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iDTEC losing power in mid rev-range

Wehey

Wehey

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Location
UK
Car
Accord Type S
Hi,

This is my first post, having big problems with my 18-month old Type S. When I first bought the car, I had it professionally re-mapped by an excellent tuning company who unleased the stock 180ps to approx. 220ps. The power and smoothness was instantly noticeable and the car has driven like a dream for nearly 36,000 miles (serviced at the correct intervals by Honda dealer).

About 3 weeks ago, I noticed that when I put my foot down on the throttle, rather than buckets of power (in whatever gear) throwing me forward, I got a lacklustre attempt to accelerate for 500-1000 rpm and then the start of a boost (like severe turbo-lag) before I had to change gear. It made motorway overtakes (5th and 6th gear) painful and even dangerous. I've taken the car back to Honda under warranty and after having it for a week they deduced the turbo needed replacing (v. unlikely). The turbo was replaced and after running a 400 mile motorway journey this weekend, it is very clear the problem hasn't been fixed.

I've lost faith in their abilities now (as they admitted they were having to send screen-shots to Honda UK during the diagnostics) and wondered if anyone else had experienced the problem and whether they found a fix? I'm a desperate man, I want my Type S back!

Thanks,
Mark
 
Have you had the stock map reinstated?

Bit harsh on Honda otherwise ;).

Also worth checking for loose or holed vacuum hoses. These have been missed in the past.
 
Mark this is the 1st case iv heard of this on a type S.
You are lucky though Honda have not spotted the map as your warranty will be invalid due to your remap.
 
Who tuned your car? Take it back to them to revert to stock and then let Honda do their diagnostics. Hard to diagnose something like this on a tuned car as you don't know what parameters the tuner has worked with.
 
Fair point, thanks guys. The re-map was only done on the guarantee that it was 'undetectable'. I appreciate it would invalidate the warranty so haven't mentioned it. The company was Torquing BHP outside of Cambridge, they came with great reviews.

Surely, the first thing I expected Honda to do was instigate a default map? I was kind of sold on the idea I'd have to take it back to the tuners when I collected the car, but no, still the mod'd map. If the readings were unpredictable the first thing I would do is default everything.

Anyhow, I came to the same conclusion it was airflow so I've checked hoses, intercooler, air-sensor and even simply the air filter- can't see anything obvious. I can see a new turbo though so at least I know they did carry out the swap!

Thanks,
Mark
 
Honda will have no reason to remap a car it ***umes us stock. In theory - based on the 7th gen - pulling the battery will reset the ecu, but not the map.

If the map was undetectable (sic) there is nothing for Honda to see.

Other things remain a possibility of course.
 
No map in the world is undetectable, let's just be clear on that.

What they mean is that the information Honda diagnostic tools expect to see when they plug into the car, will be presented to them in the correct format i.e. hardware and software revisions etc.

However should the dealer wish to start logging flows and pressures, it will become obvious pretty quick.

I'm not saying it's the tuners fault, in fact I've not even heard of these guys and the Honda's are one of our signature vehicles.. BUT if you want to give Honda a fair shot at fixing the problem, you need to let them work on a standard car so they can work with the variables their tools/software are designed to see.
 
Just a quick update (in case anyone is reading with a similar problem in the future)-

I was on the motorway last Friday (haven't been back to Honda as yet) and 'ping' I lost all power and the multi-display shows an error. After stopping and checking the manual, the code tied up with a DPF fault. Not your usual DPF regeneration required, but full on (!) 'go straight to a dealer'. I took the car straight to the nearest dealer via the Honda Satnav and they took a look over the car. After about an hour, they said they'd managed to clear the light by doing a thorough regeneration but that 'the power wasn't all back'. They suggested it may clear further with more driving otherwise a new DPF maybe required, apparently this one is/was pretty blocked.

Anyway, the moment I got back in the car it was sounding better (quieter, smoother), it was pulling far more smoothly and although still top-end limited, the car was hugely improved. I have the car booked in with the local dealer again now armed with this new information and I believe it could be a winner.

Does this make sense? Could the DPF really be causing this significant loss in torque and high(er) rev powerband?

Thanks,
Mark
 
Mark there was 1 case here from a member with a DPF problem.
I'm sure the was a long wait to get a new one for the fix.
I will do some digging to find the thread.
 
Thanks Brett, appreciated.

I'll post back tomorrow evening when Honda have taken another look. I'm using a different dealership to last time- fresh eyes an' all that.
 
Yes mate of course it can cause these problems!

