Hello all,
Apologies if this is the wrong section to ask for help.
I have a TVS1320 supercharged K20 in an Ariel Atom with ID1050X injectors and other supporting mods (chargecooler etc), it has been custom mapped on a hub mounted dyno using Hondata Flashpro.
The car has started loosing power towards the top of the rev range, most noticeable in higher gears. The car also cuts out for a split second during these episodes, it feels like an ignition cut. I've checked for boost leaks and am now suspecting something on the ignition side. I have contacted my tuner but they are cannot book the car into the dyno for sometime due to work load. Could any of you kind folks please have a look at the attached logs and offer any advice? I would be extremely grateful if any of you knowledgeable guys could assist, I'm sure the problem is shown in these logs, particularly the "6th gear pull" log which had very noticeable symptoms felt from the drivers seat.
Many thanks in advance for any help.
supercharged K20 in Ariel Atom issue
supercharged K20 in Ariel Atom issue
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Re: supercharged K20 in Ariel Atom issue
VTEC is failing. You can see how boost goes up. Don't run at high rpm on the low cam because the lost motion assembly will float and damage the cam lobes. Since the temperature readings are faulty I'd look carefully at the grounds and wiring.
Don't hold the engine on the rev limiter. You'll drop a valve eventually.
You'll need to get the lambda working too before going any further.
I'd look at the calibration and see what is disabled when it should not be. That will tell you what other faults are present.
Don't hold the engine on the rev limiter. You'll drop a valve eventually.
You'll need to get the lambda working too before going any further.
I'd look at the calibration and see what is disabled when it should not be. That will tell you what other faults are present.
Hondata
Re: supercharged K20 in Ariel Atom issue
Thank you very much indeed for the reply, I really appreciate it.
I've looked at the logs again and thanks to you I can now can see the VTEC dropping out as you said, and the coolant temp and IAT temp both dropping out.
In the "6th gear pull" log, it seems that the VTEC drops out a few tenths of a second after the IAT and ECT start going haywire. Is it possible that the loss of these two temperature parameters is what is then causing the VTEC to drop out? I can see in the calibration that "VTEC minimum coolant temperature" is set to 60 degrees Celsius.
I replaced the lambda once before with an OE Honda sensor, strange that its failed again.
The car has recently been stripped down for chassis work, including engine removal/re-fitting. It's since I've had the car back that these problems have manifested, I'm now wondering if the wiring/earths have been compromised during this work.
Apologies, but how do I check the calibration file to see what is "disabled"? I have the flashpro next to me and connected to my PC, I've got the calibration open.
Again, thank you so much for your help.
I've looked at the logs again and thanks to you I can now can see the VTEC dropping out as you said, and the coolant temp and IAT temp both dropping out.
In the "6th gear pull" log, it seems that the VTEC drops out a few tenths of a second after the IAT and ECT start going haywire. Is it possible that the loss of these two temperature parameters is what is then causing the VTEC to drop out? I can see in the calibration that "VTEC minimum coolant temperature" is set to 60 degrees Celsius.
I replaced the lambda once before with an OE Honda sensor, strange that its failed again.
The car has recently been stripped down for chassis work, including engine removal/re-fitting. It's since I've had the car back that these problems have manifested, I'm now wondering if the wiring/earths have been compromised during this work.
Apologies, but how do I check the calibration file to see what is "disabled"? I have the flashpro next to me and connected to my PC, I've got the calibration open.
Again, thank you so much for your help.
Re: supercharged K20 in Ariel Atom issue
First step is to fix the ECT and IAT.
Check where the main harness ground goes - normally on the intake manifold. Since you are supercharged, it probably is not the stock manifold. If so then the best place for the main harness ground is on the end of the cylinder head. If you have a custom harness ... all bets are off.
Next step after the ECT and IAT would be to see if the lambda is the same problem; if not, fix that too.
Check where the main harness ground goes - normally on the intake manifold. Since you are supercharged, it probably is not the stock manifold. If so then the best place for the main harness ground is on the end of the cylinder head. If you have a custom harness ... all bets are off.
Next step after the ECT and IAT would be to see if the lambda is the same problem; if not, fix that too.
