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Jumpy EP3 and idle problems

Jak

Jak

Messages
31
Hi guys,

For about 2 months, my ep3 has been quite aggressively jumpy with light revs (mainly 2nd). At the time my EML was on and a diagnostic tool said it was running too rich. So I replaced the post cat sensor as that's more likely to fail due to heat exposure. I would also like to mention that the EML was very temperamental turning on or off every other day - sometimes even a week at a time... anyway, it was still quite jumpy and I read up on the idle control valve being a common problem, so took off the induction, opened the throttle body and sprayed some brake cleaner in there.

This cured the problem for about a month up until now with very little jumpyness. I would like to mention the EML came back on with the same error as before about a week ago, so I changed the pre-cat sensor the saturday just gone and next day the car went back to its old jumpy self.

So what I'm asking is: would I benefit from stripping down the throttle body and giving the idle control valve a thorough clean? If the problem still persists could it be the TPS?

Oh, and at the latest service carried out start of Febuary the guy mentioned a small hole in my back box. This couldn't cause the hesitation and jumpyness could it...? Starting to worry now because last night in VTEC in 3rd gear it started doing it which is never has done before. I'm going to properly clean the idle control valve tomorrow regardless.

Also, with regards to the idle (I'm sure this is all linked) as it happened when the pre cat sensor was fitted this weekend too.
It is VERY temperamental with idle when warm sometimes being the normal 850rpm. But sometimes it will be 750 standing still when warm and 500 coasting when warm (before I sprayed the TB before it would stall as I was coming to a stop sometimes)
When cold it is between 1200 and 1500 but soon drops to around 1100 then it starts spazzing out when warm.

Thanks in advance :)

PS: I'm aware there are similar threads, but with the random EML complications cropping up on mine it's not entirely similar to other peoples.
 
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Was it a genuine secondary sensor you used? Some cheaper ones have been known to go after a very short period of time. That would explain the lumpyness under normal driving and EML, but that come is usually high voltage bank 2 etc.

Erratic tick over does sound like the ICV though.

Sounds like you have a combination of faults.
 
Does the NGK/NTK sensors count as genuine? I know they make good quality parts, so wasn't too worried and the EML went out both times right after installation.

Yeah I'm really hoping it's the ICV as that just takes some time and not money thankfully. Gonna give it a thorough clean tomorrow and will let you know how I get on. Any ideas from there if I have no luck?
 
Yeah, they should be spot on really.

If the ICV clean doesn't help, I'm sure it will, then you'll need to check the calibration on the TPS, several threads on it. If it's out and you can't set it up properly, or it keeps fluctuating then it's looking like a new one. Shouldn't really throw a fuelling code though.

Also worth checking your throttle cable isn't slack on idle. Shouldn't be opening the throttle plate, but should be reasonably snug.
 
Oh balls, the EML came back on this morning on the way to work, just plugged in the diagnostic tool and it says its too rich again! (bank 1) Can there be anything else besides the cat sensors playing up that can cause this? Just about to do the ICV. Wish me luck lol
 
What fault code are you getting?

Tried swapping the plugs and or injectors to another cylinder to see if the problem follows the swap?
 
Done the clean and took the car for a spin, it's way better! (for now lol) no jumpyness, idle is 1000 when coasting and 800/850 stood still when warm. The amount of gunk in the ICV was shocking! EML is still on so will have to look into that at the weekend.

Cheers for all your advise Loxy, you're the Yoda of Type R's! Haha :)
 
Hi Jak,

I had this issue with my EP3. I had been using super unleaded solid for 3 weeks and then my EML had come on. I too got the PO172 (Too rich at bank 1) code stored.
At the time I thought the V-power nitro was to rich for my standard ECU to handle.(Am I right in saying Loxy that it should just adapt to the fuel?) Anyway this went on for a while and Honda replaced my primary O2 sensor.

I then went back to reg 95 fuel. To cut a long story short.. lol It happened with using reg unleaded when i filled my tank up. It turns out I had an emissions sensor with an intermittant fault and only would happen at certain times. Always came back with the same fueling error code.

