If you've done a JDM H22 Swap, check in here

[devtec]

It seems from going over all the relevant threads, that a significant number of people running JDM engines in the US experience a bad hesitation/stumbling/misfiring/low power problem at lower RPMs (1000-4000rpms).

People have gone crazy going through great efforts to solve this problem with little sucess, including replacing or cleaning components in all the following categories:

IGNITION
spark plugs, wires, distributor, distributor cap & rotor

AIR
PCV valve, EGR valve, EGR intake ports, throttle body

FUEL
fuel filter, fuel pressure regulator, fuel injectors

SENSORS
knock sensor, MAP sensor, TPS sensor


Whenever someone seems to solve the hesitation problems, it is temporary or an inconsistent fix. Not all cars with the hesitation are probably having the same problem, yet the high frequency of JDM engines with hesitation suggests there is a common thread.


The one thing that JDM engines do all have in common is higher compression, and that the engines and their ECUs were designed to run the higher octane fuel available in Japan.

I'm beginning to agree that this is the most likely explanation. I think the root cause of the hesitation is the knock sensor sensing knock due to the lower octane fuels available in the US detonated in the higher compression engines. My hesitation problem is especially bad, and I am running an S Spec H22 with 11.0 compression.


So if anyone has more info on this, let's make this thread useful.

- If you've done a swap, state what kind: regular JDM, Type S, S spec, OBD1, OBD2, etc.
- If you are having the hesitation problem, say so and describe it.
- Any new definitive fixes, theories, etc. For example, if you are using octane booster has it consistently solved the problem? If you are running a P28 or P72 with P13 knock board and a Hondata, has that solved your problem? Has getting your fuel injectors balanced been a long-term solution?

 

[eg6sir]

no need to post this 3 times..

 

[reikoshea]

It seems from going over all the relevant threads, that a significant number of people running JDM engines in the US experience a bad hesitation/stumbling/misfiring/low power problem at lower RPMs (1000-4000rpms).

People have gone crazy going through great efforts to solve this problem with little sucess, including replacing or cleaning components in all the following categories:

IGNITION
spark plugs, wires, distributor, distributor cap & rotor

AIR
PCV valve, EGR valve, EGR intake ports, throttle body

FUEL
fuel filter, fuel pressure regulator, fuel injectors

SENSORS
knock sensor, MAP sensor, TPS sensor


Whenever someone seems to solve the hesitation problems, it is temporary or an inconsistent fix. Not all cars with the hesitation are probably having the same problem, yet the high frequency of JDM engines with hesitation suggests there is a common thread.


The one thing that JDM engines do all have in common is higher compression, and that the engines and their ECUs were designed to run the higher octane fuel available in Japan.

I'm beginning to agree that this is the most likely explanation. I think the root cause of the hesitation is the knock sensor sensing knock due to the lower octane fuels available in the US detonated in the higher compression engines. My hesitation problem is especially bad, and I am running an S Spec H22 with 11.0 compression.


So if anyone has more info on this, let's make this thread useful.

- If you've done a swap, state what kind: regular JDM, Type S, S spec, OBD1, OBD2, etc.
- If you are having the hesitation problem, say so and describe it.
- Any new definitive fixes, theories, etc. For example, if you are using octane booster has it consistently solved the problem? If you are running a P28 or P72 with P13 knock board and a Hondata, has that solved your problem? Has getting your fuel injectors balanced been a long-term solution?

Its definitely not the fuel octane. They just use a different way to calculate it than we do in the states. Thats why its higher.

https://hondaswap.com/reference-materials/us-octane-vs-other-countries-octane-ratings-59435/

I fixed mine when i swapped a chipped p28 (no knock board). Fixed it right up. The problem was reduced significantly by a new fuel pump, seafoam, a new intake and header. It went completely away with the new ECU.

 

[devtec]

Sorry about the multiple posts, wasn't showing up for me...

reikoshea: didn't realize that at all about the different rating system. That's great reading. But then this begs the question of why the stock ECU problem in the first place? Putting in a P28 or a P72 has seemed to work for other people too...

 

[reikoshea]

Sorry about the multiple posts, wasn't showing up for me...

reikoshea: didn't realize that at all about the different rating system. That's great reading. But then this begs the question of why the stock ECU problem in the first place? Putting in a P28 or a P72 has seemed to work for other people too...

Yeah, i've got no idea bro. I just know it worked...i was desperate...id done everything i could think of but that, and it worked beautifully. Maybe you're getting a USDM P13 mated with a H22A and its just not right for the low end. Thats all i can think of.