I just recently put a JDM p73 ITR ecu into my car witha USDM ITR motor. I am experiencing some hesitation and power loss when the throttle is more than 25%. Under VERY light throttle it is fine, however if I start to go uphill or accelerate at all, it will act like timing is way off. It has only been in the car for 10 miles, however I did reset the ecu. Should I just keep driving and let the ECU learn the new timing for the different motor? Any help is much appreciated!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by huskmusk &raquo;</TD></TR><TR><TD CLASS="quote">I just recently put a JDM p73 ITR ecu into my car witha USDM ITR motor. </TD></TR></TABLE>

Why?
You do realize that there are additional sensors on the USDM motor, and even then the JDM ECU is not calibrated for a USDM motor.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by zygspeed &raquo;</TD></TR><TR><TD CLASS="quote">Why?
You do realize that there are additional sensors on the USDM motor, and even then the JDM ECU is not calibrated for a USDM motor. </TD></TR></TABLE>

The JDM p73 should still drive normal on the USDM setup.
Try shooting your ignition timing, replacing your cap/rotor/fuel filter etc.

 

I have "JDM ITR" chipped ecu and it runs fine for me.

try this first tho.

drive around until your car is fully warmed up.
disconnect battery + (before you put your ecu.)
and connect the battery
start the engine let it run for 10 mins. Do not touch gas..

mine was kind of weird but after i did these.. it runs perfect ..but i think i burn more gas with jdm ecu than my stock obd2 ecu

 

Bad idea!!! JDM ecu's are tuned for 11:1 compression, 290cc injectors, and 96-100 octane....

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by huskmusk &raquo;</TD></TR><TR><TD CLASS="quote">I just recently put a JDM p73 ITR ecu into my car witha USDM ITR motor. I am experiencing some hesitation and power loss when the throttle is more than 25%.</TD></TR></TABLE>

Is your motor completely stock? What modifications have you made? Do you have a test pipe or free flowing cat? If you do, what provision did you make for the cat sensor?

Did you reset the ECU as described by itr1244 or by some other method?

Where is your initial spark advance, and what fuel octane are you using? I think you could be spot on when you say it feels like the spark advance is way off. There might be something causing the computer to feel that it would be dangerous to implement the full spark advance.

Most of us would not find the OEM JDM ITR ECU an ideal solution, but you should not be having anything like the problems you are having.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by MiraiZ &raquo;</TD></TR><TR><TD CLASS="quote">Bad idea!!! JDM ecu's are tuned for 11:1 compression</TD></TR></TABLE>

The compression difference will not affect the way the car runs that much, I've ran my 12.5:1 compression 2.0L map on a 1.8L with 11.5:1 and it ran fine, not perfect, but didn't hesitate.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by MiraiZ &raquo;</TD></TR><TR><TD CLASS="quote">290cc injectors</TD></TR></TABLE>

All B-series injectors are 240cc.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by MiraiZ &raquo;</TD></TR><TR><TD CLASS="quote">and 96-100 octane....</TD></TR></TABLE>

Japanese octane rating is MON, which is generally 7-9 points lower than the equivilant RON rating. So effectively, 100 MON is 93-91 RON.

The only real difference between the JDM ITR P73 and USDM ITR P73 is the ignition tables and emissions check, no secondary O2...etc. Which is the benefit of running it. You can retain OBD2 diagnostics like the OBD2 port for inspection, while eliminating some of the emission control devices on your car.

Pull your ECU fuse out for a couple minutes. If the car does not run correctly, put your USDM ECU back in. If the problem persists, it could be a number of things. Easy things to check/fix are plugs/wires, cap/rotor, fuel filter, and possibly send your injectors out to be cleaned. All of those are recommended factory services anyways, so might as well tackle them while you're troubleshooting this problem.

Good luck,
Marshall

 

Thanks for the great info.. however after reseting the ecu like stated above by another member, the car now is almost inoperable. When I step on the gas at all now it will cut out, almost as if the ecu is cutting off fuel to the motor. I am lost as to what to do now..

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by MiraiZ &raquo;</TD></TR><TR><TD CLASS="quote">Bad idea!!! JDM ecu's are tuned for 11:1 compression, 290cc injectors, and 96-100 octane....</TD></TR></TABLE> It baffles me as to why people think the JDM ECU is gonna give them more power. Unless, the engine is equipped with the same components as the JDM engine, you are not going get a boost in power. If anything you'll lose power. JDM ECU's needs a minimum of like 94+ octanes for the fuel maps to work in your favor. The timing is way different too. I suggest finding someone to buy that off you and get a USDM ECU or an aftermarket one tuned for your engine specs.

