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I purchased an ecu and harness from someone on ebay and it looks like he sent me the wrong wiring harness. See the pic of one of the plugs and the pic of my ecu...
104108

104109


Is there an adapter harness I can use?

This is going into a 66 Datsun Roadster....

Thanks for your help.

Rob
 

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That is not a wrong harness. That’s a C101 plug on the harness you bought (RSX). It does not plug into the ECU. You need some type of universal conversion harness to use it.

In the original chassis, that plugs into the RSX female end of the interior harness.

This is what you need to make it work. There are other manufacturers that make these so this is an example. Click the link and read the examples of vehicles it is used in (such as Ariel Atoms, Lotus Elises, Mr2s, etc).

 

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I did not mention it, but on the conversion harness there is also another plug that goes into the E position of the ECU. So the engine harness has the A, B, and C101 male plugs. The conversion harness has the C101 female end and the male E plug. The A, B, and E plugs all go into the ECU
 

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Discussion Starter #5
I have some connectors that I can't identify. Can you help?
104118

The one in my hand is the oil pressure connector. What is the one that is circled?



104119

These two plugs are after the injectors. Don't know what they are for....




104120


1. Intake air temp? Does it go behind the throttle body?

2. ??

3. ??

4. ??



104121


1. ??
2. ??



104122


These are at the end of the charge cable. Did they go to a fuse box? One has continuity to the positive battery terminal, the other does not. I moved my battery to the trunk. Can I get rid of the battery terminal and the circled connectors?




104123

Ring terminal to starter positive supply?
Knock sensor?




Thanks for helping me straighten these out. I tried searching but all I found were pinouts for the ecu connectors.
I would like to get rid of those that I don't need and clean this up a bit. Because this is going in a RWD car, the intake will be "flipped" so the throttle body is towards the front of the car.

I did order the conversion harness, but they are back ordered. I'm trying to get this done for a car show in April, but I don't know if I can make it or not with the cable delayed.

I appreciate any help you guys can give.

Rob
 

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Discussion Starter #6
Also, when I moved the battery to the trunk, I put a 180 amp circuit breaker on the cable supplying the starter.
 

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Lost post. Let me see how many I can answer...

Edit: Pictures do not show up in the quotes. Either match it up to your post or follow the link in the quote to see the pic.

I have some connectors that I can't identify. Can you help?
View attachment 104118
The one in my hand is the oil pressure connector. What is the one that is circled?
It's for the VTEC oil pressure switch. You should have another connector in the same area for the VTEC solenoid, both plug in on top of the spool assembly.

View attachment 104119
These two plugs are after the injectors. Don't know what they are for....
Top circle looks like the last injector. Assuming you have a base model RSX harness? Bottom I believe is the intake manifold runner control valve connector.

View attachment 104120

1. Intake air temp? Does it go behind the throttle body?

2. ??

3. ??

4. ??
1. IAT. There's a hold in the intake tube that presses into. You'll have to install it in the in the intake before the throttle body.
2. I believe is the MAP connector.
3. I believe is the EVAP purge valve connector.
4. I believe is the TPS connector.

There are so many in the same area here I'm having a difficult time telling them apart.

1. IACV connector.
2. Starter solenoid.

View attachment 104122

These are at the end of the charge cable. Did they go to a fuse box? One has continuity to the positive battery terminal, the other does not. I moved my battery to the trunk. Can I get rid of the battery terminal and the circled connectors?
Yes those go to the under hood fuse box. One should go straight to the battery, the other should go straight to the alternator. They're connected together in the fuse box with a fuse in between, I believe 100 amps.

View attachment 104123
Ring terminal to starter positive supply?
Knock sensor?
Correct on both.
 

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Discussion Starter #9
Awesome!!
Thanks for your help. This was a JDM K24. I didn't see the VTEC oil pressure connector by the solenoid, but I could have looked right at it...

The intake is from Kpower. It has an IACV.
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The intake runner control valve was originally to change the flow of the intake manifold for more low end torque and fuel mileage, correct?

I'll get everything cleaned up, wires extended, and re-wrapped.

Engine going in next week. Then waiting for the conversion harness. I'll take it to have the exhaust fabbed while I wait.

Thanks again.

Rob
 

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Awesome!!
Thanks for your help. This was a JDM K24. I didn't see the VTEC oil pressure connector by the solenoid, but I could
Ah yeah the JDM engines don't have that pressure switch.

