Performing Honda K24a3/AST5 6spd Conversion

dcioccarelli

Dominic Cioccarelli
one additional idea I was toying with is a latch pin using the stock cable, nothing complex like the factory latch which I have no room for.

sketch at bottom left

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so, I bought a inexpensive latch that looked to be appropriate overall sizing - it will be mounted in this general vicinity:

View attachment 55559

I'll add back the ear that is used to locate the cable sleeve, higher up to align with some part of the lever. I'm probably going to drill the lever & pass the cable through it, I have sufficient cable for that. I do need to figure out the cable throw so I can either offset the mechanism (as shown), or cut down the pin, if I need the latch set further to the right. This is mean pulling the lever & lifting the corner of the cover whilst holding the lever, but that's not a big deal - I have the additional side scoop on mine that works as a great handle. Once it's lifted slightly, the lift piston takes over.

You could combine that with an inexpensive boot release solenoid like this:


Cheers,
Dom.
 

lookforjoe

True Classic
You could combine that with an inexpensive boot release solenoid like this:


Cheers,
Dom.

I used one of those many years ago for the trunk. I don't have room for that behind the panel.

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darwoodious

Darin Nelson

Bryce-o-rama

True Classic
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lookforjoe

True Classic
Worked on the latch, heat shielding & putting the headers back in today - not going to send it out for Ceramic coating at this time. Cost would be around $500 or so by time one factors shipping to & from OK. I'll revisit the idea after I see how the heat soak is with the heat shielding I've added.

heat shield on right side
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solenoid shield, new header gasket & header back in place, with new Honda flange bolts

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left side sheilding

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made a bracket to locate the release cable

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cross brace back in

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Welded the latch housing to the top plate

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problem is I didn't actually check to see if the cable was in the right place to attach to the latch - I need to move the cable back a few inches & mount the locating bracket to the inner wall. For now, the latch has a stop that allows it to be left unlatched, so I'll address it later

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I want to get the rest of the exhaust on tomorrow, so I can run the motor & see how it sounds

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lookforjoe

True Classic
Ran the engine today. Had an IMMEDIATE cel for O2 heater circuit :mad:

Also runs overly rich, but maybe that's just because I didn't run it to normal operating temp.

I have to fault trace the O2 heater circuit control wire (ECU A10 - O2 pin 3). The O2 sensor is a new (in June) Denso 234-9066 O2 sensor intended for the 05 TSX. It seems highly unlikely that it has failed after only a couple months of actual use. Maybe it doesn't like being so far downstream - however that has no bearing on heater circuit, and I'm not getting AFR metering error codes.

nice to get it outside at least!

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When I got done with the Volvo cam business, I spent a little time pulling the engine cover cable out of the lower routing & positioned it up under the upper cross brace, so I can now add the support plate to locate the cable sleeve.
 
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lookforjoe

True Classic
pulled the ECU A connector & checked continuity

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Turned out, the O2 heater wire from the O2 plug to A10 was severed a few inches from the plug, inside the conduit.

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fixed that.

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Drove the car until the engine was normal operating temp. After that, I got P1172 code - which I don't see a clear explanation for (2005 Acura RSX ECU). Also, the AFR's are rich at idle 13.7, 13.8 (held throttle @ steady 2K here to see if it changed, it didn't) AFR sweeps when driving, but clearly running rich. The System WBO2 is a new genuine Denso 234-9066 I installed over the summer, and I haven't driven the car for months.

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I wondering if having the O2 so far downstream compared to where it was, is changing the values compared to what the system has learned. Blue cable O2 is the Denso, heat wrapped one is the AEM WB02 sensor. I guess I'll refresh the ECU fist, and see how that goes. Nothing has changed other than the length (and probably back pressure)

The engine bay cover gets REALLY hot, even with the whole back open - can't imagine how bad it's gonna be all closed up.
 

lookforjoe

True Classic
Reflashed the ECU, made no difference. P1172 and now P2A00 error codes after driving a mile our so. If I clear the codes & let it idle, its fine, but as soon as I drive a mile or so, codes come back.

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kmead

Glutton for punishment
As I am getting plenty of Honda code education of late, this is the leading, pre catalyst O2 sensor being out of range. Likely either a wiring issue or a failure of the sensor. The front one is Bank 1 the post catalyst is Bank 2, at least on a Honda Element. The P2A00 is just reinforcing the information the first code was throwing.

However as your engine is running rich, the O2 sensor would be delivering a signal suggesting such and from Honda’s emissions perspective, it would be the engine running out of range with no ability to reign it in or that the attempts to do so have been ineffective.

Could it be fouled from running rich? I suspect you need to find a way to lean it out as you are outside the parameters set for AF ratio.

My experience with OE parts is that the rear one is the one that tends to fail more often (which makes little sense).

 
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lookforjoe

True Classic
As I am getting plenty of Honda code education of late, this is the leading, pre catalyst O2 sensor being out of range. Likely either a wiring issue or a failure of the sensor. The front one is Bank 1 the post catalyst is Bank 2, at least on a Honda Element. The P2A00 is just reinforcing the information the first code was throwing.

However as your engine is running rich, the O2 sensor would be delivering a signal suggesting such and from Honda’s emissions perspective, it would be the engine running out of range with no ability to reign it in or that the attempts to do so have been ineffective.

Could it be fouled from running rich? I suspect you need to find a way to lean it out as you are outside the parameters set for AF ratio.

My experience with OE parts is that the rear one is the one that tends to fail more often (which makes little sense).


