98 EK civic with 05 rsx k20 using 03 EP3 engine harness cylinder 1 misfire

Hondata model coverage & ECU application questions.
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Defcom012
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Joined: Sat Nov 12, 2022 11:52 pm

98 EK civic with 05 rsx k20 using 03 EP3 engine harness cylinder 1 misfire

Post by Defcom012 »

I have a 98 Civic dx 5 spd with 05 RSX base k20 5spd manual, the ecu (Hondata) and engine harness is from a 03 Civic SI. From the first time I started the car before the ecu was fitted with Hondata. The engine was misfiring on cylinder 1, All these parts are new: spark plugs, coil packs, Type-S injectors. Kpro has no errors but it seems like injector 1 is not getting enough power or something. I ordered a new 02-04 rsx engine harness, will be here later this week. If it continues then Ill have to reach out you guys to test the ECU for any faults.

Seems like this problem is common with most swaps, especially with 05-06 rsx base engine (K20A3) and reverting to 02-04 civic si engine harness in any chassis to use Hondata.
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Spunkster
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Re: 98 EK civic with 05 rsx k20 using 03 EP3 engine harness cylinder 1 misfire

Post by Spunkster »

You should try your ECU on a known working vehicle.
Defcom012
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Re: 98 EK civic with 05 rsx k20 using 03 EP3 engine harness cylinder 1 misfire

Post by Defcom012 »

Loopy will do, have you see an ecu with bad injector drivers ?
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Spunkster
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Re: 98 EK civic with 05 rsx k20 using 03 EP3 engine harness cylinder 1 misfire

Post by Spunkster »

Yes, if it is wired incorrectly, it can damage them.
Defcom012
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Re: 98 EK civic with 05 rsx k20 using 03 EP3 engine harness cylinder 1 misfire

Post by Defcom012 »

I went to a Hondata dealer in PA (Import DPS), They stated that they could not find out as to why this problem is occurring. I need to ship this ECU to yall for further testing.
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Spunkster
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Re: 98 EK civic with 05 rsx k20 using 03 EP3 engine harness cylinder 1 misfire

Post by Spunkster »

What is the serial number that is on the K-Pro board inside the ECU?
Defcom012
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Re: 98 EK civic with 05 rsx k20 using 03 EP3 engine harness cylinder 1 misfire

Post by Defcom012 »

Spunkster wrote: Wed Mar 08, 2023 10:21 am What is the serial number that is on the K-Pro board inside the ECU?
Sorry for the long delay, the ecu is good and it seems to be within the harness. The obd scanner is not even coming up with a code for a misfire on Cylinder 1

I checked the compression, power going to the coil and injector. Both are getting 12volts. Coils, plugs and injectors are new.

I’ve also heard the junction box can be a failure point as well.
Im waiting let the snow melt off the car and check the wires from the coil to the junction block.
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