Hondata
Re: supercharged K20 in Ariel Atom issue
Understood, and again, many thanks.
You are correct, originally it ran a JRSC manifold with the associated supercharger, but now runs a MercRacing inlet manifold with charge cooler core for the TVS 1320.
I believe the Atom uses a "standard" Honda harness, so any alterations should be limited. There are three large multi-pin connectors plugged into the ECU.
I will adhere to your instructions and investigate the loom for the ground connection. If there is any ambiguity, I was planning on running new/extra ground wires to ensure good ground continuity (I will go to the cylinder head as you recommend).
I just had a quick look at the coolant temperature sensor. It has one wire from the loom going to it (which I assume is the signal wire back to the ECU). The sensor itself has two terminals; as only one is connected to the loom, I assumed the other terminal must go to ground to complete the circuit. However, there is equal resistance between each terminal and the engine block. I expected one terminal to be dead short to the engine block if it is indeed supposed to be grounded.
I will carry out further investigation when time allows over the next few days and update this thread.
Again, thank you so much for your time and help, it's very much appreciated!!
You are correct, originally it ran a JRSC manifold with the associated supercharger, but now runs a MercRacing inlet manifold with charge cooler core for the TVS 1320.
I believe the Atom uses a "standard" Honda harness, so any alterations should be limited. There are three large multi-pin connectors plugged into the ECU.
I will adhere to your instructions and investigate the loom for the ground connection. If there is any ambiguity, I was planning on running new/extra ground wires to ensure good ground continuity (I will go to the cylinder head as you recommend).
I just had a quick look at the coolant temperature sensor. It has one wire from the loom going to it (which I assume is the signal wire back to the ECU). The sensor itself has two terminals; as only one is connected to the loom, I assumed the other terminal must go to ground to complete the circuit. However, there is equal resistance between each terminal and the engine block. I expected one terminal to be dead short to the engine block if it is indeed supposed to be grounded.
I will carry out further investigation when time allows over the next few days and update this thread.
Again, thank you so much for your time and help, it's very much appreciated!!
Re: supercharged K20 in Ariel Atom issue
Just a quick minor update.
I ran two new additional ground cables, one from the cylinder head and one from the inlet manifold. Unfortunately it made no difference, hondata logs still showed ECT and IAT feeds dropping out intermittently at higher rpm, with VTEC also dropping out.
I also measured continuity between the single wire going to the ECT sensor and pin B23 on connector block B, which according to the FN2 ECU diagram I have should be the correct termination point for the ECT signal. Unfortunately, this was open circuit so I may have the wrong pin out diagram. The ECU is getting an ECT signal (according to Hondata Flashpro logs), the issue is it's dropping out.
I've got to call my tuner again later this week to see if they can fit me in this month.
I'm not sure if I have the knowledge to do much more myself at this stage.
Again, thank you for your time and effort posting all your help.
I ran two new additional ground cables, one from the cylinder head and one from the inlet manifold. Unfortunately it made no difference, hondata logs still showed ECT and IAT feeds dropping out intermittently at higher rpm, with VTEC also dropping out.
I also measured continuity between the single wire going to the ECT sensor and pin B23 on connector block B, which according to the FN2 ECU diagram I have should be the correct termination point for the ECT signal. Unfortunately, this was open circuit so I may have the wrong pin out diagram. The ECU is getting an ECT signal (according to Hondata Flashpro logs), the issue is it's dropping out.
I've got to call my tuner again later this week to see if they can fit me in this month.
I'm not sure if I have the knowledge to do much more myself at this stage.
Again, thank you for your time and effort posting all your help.
Re: supercharged K20 in Ariel Atom issue
Hi all, just a bit of an update for anyone interested.
My car went on the Dyno at the garage that originally mapped it for me a few years ago. They "believed" that the issue was a poor/bad connection in a multi pin plug, and after attending to that the car apparently behaved itself on the Dyno.
Unfortunately, I took the car away and first time out it's doing exactly the same as before. New data logs show exact same issue ie ECT and IAT signals giving spurious readings under load at high rpm with the VTEC dropping out.
