Hondata

First of all, the ecu is a p28, the calibration used is attached(danny ed ctr cam) and the datalog named ifo1 is my 10.28 @ 148 pass and the ifo3 datalog is my 10.62 @ 142 pass. The only thing in the setup that has anything to do with the ignition is an M&W ignition box but it was doing this when I had an MSD box as well.
I noticed on the datalog(ifo 1) that the timing at the end of the run was 13 deg and the timing on the map at the same place was around 17. At first I thought it was the IAT comp, but it only retards 3 deg at 140 degrees and the car barely touched 140 deg at the end of the run. I also noticed it seemed to retard it much earlier as well. Then, on the next run(ifo3) it was 9 deg at the end of the run when it should have been around 18. I assume that is what slowed the car down and made it lose mph. My question is, why is it pulling timing and why was it worse on one run?

It is because the ECU thinks the engine is overheating. The coolant temperature is about 220 degrees on the run where the timing is retarded the most.

yeah,that it what it acts like, but the ect in compensation is set at 0 for all temperatures.is that the only setting that would change that or is there something else i am missing?

The compensation tables are only for cold temperature advance.

so you can't turn the ect retard off? surely there is an adjustment for that.i just don't know where it is.it is not uncommon for a drag car to get well over 190 degrees.

Hondata wrote:The compensation tables are only for cold temperature advance.

is this startup only?

as we are goin to run ice box for the intake?
i was hoping to save the secondary map for other things.

any answers?

We'll address this in a future release. You really need to keep the water temperatures down if at all possible.

turbotypeR wrote:any answers?

my temperature reading on mine was off a little, I think it was due to the engine swap and the sensors being different between the 2 engines. I had to measure the temperature with a seperate sensor with another guage, then I adjusted the value that the ECU was reading by installing a resistor so that it was more accurate.

For now, can I remove the coolant sensor? Will I have any issues besides not being able to read ECT on the datalog?

turbotypeR wrote:For now, can I remove the coolant sensor? Will I have any issues besides not being able to read ECT on the datalog?

you have one option if you're choosing to fake out the ECU, dyke the wire going to the ECT sensor, install a resistor to match the suggested temperature for your engine and put it straight to chassis ground.

There is one problem with this solution, when you first start the engine up it's not going to compensate for the cold engine, so it may be hard to start for the first few minutes and it may act sluggish.

If you remove the sensor from the engine or dyke the wire it will show a CEL and go into limp mode.

Preccord00 wrote:

turbotypeR wrote:For now, can I remove the coolant sensor? Will I have any issues besides not being able to read ECT on the datalog?

you have one option if you're choosing to fake out the ECU, dyke the wire going to the ECT sensor, install a resistor to match the suggested temperature for your engine and put it straight to chassis ground.

There is one problem with this solution, when you first start the engine up it's not going to compensate for the cold engine, so it may be hard to start for the first few minutes and it may act sluggish.

If you remove the sensor from the engine or dyke the wire it will show a CEL and go into limp mode.

i don't have a iacv anymore.this is a race car,so cold start is really not an issue.i was just gonna take another sensor and tie it up in the engine bay and leave it plugged up until the new version comes out with a provision for it.

Dosn't make a difference. if you leave the sensor hanging it wont have a path back to the ECU and will cause a fault. By putting a resistor in the path of the ECT wire and putting it to ground you're simulating the ECT sensor. Go out and buy a pack of resistors from radio shack, keep playing with the resistors untill you find the temperature you want it to be and it'll stay at that temp reading no matter what.

As stated above, removing the ECT sensor and leaving it hang will give you a CEL and put it in limp mode.

Find out for yourself, remove the sensor and see what happens, place a resistor in the path and check the reading on the datalog.

Why will it trhow a code? Is it because the temp will be too low or does it lose ground when it is taken out? It will still be hooked up, so if it loses it's ground, you could hook ground to the body of the sensor, but if it is because the temp was too low, I can see where it would throw a code.

turbotypeR wrote:Why will it trhow a code? Is it because the temp will be too low or does it lose ground when it is taken out? It will still be hooked up, so if it loses it's ground, you could hook ground to the body of the sensor, but if it is because the temp was too low, I can see where it would throw a code.

It's because it loses a ground from the sensor, it's possible to just ground out the sensor if that's the route you want to go, I'm not entirely sure how the ECU will react to thinking it's cold all the time though.