Honda Insight w/Acura TSX engine - Ecomodding

[Ecky]

I feel like my thread has been light on details and pictures for a little while now, so hoping to correct that.

Got my A/C working yesterday.

Pin A27 (blu/blk) on the Insight ECU is "AC ON", which is 12v that passes in series through the climate control and then pressure switch (which regulates A/C line pressure). This is supposed to go into the ECU, which can then decide whether or not to pass on that 12v through pin A17 (red) to the A/C clutch relay.

On the RSX (from which I took my ECU), pin E18 is the clutch output, so straightforward enough, just connect Insight harness wire A27 to RSX ECU pin E18 and the ECU should be able to turn the A/C compressor on and off.

The RSX, however, does not have a dumb 12v signal for A/C, but instead uses a multiplexer for input. Luckily KPro (aftermarket ECU chip) allows reassigning inputs, and one common way to work around this is to reassign the VTEC Pressure Switch (ECU B9, blu/blk) which is not used in JDM motors to an A/C input. Amusingly, the wire colors are the same for VTP on the RSX and AC ON on the Insight harness, so it's blu/blk to blu/blk.

[Ecky]

Unfortunately, for whatever reason it didn't work. The ECU is not detecting an input toggle and isn't activating the clutch out. Still going to need to troubleshoot. So, I just bypassed the ECU altogether, the "AC ON" wire to the A/C clutch relay wire.

The only downside to this I can see is that the A/C clutch will still engage even if the engine is off. KPro isn't smart enough yet to up engine idle when A/C toggles, otherwise that would be a possible disadvantage too.




From there, it was just a matter of getting the Accord A/C compressor I used connected to the wiring harness. The Accord uses a 3 pin connector with two grounds, whereas the Insight harness for A/C uses a 1-pin for power and relies on engine ground straps for grounding. I cut the Accord connector off and soldered the wire from my Insight compressor, and viola! I have air conditioning again.

Here's a picture of the otherwise stock Insight A/C system on the Acura TSX K24 engine:

[Ecky]

While I was at it, I installed a Dakota Digital SGI-8 E tach converter, which corrected my tachometer reading 33% high with no apparent latency. Following the wiring diagram above, the tach signal I needed to interrupt is E26 from the RSX ECU and is also conveniently the same color as the tach signal on the Insight harness.





Still need to sort out the temperature gauge. I believe the sensor is just a varistor, but the RSX sensor uses a different resistance so the Insight gauge jumps from "low" to "overheating" a few minutes into my drive.

[Ecky]

Beyond that, I installed a new knock sensor (from K-Tuned) so I can more safely play with engine parameters.




Exposed underbody, need to redo my belly pan!




Another shot of the engine in the bay:

[California98Civic]

Why does that 1st Gen insight engine bay look sooo short? Was the image compressed somehow ir is it an optical illusion caused by that relatively large K-engine?

[mpg_numbers_guy]

IIRC it's shorter than my Civic's was; I think the angle of the camera might be making it look shorter than it actually is. There is a lot of awesomeness going on under that hood though so I might be mistaken.

[Ecky]

Originally Posted by California98Civic

Why does that 1st Gen insight engine bay look sooo short? Was the image compressed somehow ir is it an optical illusion caused by that relatively large K-engine?

A little of both, I think. Here's a pic of the original bay, and another with the new engine:










The Insight's ECA1 engine is essentially an L series, it's a short stroked version of the Fit engine, with one cylinder lopped off. The Fit has a very tall but not deep engine bay. It's actually relatively hard to shoehorn a K series engine into the bays of older 90's Hondas which used D series engines because the bays are not tall enough - those engines had less height, and tended to have long, low engine bays. The oil pans end up hanging low under the cars. In the case of the CRX, you actually have to cut a hole in the hood to close it, whereas there's still plenty of vertical clearance in mine.

While the weather was nice today I put the interior of the car back together a bit and gave it a bath. Not too shabby for 250k miles.

Camera-mirrors are going back on soon!








I find it helps very much for me to keep my car clean, it seems to affect how positively I feel about it.

[California98Civic]

Looks great. After a long period of just keeping the car running and not caring what it looks like or how clean it is, I started this month to do an extremely long overdue thorough cleaning of the interior. It's starting to come together, a few minutes a day, and I like the look of it again. I look forward to driving it. The interior of your Insight is still in really solid shape. Have you tried any cleaning techniques with the floor mats? I've been battling to save my original 1998 floor mats, but I think I'm going to lose that fight. There are a couple stains I just can't get out.

[Ecky]

I think that's as good as they're going to get, and nobody makes replacements.

[hayden55]

Get some weather techs. My 7 year old mustang still looked brand new when I sold it thanks partly to those mats.