I've had another look myself. I've now realised that I was previously looking at the wrong coolant temperature sensor. The ECU coolant sensor has two wires, one being the signal (red/white) going to middle ECU grey connector block B pin B23, the other being the signal ground (green/black) going to ECU connector block B pin B33. I've disconnected the ECT sensor from the loom and checked continuity of the wiring with a multimeter. I'm getting a max resistance reading of 0.3 ohms for both wires from the sensor connector back to the ECU connector. These readings do NOT deviate when I twist/pull/wiggle the loom, so it appears that the integrity of the ECT sensor wires is "good", although I appreciate that I tested this without the engine running and therefore nothing was under load. Also these readings obviously exclude the actual ECU from the circuit.
I repeated the above with the IAT sensor wiring and had the same results, so again the wiring integrity appears sound. The three IAT sensor wires go through the same middle grey ECU connector. The connector which the garage believed to have issues was not this one.
I am starting to think that the issue could well be the ECU itself. My car is booked in to go back on the Dyno again in a couple of weeks time.
The ECU is stamped 37820-RRB-315 and I am using an ECU pin out diagram for the FN2 which so far is correct. Over here in the UK, searching that ECU model number brings up results that are all USA based which I don't understand why? If it turns out I need a new ECU, and at this stage I don't know, it seems it's readily available stateside for around 600 dollars or so, but not in the UK. Are there other versions of this ECU which are compatible and available in the UK?
Also, is there a wiring diagram for the FN2 wiring harness available anywhere online? I cannot find one anywhere. I have the ECU pinout, but not an actual wiring/circuit diagram to help with fault finding.
I've ordered a brand new genuine Honda ECT sensor to try when it arrives, but due to the nature of the fault (both ECT and IAT sensors giving bad readings under exactly the same very specific conditions) I very much doubt it's a sensor issue, but at least I will be able to rule it out.
Any other help or information is very much appreciated.
My car went on the Dyno at the garage that originally mapped it for me a few years ago. They "believed" that the issue was a poor/bad connection in a multi pin plug, and after attending to that the car apparently behaved itself on the Dyno.
Unfortunately, I took the car away and first time out it's doing exactly the same as before. New data logs show exact same issue ie ECT and IAT signals giving spurious readings under load at high rpm with the VTEC dropping out.
I've had another look myself. I've now realised that I was previously looking at the wrong coolant temperature sensor. The ECU coolant sensor has two wires, one being the signal (red/white) going to middle ECU grey connector block B pin B23, the other being the signal ground (green/black) going to ECU connector block B pin B33. I've disconnected the ECT sensor from the loom and checked continuity of the wiring with a multimeter. I'm getting a max resistance reading of 0.3 ohms for both wires from the sensor connector back to the ECU connector. These readings do NOT deviate when I twist/pull/wiggle the loom, so it appears that the integrity of the ECT sensor wires is "good", although I appreciate that I tested this without the engine running and therefore nothing was under load. Also these readings obviously exclude the actual ECU from the circuit.
I repeated the above with the IAT sensor wiring and had the same results, so again the wiring integrity appears sound. The three IAT sensor wires go through the same middle grey ECU connector. The connector which the garage believed to have issues was not this one.
I am starting to think that the issue could well be the ECU itself. My car is booked in to go back on the Dyno again in a couple of weeks time.
The ECU is stamped 37820-RRB-315 and I am using an ECU pin out diagram for the FN2 which so far is correct. Over here in the UK, searching that ECU model number brings up results that are all USA based which I don't understand why? If it turns out I need a new ECU, and at this stage I don't know, it seems it's readily available stateside for around 600 dollars or so, but not in the UK. Are there other versions of this ECU which are compatible and available in the UK?
Also, is there a wiring diagram for the FN2 wiring harness available anywhere online? I cannot find one anywhere. I have the ECU pinout, but not an actual wiring/circuit diagram to help with fault finding.
I've ordered a brand new genuine Honda ECT sensor to try when it arrives, but due to the nature of the fault (both ECT and IAT sensors giving bad readings under exactly the same very specific conditions) I very much doubt it's a sensor issue, but at least I will be able to rule it out.
Any other help or information is very much appreciated.
Re: supercharged K20 in Ariel Atom issue
What is the FlashPro serial number?