So Honda took a look and on their system came up as a possible fault with my MAP sensor, EVAP Purge valve or secondary O2 lamda sensor. I thought stuff it and got all 3 replaced. My EP3 is 9 years old and only had 39K on her when I bought her. So the sensors done a good innings.

I mean it might not be any of these things for you but just wanted to give you a heads up on my experience and help you where I can.

My Type R runs much smoother now and I fill up with SUL just now and again to clean my engine through.

Sorry for the long reply. :)

Hope this helps. And you get the issue fixed soon Jak. Loxy can you correct me please if I have missed something :)

All the best

Scottish
 
It'd put my money on it being a sensor issue.

V-power or not, it's throwing or thinks it's throwing too much fuel in.

The only adjustment the ECU will made for V-power on a standard map is if it detects knock, which it is less likely to do with V-power. It won't change the timing, fuelling or cam advance otherwise.
 
Cheers for the wise words Scottish :) After cleaning the ICV I plugged in the diagnostic and reset the ecu and it hasn't come on since (touch wood). It's a LOT less jumpy now but still feels like there's a loss of power especially in the low rev range however the delivery is a lot smoother. She's touching 99k at the moment so if the weather's decent tomorrow morning I'm gonna do the valve clearances first thing.

Every other tank I put super unleaded in (BP ultimate most of the time) so I'm not sure if this can mess around with the ecu (any light on this Loxy?)

Sooo if this doesn't solve things then it's likely to be narrowed down to the MAP sensor or EVAP purge valve? Just looked on ebay and the MAP sensor is £154 for a blueprint one; is that a good price? And I have never heard of an EVAP purge valve before, any idea where to get a new one and how much they cost?

Cheers guys :)
 
I got Honda OEM sensors. Bit expensive through dealership but it's my main car so thought stuff it. Evap purge valve price I have on my work sheet from Honda. But you will find it cheaper elsewhere I'm sure.

As for the SUL that's fine it's better fuel for the car. Mine is on standard map and I see better mpg and throttle response with SUL. But I have decided to go KPro4 to make use of it fully.

do you use an oil based air filter? Or do you run an induction kit? You may need to clean the MAF too. Mass air flow sensor.

i am sure Loxy will keep me right on my advice to you. I'm still learning about these cars and this forum and the experienced owners here been a great resource of advice..
 
EP3 doesn't have a MAF, only a MAP. It's before the days that emissions regulations dictated that it needed one.
 
MAF is a more complicated way of doing things combined with the dbw throttle body. It's an aid for the ECU to calculate a more environmentally friendly way of controlling the fuelling and throttle plate position based on the engine load and environmental conditions.

A throttle cable just opens the throttle and the ECU responds with fuel, the DBW system calculates whether it can/should before opening the throttle.
 
Thanks Loxy for explaining that. :) The EP3 is my first Honda and hot hatch. Driven Nissans before. Though my Dad had a Seat Ibiza GTi Cupra sport 16v. That was fun to drive. But always been a Japanese car man.
The only gripe I have with the EP3 is the emission sensors and the paint they used on it. But nothing is perfect and the car is still fun and awesome to drive. :)
 
Right, did the valve clearances today. The inlet pistons were spot on, 3 exhaust pistons were quite off - worst being 3 thou off. So now all inlet are 9, exhaust are 11. Oh and the plugs are all fine.

She runs smoother, there seems to be a bit more torque now too! However the only remaining problem is only when cold at low revs when I first drive off in first and second gear it is quite aggressively jumpy still :( only remaining thing is the MAP sensor I presume? :(

Little FYI to possibly help the diagnosis, the oil is a little low on the lower dot on the dipstick. It is fuchs titan race pro s 5w40 from the service in January. I've ordered another litre for a top up. No idea if this will contribute to it being crap on cold... :/
 
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Hi Jak,

If your oil is below the line I wouldn't even think about driving the car!

Wait till it gets delivered, seriously.
 
Its on the minimum dot and I'm taking it very steady too. Waiting for top up to arrive
 
Jak said:
Its on the minimum dot and I'm taking it very steady too. Waiting for top up to arrive
Click to expand...

It's so annoying!

I remember when I had no choice but to put Sainsburys oil in to get home..

Safe to say the next day that was drained and replaced!
 
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