectors around but if it's affecting all 4 then it may be supply as a whole. Also are you fully clearing the codes after each diagnostic? I know on some manufacturers the ECU needs a proper scanner to clear, not sure if Honda just needs battery unplugged. It's good practice just in case the fault is fixed but the ECU still has codes and still throws the same error.
 

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The i-vtec opertion on this car happens from 1000 rpm to 3500 rpm.
I have a vtec led connected to the vtec solenoid valve and can see when it's on (eco mode) and when it's off (normal 16v mode)...
So, with proper conditions (1000-3500rpm, not stationary, warm engine, 3th 4th 5th and 6th gear, low throttle, etc...) the i-vtec engages...
But it has an interval rpm at vtec max rpm cut off, meaning: If I'm going with it on, and rpm is rising slowly the i-vtec turns off at 3500rpm... But if I'am coming from let's say 4000rpm and easing off throttle, it wont engage at 3500rpms because it's the max it will go, but at 3200-3300rpms, then off at 3500rpms...

What I want to say with all these is that going at 3000-3300 rpms and stay there with light throttle will engage i-vtec for sure and a few rpm above will disengage vtec...
Your problem happens on that rpm space, and ecu is reading all the sensors to engage/disengage vtec and maby your cell light come on because:
- one of those sensors give bad data;
- engine can't go phisically in/out of vtec;

so check: the wires that go to vtec solenoid, check vtec solenoid, check speed sensor cause vtec does'nt work stationary, check the 2 coolant temp sensor, check tps (throtle position sensor) a bad tps it can give floating values, check oil pressure too, can't remember anything else related to vtec engagement but maby your mechanic can...

I'm no mechanic, just trying to help.
Let us know when you figure it out.
 

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Discussion Starter · #37 ·
Quick update...
Rocker arm wasn't the issue. Car is misfiring with a pack from another car. My mechanic suggested to swap the block with one from an R20 engine , what do you guys think about it? Is it applicable, will it fit properly?
 

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Discussion Starter · #39 ·
I meant the head, sorry... my mistake. Compression test has been made as well, no errors found. I'm really close to give up since we tried pretty much everything.
 
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