I think it's running rich at idle because the sensor is out of range - Everything was honky-dory prior to the current dis-assembly & work. Amazon is going to warranty/replace the defective sensor, so I'll hopefully have this resolved early next week.
 

dcioccarelli

Dominic Cioccarelli
I think it's running rich at idle because the sensor is out of range - Everything was honky-dory prior to the current dis-assembly & work. Amazon is going to warranty/replace the defective sensor, so I'll hopefully have this resolved early next week.
Maybe double check the cable going to the sensor as well. If one lead was severed, there could be a similar fault elsewhere?

Cheers,
Dom.
 

lookforjoe

True Classic
Maybe double check the cable going to the sensor as well. If one lead was severed, there could be a similar fault elsewhere?

Cheers,
Dom.
Indeed - I checked the continuity of the signal wires as part of the harness check. Also, a severed wire for the sensor would set a different permanent CEL, this one only comes on after driving, not if code is cleared when idling.
 

lookforjoe

True Classic
OK! I got a new 234-9066 replacement & installed that today. No error codes, and system WBO2 sweeps & displays 14.7 AFR range at idle.

However... the AEM WBO2 controller still shows 13.8 or richer AFR reading at the same idle condition. To check the (LSU4.9) sensor, I swapped it out with a brand new AEM sensor ( I have 3 of these AEM units, one in each car), the display values were the same, and still approx 1AFR richer than system readings, at any given load point. After that, I switched sensor locations - moving the system WB02 into the collector, and the AEM WBO2 into the cat, approx 10" downstream of original location.

The system WBO2 readout was unchanged, works as it should. The AEM displayed a new reading, which was also not good - now it's approx 2 AFR leaner than actual (!) I don't know if this means the controller is whacked - since swapping sensors didn't change the display, I don't see how changing location could actually be the controller & not a sensor issue. I've emailed AEM tech support, as the unit is less than a year old (April'21)

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switched sensors - system WBO2 now in collector (on right)

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TonyK

True Classic
Hi Hussein sorry to hear you are having problems with the O2 sensor. When I did my Abarth swap I too had O2 sensor problems and it amounted to a connection at the ECU 140 pin plug. A problem that seems to haunt these computer controlled engines is that they are self learning and go to some wild default if everything is not right. Drivable yes, but not right. I changed 3 O2 sensors, pinned, rang out wires 20 times but until that O2 sensor clears the code you will have problems, the engine will not learn and AFR will be out of wack. Once resolved every thing was fine, it is just getting there that is a long and daunting task. Keep with it, impressive build thanks for sharing your wins and your troubles.


TonyK.

Grimsby Ontario Canada.
 

lookforjoe

True Classic
Hi Hussein sorry to hear you are having problems with the O2 sensor. When I did my Abarth swap I too had O2 sensor problems and it amounted to a connection at the ECU 140 pin plug. A problem that seems to haunt these computer controlled engines is that they are self learning and go to some wild default if everything is not right. Drivable yes, but not right. I changed 3 O2 sensors, pinned, rang out wires 20 times but until that O2 sensor clears the code you will have problems, the engine will not learn and AFR will be out of wack. Once resolved every thing was fine, it is just getting there that is a long and daunting task. Keep with it, impressive build thanks for sharing your wins and your troubles.


TonyK.

Grimsby Ontario Canada.
Thanks Tony
It was pointed out that the system may have been detecting a lean condition at idle due to leakage in my loop section when the system WBO2 was downstream (incorporated flex), which would explain why the AEM was showing rich in the first location, and now lean in the downstream location. I will need to pull that loop & make sure the flex didn't crack with all my install/removals whilst figuring out the layout.
 

lookforjoe

True Classic
Since it poured with rain today, I could not drive or test the system with closed loop disabled, so I took the time to remove the loop from the header collector to the cat. I found no leaks or cracks in any welds or the flex coupler, however, the VBand coupler at the header collector was sooted all over the mating surfaces, and inside the clamp, so it clearly was leaking at idle after the first (originally AEM) O2 & before the second (originally System) O2 - which corroborates the statement from Lotus on K20a.org -

"The other way round, so AEM before leak and Honda after would lead to the AEM reading rich if downstream Honda lambda would regulate to 1.00."

- where my system O2 read 14.7 range whilst AEM read 1 AFR richer.

And

"Upstream Honda lambda would read 1.00, but the second sensor sees excess oxygen and reads lean."

- which is what I had after switching the two O2 locations.

I cleaned & sealed the flange outer lip & left it to set. I'll see how it runs tomorrow.
 

lookforjoe

True Classic
I fabricated the bracket need to make the latch work today. Just as well, as the cheap push latch has already failed, presumably from the heat of the exhaust

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open

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closed

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had to cut down the main pin to fit inside the cover hoop

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also moving the bay fan sensor so it's directly above the heat generated by the headers. Drilled & tapped plate for M14x1.5 - have it above the runner that is closest to the cross plate

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kmead

Glutton for punishment
I fabricated the bracket need to make the latch work today. Just as well, as the cheap push latch has already failed, presumably from the heat of the exhaust

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open

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closed

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had to cut down the main pin to fit inside the cover hoop

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also moving the bay fan sensor so it's directly above the heat generated by the headers. Drilled & tapped plate for M14x1.5 - have it above the runner that is closest to the cross plate

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That fan may never stop running :)

One wonders if a fan blowing upward from under the car would help much.
 

lookforjoe

True Classic
That fan may never stop running :)

One wonders if a fan blowing upward from under the car would help much.

The plastic grille mesh I used is already buckling from the heat, and I've only driven it 3-4miles, maybe. I'm going to have to open up another slat on the right & add bracing that aligns with the top slats for the mesh.

I think moving, the flow up from below is decent - stationary, it's cooking the engine cover, but the fan wasn't running at all with the sensor where I had it.
 
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