Hondata

Status Update 11-Jul-2022

Issues resolved. vTEC is working without issue. The latest progress on the project, and casual cruising with my son, has yielded results.

The question others would ask... "what did you do to fix the issue".

There was 1 code present for IAC (code was no surprise, as I ...

Got snow last night. Plus busy weekend with kids activities. So, going to come up with next weeks game plan...

Is there another method of testing that does not involve testing the ECU in a different vehicle?

I don't have another car to test it in, nor any friends with Hondas. I've reached out to ...

Spunkster

I pulled the attached calibration from the ECU. I let the engine come up to temp, then collected the attached datalogs (2nd Gear and 3rd Gear).

At VTEC x-over (RPM & throttle parameters) it registers the boost cut.

I did collect additional datalogs with a few different Parameters ...

Attached are 4 pictures.
1: as pulled from the vehicle
2: Cover removed, Analog & USB cord removed
3: Hondata removed
4: Bottom of board

I gave both side of the board a good visual, and good smell. Not seeing anything odd, nor any burn electrical smells. This ECU is my "good" one, which I trust ...

Can do! Anything specific you want to see?

I did a little electrical inspection on the Pressure Switch side, per Honda (and AllData) service. I get KO battery voltage at the switch connector. On the sensor, I get 0.1-0.2-ohm across the 2 pins (passes continuity requirement). Regarding the ground ...

Status update 10-MAR-2022:

Snow is gone and temps are finally warming up to the 40’s, so can continue diagnosing. Fixed a small coolant and fuel leak, now to focus on VTEC.

I resolved the IAT code. “Someone” (cough, me... idiot), had the wrong connector on the sensor. Thank you Honda for not ...

Spunkster,

Seems that all signs are pointing to ECU being NOK. I verified line resistance from A4 ECU connector to VTEC solenoid and get 0.3-0.5 ohm (passed). With Key-On/Engine-Off, I Test Outputs, and see no alteration in that line voltage, nor is there any audible "click" of the solenoid. Based ...

Spunkster

Got the new MSD in, back up and testing with cleaned up grounds. Still get the "boost cut" at VTEc cross-over.

I did check the solenoid resistance. It passed. I also checked the pressure signal circuit from the ECU, it shows 12v at key-on.

I know that I can use s300 to test ECU outputs ...

Spunkster,

Just updating you. Small setback. My MSD 6AL crapped out, so, bigger issue to address (need to pull the box).

The cylinder head is fully grounded via woven ground strap to directly to the head. I have verified it's grounded via DVOM. I've also confirmed that the VTEC solenoid is fully ...

Hello Spunkster,

Attached are the Engine, Trans and Thermostat Ground pics. I have verified that all grounds are grounded via multi-meter and visually (no paint, rust or grease adding resistance). I did ground both the valve cover and the cylinder head (never understood why Honda put the ground on ...

logs and tunes used (not sure why it didn't load the first try)

Forgot to put the details in the initial post.

Hondata SManager 2.7.5.0 Build 1435
Vehicle: 94 Del Sol
Engine: built d16y8
P28 hondata chipped ECU
Mods: Bored Y8 block with deck plate, YCP Pistons (+0.5mm), SCAT rods, Crower Turbo Cam ...

Spunkster & Others,

I will take a look later today / tomorrow, and get the multi-meter out to verify the VTEC solenoid is grounded.

I did three 2nd gear test pulls, and the issues is associated directly to vTEC engagement.
Test 1: vtec set at 4750rpm
Test 2: vtex set at 5250rpm
Test 3: No VTEC ...

Update, I am going to alter the vTEC engagement RPM setting to see if it alters the Boost Cut, and also try without vTEC too. My opinion, these two steps will see if the issue is related to vTEC.

Still will be open to advise, recommendations and things to look at.

Greetings All,

I've attached the tune on the s300 ECU and the Datalog.

Issue: During full throttle acceleration, boost cut engages at ~4800-5000rpm (approximately same time vTEC engages), resulting in a sadness. I know I can go partial throttle, but full-throttle is an always results in the boost ...

Thanks for the feedback. Went ahead and wired up as expected.

One follow on question regarding units for my gauge display. the AEM gauge is a liner gauge 0.5-4.5v (called AEM) for 0-100 PSI. In the analog inputs I've set it up as "custom" with the corresponding voltage & value. Is there any work ...