The intake runner control valve was originally to change the flow of the intake manifold for more low end torque and fuel mileage, correct?
Yes. It was only on the base model RSX and CRV as far as I'm aware. Your harness must be from one of those.
 

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Arouse the DAMPFHAMMER!
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Wow, what a nice Datsun Fairlady K-swap project. Looks like a dream car condition. Almost a pity to K-swap it. Don't you loss value when it is swapped? Anyway, I like it, I am no hardcore oldtimer guy. It should provide fun, open tasks and passion input is intrinsically.

intake runner control valve
Never heard of that. What does a Intake Runner Control Valve? I only know the Intake Air Control Valve to control idle speed by bypassing the throttle body with a small amount of air over a stepper motor controlled "valve".
 

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The plastic intake manifold on the K20A3 has a large valve than opens/closes to modify the length of the intake runners. Longer length for lower RPM, shorter length for higher RPM.

104134
 

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The plastic intake manifold on the K20A3 has a large valve than opens/closes to modify the length of the intake runners. Longer length for lower RPM, shorter length for higher RPM.
Many thanks Brotatochip 🆙. Very nice technique to erect a better low end oscillation power of the air in the lower engine speeds. Thanks for sharing the picture :).
 

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Discussion Starter #14
Intake - yeah, very cool.
As far as the Datsun value, it already had a motor replacement. Same motor, but not "numbers matching". Maybe sometime in the future it will matter, but I bought it as a driver to have fun in. The originality was cool until I could barely keep up with the moms in their minivans drinking Starbucks. LOL. There are definitely people on the 311 boards (model) that are not happy about what I am doing. And, I normally don't put a Honda in a Datsun. I try to keep the components the same brand, but the SR20DE engines are getting scarce. Others are hard to fit and dont usually top 200 hp like the K24(a2).

Thanks again Brotatochip. I'll probably have more questions when wiring up my Hondata ECU.
 

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Thanks for your insight of the Datsun oldtimer handling.

SR20DE engines are getting scarce
Nice 97 mm bore bitch engines, but their head ports are behind what Honda K-series put on the table. Here these going for less then 1000 Euro over the table. Are there any bigger differences in the production years of the SR20DE?
 

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Discussion Starter #16
I haven't been involved with the SR20's in a long time. Even then I did not get very deep in them. Nissan boards or wiki would have those answers.
 

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I haven't been involved with the SR20's in a long time. Even then I did not get very deep in them. Nissan boards or wiki would have those answers.
Thanks for your reply. Anyway, it will be a Honda K-series, which is the must better aggregate performance-wise. I think it is a bit taller because of the bigger clearance demand of the iVTEC system under the valve cover. It has some lacking areas on the electric side: TPS and grounding sensitivity. Beside that is is one of the most durable and resilient engines I know in the I4-NA-field, but also here there are some sensitive fields: VTC actuation, TCT and oil tribology when using harder valve actuation dynamics (bigger cams). Don't use not specified oil weights above SAE40 if not built for (which makes for me also no sense in a standpoint of oil chemistry and therefore tribology if boosted or if built).
 

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I had initially looked at the Ecotec LCV. Another 200+ HP I4. The bottom end of that motor is supposedly built to handle double that HP. Unfortunately, it is 2-3" taller and I am already fighting ground clearance issues.

K series was my choice for size, availability of parts, power, reliability.
 

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Discussion Starter #19
Started wiring today. Got everything laid out and took off the plastic moulded channels, elbows, etc.

I need to extend the MAP, TPS, and Intake Air Temp cables since they are all on the other side of the engine now (RWD, the intake is "flipped"). I also have a B series TPS. The new connector I bought has all of the leads black and not color coded. Awesome. From what I can tell, the wires are in the same "order" on the K and B series. When looking at the wire side, clip up at 12:00, Ground on the left, signal in the center, 5V on the right? So I can just keep the wires in their same positions on the new connector.

I had to order a new temp sensor. Waiting for that to arrive...
 

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Ecotec LCV. Another 200+ HP I4....K series was my choice for size, availability of parts, power, reliability.
Interesting info about the GM LCV, I didn't know that it is even taller as the K24, which is 19 mm taller then the K20 engine.

I also have a B series TPS.
Good choice, bypassing the weak link of the K-series.

Ground on the left, signal in the center, 5V on the right?
@KBuilt would now it exactly. You may find this info in his built thread.
 
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