At that mileage, what is most likely is that the tuner has tuned it outside the thresholds which allow for safe regeneration in the background i.e. it's not a DPF safe remap. Even tuned, as long as it's a DPF safe remap, it should allow the DPF to last 80k miles and above.

If you can get the DPF replaced under warranty then cool, otherwise you'll need to have the DPF smashed through and tuned correctly with DPF OFF.

Have a look at our Facebook page (in signature below) for some examples of DPF OFF we do and what it involves - irrespective of the car, the principle is the same
 
I've been looking at your website, really impressive, wish I'd heard of your company sooner!

IF the DPF is replaced under warranty (IF), are you able to perform a DPF safe remap? On the other hand, if it isn't replaced- what are my options? It's on a 120k lease so I don't want to be man-handling the exhaust or doing physical alterations.

Thanks,
Mark
 
If it isn't replaced then you can see how long it lasts with the tuning corrected (***uming its bad) to bring it within thresholds... Or you can still have the DPF removed.

Bear in mind when we smash them through, from the outside there are no signs that anything has been done/tampered with you. We would need the car for most of the day in Bradford and I'd need to have the ECU out of the car to tune.
 
Hello,

I received the car back from the second dealership yesterday evening, their job sheet said that the car had passed an injector and turbo test successfully and that the technician carried out another manual DPF regen. I'm not really sure what to think now, the car is better than it has been throughout this whole process but I'm unconvinced it's as good as it was...I might have to accept I'm imagining things now. The DPF regeneration certainly provided the biggest improvement.

Fahad, I've spoken with the original tuner, he says that the map on the car is maintaining the DPF function, I ***ume this is what you meant about 'DPF friendly'? He suspects potentially a faulty DPF sensor that caused the soot to build up beyond the capabilities of auto regeneration.

All in all, my verdict of DPF is not great- what a fundamentally useless, EU loving piece of techno-****! I know everyone moaned about the 'cat' when it was introduced, maybe the DPF will be perfected one day likewise.

Anyway, I'll drive the car and try to enjoy it. Try to convince myself there's nothing wrong with it, as this may genuinely be the case.

Thanks for all your suggestions and help,
Mark
 
Hi Mark. You could always get the DPF removed and re-remapped. I know a lot of Audi and BMW owners go for a DPF delete with great results and no regeneration problems again ;)
 
That's what I'm suggesting mate.

I guess if the car is already tuned you need to give your tuner the opportunity to fix it. no such thing as a DPF sensor, he could be referring to a whole host of sensors including the O2 sensor, Pressure Differential Sensor, Exhaust Gas temp sensor... and DPF's don't rely on a single sensor, they take readings from various sensors and the ECU will then calculate whether it needs to regen or not.

If he's pushed the car hard, he's probably breached at least one threshold which has caused excessive build up on the DPF chamber and totally ruined its lifespan.

At the end of the day, one way or another you will need to replace or remove the part eventually.
 
Fahad, could you send me a PM with your price to bypass the DPF? Once I have an idea of cost, I can make a decision on it. FYI, getting the car to Bradford is not an issue, we have plenty of people we can visit and stay with in the area.

If the DPF is bypassed though, when we MOT the vehicle at the end of lease, will the emissions not register a fail?

Regards,
Mark
 
Mark, I've not seen any DPF deletes causing MOT failures yet. I'll drop you a line.
 
Hi all,

Hopefully my last post on the topic... it's fixed! I've got my Type S fully flying again.

I noticed the other day while driving that if I was more gentle on the throttle, the engine RPM and road speed increased together and although not ferocious acceleration, I got up to speed quicker than putting the pedal to the floor (this just resulted in a lot of engine noise and no increase in speed).

I took a chance and ordered another accelerator pedal switch from the internet (found one in Lithuania for £30 on eBay, second hand) I fitted the new switch this morning in 15 minutes and instantly the car was back to its old self. The acceleration is smooth, the full-throttle position gives me full throttle and everything feels as it was before. Such a simple fix and so effective.

The pedal has 4 (or 5- I can't remember exactly) pins on the connector so I'm guessing it provides independant signals to separate devices on the vehicle. I'm wondering if the pedal was failing, different parts of the system were receiving different position readings and therefore the car just wasn't performing properly- everything out of sync.

Whatever the reason, I'm happy its had a good result and the car's back to normal. I'm wondering whether the DPF and turbo were just red herrings or pure coincidence?!

Anyway, thanks for everyone's input in the post.

Regards,
Mark
 
Nice feedback , and I think a first for that fault.

Glad it is all sorted.
 
A weird one for sure.. hope it holds out for you mate.
 
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