Performing Honda K24a3/AST5 6spd Conversion

Had the 3rd H/L switch I've bought from overseas fail on me (whilst @ Carlisle) - the worst part is, they don't come out the dash without flying apart. Added a Volvo 240 modded switch. Looks more ungainly in the pic than it is - it's not in the way of the stalks.

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kmead said:
Some frustrating issues there.

I think the issue with the oil is that the engine is running hot and therefore the water to oil tempering device is also running hot. I would bet you find the coolant temp at that spot is also around 220 or not much below that just before the oil cooler.

Bringing down the temperature of the coolant would likely do a lot towards cooling the oil.

Have you considered moving to an external coolant pump? More volume of coolant through the engine and then the radiator should elicit cooler temps as has been proven on the two 1.9l X’s in Germany. Perhaps the Honda pump is adequate for the extremely short runs around a FWD engine compartment but the parasitic loss of long pipe runs is slowing things down enough that you just are not moving enough coolant? Your radiator certainly seems up to the job.

Running too lean is not good on so many levels, not least of which being how hot the engine runs.

I would see what the remap can do for you and then start making other changes as above after that.
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Yeah, I really, really, don't want to add additional complexity to the system. I'm going to wait until after the dyno tuning & see. Under load & high rpm the coolant temps are where they should be 180 degrees as per t/stat fully open temp.

Once the tuning is done, I'll see if more is needed. I've also had the occasional idle CEL, which comes with a wildly fluctating idle once the code sets, with that, there are a bunch of software paramaters for idle target, shift / decel compensation, etc., so I don't want to go down the rabbit hole on that either, until tuning is squared away.
 
I was able to resolve the idle CEL / fluctuation, which is a relief. The 70mm TB has to be set so the butterfly is essentially closed - just open a fraction so the plate won't stick when throttle is snapped shut. With that, the TPS has to be then adjusted to go from 0% as soon as the throttle is opened - that's the tricky part as the TPS can also cause the plate to stick a fraction open if it's not perfect. After that, the other issue is that with the 70mm TB, it's impossible to get a base idle below 1050, at least that's my current experience. I tried setting it to 850 / 950 - 1000, and each time results in the idle hunting & the CEL, as the system cannot achieve the idle target.

Before last weekend's drive, I had the idle target @ 1050, and had had no issues for hundreds of miles, so I set it back & got the TPS just so it registers when opened, but doesn't hang the plate on throttle pedal release.

Now, I can leave it alone until the dyno tune in just a little more than a weeks time :)
 
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lookforjoe said:
I was able to resolve the idle CEL / fluctuation, which is a relief. The 70mm TB has to be set so the butterfly is essentially closed - just open a fraction so the plate won't stick when throttle is snapped shut. With that, the TPS has to be then adjusted to go from 0% as soon as the throttle is opened - that's the tricky part as the TPS can also cause the plate to stick a fraction open if it's not perfect. After that, the other issue is that with the 70mm TB, it's impossible to get a base idle below 1050, at least that's my current experience. I tried setting it to 850 / 950 - 1000, and each time results in the idle hunting & the CEL, as the system cannot achieve the idle target.

Before last weekend's drive, I had the idle target @ 1050, and had had no issues for hundreds of miles, so I set it back & got the TPS just so it registers when opened, but doesn't hang the plate on throttle pedal release.

Now, I can leave it alone until the dyne tune is just a little more than a weeks time :)
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Could the idle level be due to the increased opening of the larger throttle plate?

How does the Hondata/Honda ECU measure air? Sorry this isn’t something I have delved into on the Hondas I have.
 
kmead said:
Could the idle level be due to the increased opening of the larger throttle plate?

How does the Hondata/Honda ECU measure air? Sorry this isn’t something I have delved into on the Hondas I have.
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Absolutely. With the previous 80mm TB, I couldn't get even close to 1K idle rpm. I'll ask the tuner about it, as it may also be a combination of timing advance/fuelling that is preventing me from getting a lower idle at this point, I dunno.

The K series EMS uses a MAP sensor mounted in the TB assembly.
 
That behavior, where the engine could not be cooled below about 3-4k rpm, was exactly what was wrong with my car. The problem was traced to the single action thermostat. Replacing it with a dual action Beta unit made all my cooling problems go away and now the car runs at a rock steady 190 no matter what the running condition. I don't recall what your thermostat situation is.
 
lookforjoe said:
I was able to resolve the idle CEL / fluctuation, which is a relief. The 70mm TB has to be set so the butterfly is essentially closed - just open a fraction so the plate won't stick when throttle is snapped shut. With that, the TPS has to be then adjusted to go from 0% as soon as the throttle is opened - that's the tricky part as the TPS can also cause the plate to stick a fraction open if it's not perfect. After that, the other issue is that with the 70mm TB, it's impossible to get a base idle below 1050, at least that's my current experience. I tried setting it to 850 / 950 - 1000, and each time results in the idle hunting & the CEL, as the system cannot achieve the idle target.

Before last weekend's drive, I had the idle target @ 1050, and had had no issues for hundreds of miles, so I set it back & got the TPS just so it registers when opened, but doesn't hang the plate on throttle pedal release.

Now, I can leave it alone until the dyne tune is just a little more than a weeks time :)
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Yes, setting the idle can be tricky in ECU. I got good help from my tuner to get it right. It is a combination of values/settings for idle control air valve, fuel ratio and timing advance. In my case having the butterfly completely closed (TPS 0%) worked the best. I also put a diode on the Volvo PWM idle valve to make it work correctly.
 
Pete Whitstone said:
That behavior, where the engine could not be cooled below about 3-4k rpm, was exactly what was wrong with my car. The problem was traced to the single action thermostat. Replacing it with a dual action Beta unit made all my cooling problems go away and now the car runs at a rock steady 190 no matter what the running condition. I don't recall what your thermostat situation is.
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The thing is, the engine will run cool below 3k moving, just not at idle or at specifically 3-3.5K range. I'm just gonna see what happens after the tune. I did have problems with the T/stat arrangement - but that was because the Volvo housing was offset from the Honda housing, and the temp differential meant the (87c) T/stat was never seeing that temp & therefore not opening all the way. I resolved that by putting a 160F T/stat in, that leveled the coolant temp at 185-190 range.
 
Moved the bay fan sensor - also swapped it out for a 187F VW one - made a bracket to hang it over the exhaust. Now, when the car is sitting in traffic, the fan comes on. That makes me happier.

EDIT: original Bay fan controller HERE

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Stationary air temp over the exhaust when the fan kicks on is around 220F.

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Wow, what a lot of work and pics of the work. Thanks Hussein. Have both an X 1/9 and a stock 1995 Honda Integra VTIr (Acura in US) Despite mileage the Honda is still on the road. The X 1/9 awaiting restoration. Not long hopefully. Maintaining the 1982 X 1/9 pretty much stock.
 
lookforjoe said:
Got the call that they are done with the tune. I'll pick it up after work tomorrow. I did ask for some Dyno pics and / or video.
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Maybe it is a good idea to not attend the dyno run. My tune took half a day and listening to the old girl screaming at top revs for several hours made me nervous.
 
Proper graph

Hussein Holland Fiat K24 Dyno Graph-1.png


So, I'm not driving it. There are a number of issues with the tune. Waiting for some answers.

1) it won't idle when coming to a stop - rev's increase to 2-3K & AFR goes to 12.
2) No fuel cut on deceleration - also runs rich AFR's.
3)I heard knock at part load. Checked the tune -Knock enrichment chart is zero'd out

knockretard.png


4) less power up top than before - I see in the tune that cam angle has been limited to 20º

cam angle.png
 
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