Sorry to be harsh, but I see stuff like this too much lately.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by MiraiZ &raquo;</TD></TR><TR><TD CLASS="quote">
Sorry to be harsh, but I see stuff like this too much lately.</TD></TR></TABLE>

That's because the prices of stock ITR have dropped so much that there's a whole new batch of people buying basically unimproved ITR and they are learning things the hard way.

The real culprit <u>could</u> be whoever sold the guy the JDM chip for his USDM purpose.

 

SAY MAN!!!! Where are my Plug Wire's I bought????? I know you have gotten My Pm's. This is starting to get Nasty. I will post on every thread you make!!!!!!!!!!!!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by huskmusk &raquo;</TD></TR><TR><TD CLASS="quote">I am lost as to what to do now.. </TD></TR></TABLE>

Is it really that difficult to figure out?

Put the stock ECU back in.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by George Knighton &raquo;</TD></TR><TR><TD CLASS="quote">

That's because the prices of stock ITR have dropped so much that there's a whole new batch of people buying basically unimproved ITR and they are learning things the hard way.

The real culprit <u>could</u> be whoever sold the guy the JDM chip for his USDM purpose.</TD></TR></TABLE>


Yeah...well its also really not too hard to come here or any other forum to research FIRST before buying something and complaining that it doesn't work right later.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by MiraiZ &raquo;</TD></TR><TR><TD CLASS="quote">Yeah...well its also really not too hard to come here or any other forum to research FIRST before buying something and complaining that it doesn't work right later. </TD></TR></TABLE>

You know how it is. Excited people with a new Hype R get sold a bill of goods.

 

I have the same ECU on my car,
Didn't give me any prblems as yours does.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 92TypeR &raquo;</TD></TR><TR><TD CLASS="quote">

Japanese octane rating is MON, which is generally 7-9 points lower than the equivilant RON rating. So effectively, 100 MON is 93-91 RON.

Marshall</TD></TR></TABLE>

Japanese fuel may be Rated in MON but it is the equivalent of 100 RON fuel, thats why turbo motors like skylines/EVO's/Subarus etc etc that are imported into my country from japan run like crap when fed 95ron fuel and suffer detonation and piston damage. I use regular 95ron fuel in my car most of the time but now and then i fill with 98 and add a bottle of octane booster to bump it up a little more and the difference after a few miles of driving is night and day!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mugenracer &raquo;</TD></TR><TR><TD CLASS="quote">Japanese fuel may be Rated in MON but it is the equivalent of 100 RON fuel, thats why turbo motors like skylines/EVO's/Subarus etc etc that are imported into my country from japan run like crap when fed 95ron fuel and suffer detonation and piston damage.</TD></TR></TABLE>

All the fuel test articles I've seen has shown a considerable difference in anti-knock index (AKI) levels between RON and MON, where given two samples of fuel with an equal rating in RON and MON, the RON will have a higher AKI. To make two samples of gasoline, one RON and one MON,have the same AKI the MON would need to have an octane rating 7-9% higher than that of the RON.

The owners of those turbo cars you mentioned may also have increased their boost levels and are running too much boost beyond what the fuel can handle. That is very well the reason for the damage you hear about, because even on 92 octane, an acquaintance of mine has never had any problems with his Skyline(s).

What is the octane rating in Europe? I always thought it was MON also.

If you want to you can poke around through this. http://www.faqs.org/faqs/autos/gasoline-faq/part1/

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mugenracer &raquo;</TD></TR><TR><TD CLASS="quote">I use regular 95ron fuel in my car most of the time but now and then i fill with 98 and add a bottle of octane booster to bump it up a little more and the difference after a few miles of driving is night and day!</TD></TR></TABLE>

I find that interesting, because even with my 12.5:1 compression, if I completely fill my tank with 100 octane, I don't see much of a performance increase whatsoever. I would if I remapped my ECU and tuned the ignition timing. But the Honda ECU won't increase ignition timing, it can only retard timing via the knock sensor. The only reason you would feel an increase in power is if the ECU had already retarded timing, and now is returning to the stock map. Your ECU will not tune itself to run better on higher octane.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by huskmusk &raquo;</TD></TR><TR><TD CLASS="quote">Thanks for the great info.. however after reseting the ecu like stated above by another member, the car now is almost inoperable. When I step on the gas at all now it will cut out, almost as if the ecu is cutting off fuel to the motor. I am lost as to what to do now.. </TD></TR></TABLE>

Put the USDM ECU back in and see if the problem persists...you wont be able to troubleshoot anything until you eliminate the possibility that the ECU you have is shot.

 

on pretty much everything 92TypeR said.