Part throttle, no load - Strange issue

Glimpse · Post by **Glimpse** » Wed Mar 02, 2005 9:03 am

I'm having a strange problem that occurs when I'm holding a constant throttle and there is no load on the motor (i.e. it's in neutral). The injectors seem to simply turn off. This happens on regular intervals every half second or so.

I have attached a datalog for reference.

Pertinent information is:

KManager version 1.1.8.0
Pertinent Modifications:
Toda N2 cams
Injen CAI
PRC IM
Toda RH
2.5" catback

Anyone have some insight on this problem?

Post by **Hondata** » Wed Mar 02, 2005 10:58 am

Can you post the calibration as well?

Glimpse · Post by **Glimpse** » Wed Mar 02, 2005 11:58 am

Hondata wrote:Can you post the calibration as well?

Sure thing. It's attached here.

foobari · Post by **foobari** » Wed Mar 02, 2005 1:44 pm

Are you sure you don't have the launch limiter set at around 2500rpm? It seems to be set at 5500rpm in you kalibration, but might be a good idea to re-check it.

Glimpse · Post by **Glimpse** » Wed Mar 02, 2005 1:55 pm

foobari wrote:Are you sure you don't have the launch limiter set at around 2500rpm? It seems to be set at 5500rpm in you kalibration, but might be a good idea to re-check it.

It's correctly set at 5500rpm. I verified when I was at the track on Sunday and was launching from 3000rpm when I noticed this oddity. The launch limiter acts much faster than pulses over a half second like I'm seeing here...

Post by **Hondata** » Wed Mar 02, 2005 2:30 pm

We put your calibration in a vehicle and tested it - everything was fine.

First check that the ground connection to the cylinder head is good and check the ECU connectors are pushed all the way in.

When did you first notice the problem? Does the car do anything else odd?

Glimpse · Post by **Glimpse** » Thu Mar 03, 2005 9:22 am

I checked the ground connection on the cylinder head and it is properly grounded. I unfortunately did not have a chance last night to check the ECU connectors. I'll re-seat the ECU at lunch today and confirm.

I first noticed this issue when attempting to launch at the track on Sunday. However, I did the cylinder head and K-Pro work a few months ago. With no racing during the off-season, I've never had a reason to try this. So unfortunately I cannot be sure how long this issue has been present.

In terms of other oddities -
1. I occasionally get a CEL for A/F stuck lean due to a bad pin on the connector for the primary O2 sensor. Reseating it fixes this, and it correctly reads A/F.

2. My ECU makes a hissing/clicking sound when the car is first started (i.e. Ignition turned to ON position) and also when new calibrations are uploaded. As someone with an EE background it makes me weary when I hear noises from solid state electronics, but this has been occurring since the day I bought the car so I never put much thought into it.

Aside from that, everything is fine. Datalogs during cruising and WOT are normal (the injectors maintain their proper behavior). The vehicle gets 28-32mpg, and performance is as expected. I have over 10,000 miles with the current setup.

Post by **Hondata** » Thu Mar 03, 2005 10:00 am

#2 sounds very unsual. Pull the lid of the ECU and switch the ignition on and see if you can isolate the noise. The only sound you should hear when uploading is the main relay clicking off, then the fuel pump re-priming once the upload has finished.

Glimpse · Post by **Glimpse** » Sat Mar 05, 2005 5:31 pm

Hondata wrote:#2 sounds very unsual. Pull the lid of the ECU and switch the ignition on and see if you can isolate the noise. The only sound you should hear when uploading is the main relay clicking off, then the fuel pump re-priming once the upload has finished.

I'll see if I can do this sometime this week.

I did notice something interesting today - this issue does not occur during cold startup. That is, when the motor is warming up and is at fast idle, it will properly hold speed instead of exhibiting this pulsation issue when I hold it at the same RPM as before (3,000 for example).

Glimpse · Post by **Glimpse** » Sun Apr 17, 2005 2:28 pm

I wasn't able to track down any noises internal to the ECU; it's rather faint sound.

However, by use of the substitution method I have determined that it is an ECU problem. I plugged my ECU into another RSX with nearly identical mods (me: CAI, Toda valve springs, Toda RH, N2 cams, thin headgasket, catback; him: SRI, Toda valve springs, DC RH, N2 cams, thin headgasket) and the same thing happened on his car with my ECU. With his ECU, behavior was normal.

I'll be calling on Monday for tech support, but is there a way I can do a "K-Pro exhange program" so you can determine the problem? Keep in mind that this issue was not present before the ECU was K-Pro'd.