Re: supercharged K20 in Ariel Atom issue
Serial number is FP-SI-INT-24281 "Civic Type R outside North America"
Many thanks!
Re: supercharged K20 in Ariel Atom issue
Intermittent issues are usually wiring related and not ECU related.
If you decide to replace the ECU you must return to stock from the online menu first then unlock the FlashPro then you should be able to lock to the replacement ECU. You will have to use a US ECU for this.
For a wiring diagram you may need to talk with a Honda dealer.
If you decide to replace the ECU you must return to stock from the online menu first then unlock the FlashPro then you should be able to lock to the replacement ECU. You will have to use a US ECU for this.
For a wiring diagram you may need to talk with a Honda dealer.
Re: supercharged K20 in Ariel Atom issue
Thank you very much.
It's bizarre that I need to use Flashpro specifically for vehicles outside North America, yet I have to use an ECU specifically from North America. I really don't understand that, as it's a complete contradiction. How can the non-American only Flashpro work with an American market ECU?
It's bizarre that I need to use Flashpro specifically for vehicles outside North America, yet I have to use an ECU specifically from North America. I really don't understand that, as it's a complete contradiction. How can the non-American only Flashpro work with an American market ECU?
Re: supercharged K20 in Ariel Atom issue
You have a special FlashPro specifically for an Ariel Atom and it needs the US ECU.
Re: supercharged K20 in Ariel Atom issue
Ah ok, fair enough. Can I ask what is special about the Flashpro specifically for the Ariel Atom? I assumed its using "standard" Honda K20 running gear. Also, do you know the reason Ariel use an American ECU when it's for a car sold in the UK? It seems overly complicated. I'm sure the engine/box and wiring are FN2 which is for the European market, I'm curious as to why Ariel are using such a mix mash of different region parts which you wouldn't ordinarily find paired together anywhere else.
Re: supercharged K20 in Ariel Atom issue
Because there was not Civic SI released in the Europe and these ECU's were abundant and were what all R&D were done on.
Re: supercharged K20 in Ariel Atom issue
Another little update.
I fitted a new genuine Honda ECT sensor. Same fault symptoms.
I disconnected the loom from the IAT sensor and inserted a resistor of a specific value to make the ECU think that it was seeing constant 40 Deg C (thereby effectively removing the actual IAT sensor). Again same fault symptoms.
I ran a new signal ground wire from ECU connector block B pin B23 up to the ground connection on both the ECT and IAT sensors. I ran this new ground wire in parallel with the existing loom. Fault symptoms remain.
I had the car booked back in with the garage for more dyno time but when I told them what I had done they said that they had planned to run new ground wire so I had beat them to it. They believe what's been done so far has eliminated a loom or sensor issue and advise that it looks to be the ECU that's breaking down.
As I need to order the ECU from USA and have it shipped to UK, could you kindly advise if the only ECU that will work is the exact same one I have now (37820-RRB-315). Googling that part number brings up vendors in the USA selling ECUs with slightly different parts numbers that apparently supercede the original part number. Obviously I do not want to order something that is not compatible. If I need exactly the same then I will ensure that's what I order.
Many thanks
I fitted a new genuine Honda ECT sensor. Same fault symptoms.
I disconnected the loom from the IAT sensor and inserted a resistor of a specific value to make the ECU think that it was seeing constant 40 Deg C (thereby effectively removing the actual IAT sensor). Again same fault symptoms.
I ran a new signal ground wire from ECU connector block B pin B23 up to the ground connection on both the ECT and IAT sensors. I ran this new ground wire in parallel with the existing loom. Fault symptoms remain.
I had the car booked back in with the garage for more dyno time but when I told them what I had done they said that they had planned to run new ground wire so I had beat them to it. They believe what's been done so far has eliminated a loom or sensor issue and advise that it looks to be the ECU that's breaking down.
As I need to order the ECU from USA and have it shipped to UK, could you kindly advise if the only ECU that will work is the exact same one I have now (37820-RRB-315). Googling that part number brings up vendors in the USA selling ECUs with slightly different parts numbers that apparently supercede the original part number. Obviously I do not want to order something that is not compatible. If I need exactly the same then I will ensure that's what I order.
Many thanks