Cold Start - Post Start Fuel Trim

[Johnny_9]

Parameter>Fuel Trim>Cold Start>Post Start Fuel Adjustment

At what tempreture range is "Cold Start" operative?

Is it correct to understand that if the Engine is fully warmed up 95 celsious, there is no adjustment from this?

[Hondata]

It always operates, but the effect is reduced to zero by about 80 degrees C.

[Johnny_9]

How to put out Ignition Timing to a Dyno for a MBT tune?

[Johnny_9]

On-board diagnostics (OBD) monitors any problems with your vehicle. It also alerts you when the vehicle fails below performance requirements. OBD1 and OBD2 are two types of OBD systems. If you desire OBD1 over OBD2, you can convert the system back to its original self. An OBD1 jumper harness allows the on-board diagnostic system to perform like an OBD1. The process takes some time, but with a little patience you can get the job done.


Purchase an OBD1 jumper harness. Your automotive professional may have such a harness for your system. Alternatively, you can purchase one at many automotive stores. This allows you to convert your OBD2 to an OBD1 system.


Locate the OBD2 in your vehicle. It should be within three feet of the steering wheel. Examples would be under the dash, in front of the passenger seat, behind the ashtray or in or around the center console.


Locate the ICM (Ignitor) input port. Connect the yellow and green wire from the jumper harness into it.

Look for the CKP (Crank Position) input. Attach the light blue and white wires into it. Insert the yellow and black wires into the CYP (Cylinder Position) inputs.

Locate the TDC (Top Dead Sensor) input ports. Insert the green and red wires into those ports.

Plug the dark blue wire into the RPM Lead Signal input ports. Attach the black and yellow wires to the remaining RPM ports

[Johnny_9]

Is there a Fuel Comp. ECT buffer (time delay)? IF so what is it?

[Johnny_9]

what is ta and tw?

[Hondata]

Air temperature and water (coolant) temperature. Honda used TA and TW for OBDI, then switched to IAT and ECT abbreviations for OBDII.

[Johnny_9]

What conditions need to be satisfied before the LTFT is updated?

Is is STFT>25% for more than 10 seconds?

[Johnny_9]

Does the post start enrichment period impact when closed loop starts?

[Hondata]

No

[Hondata]

I've put all your questions into one thread for easy lookup.

[Johnny_9]

How does the ECU know it is in idle? I.e.when to apply its idle functions

[Johnny_9]

how much air, in terms of percentage, can the IACV supply? +30% ?

are there any deadbands before the the IACV is allowed to intervene?

[Johnny_9]

It always operates, but the effect is reduced to zero by about 80 degrees C.

Can you share what is the programmed

Post "Start Fuel Adjustment" INJ correction % at each ECT band

for step 1, 2, 3?

Is it approx 22% fuel compensation at 31 Celsius for step 1?

[Johnny_9]

If you desire OBD1 over OBD2, you can convert the system back to its original self. An OBD1 jumper harness allows the on-board diagnostic system to perform like an OBD1. The process takes some time, but with a little patience you can get the job done.

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Escort Bayan

Wiring is OBD2a - I was wondering if the I could use a OBD2 connector and stock ECU and and use a scan tool to datalog.