Sale ends todayGet 30% off any course (excluding packages)

Ends in --- --- ---

Tuning afr and idle Unstable

Understanding AFR

Forum Posts



Tech Articles

Discussion and questions related to the course Understanding AFR

= Resolved threads


Hello my friend,

i have add my map and a log.

the points we need to tune is:

1. on 1700-2000rpm when i let go the throttle there is a spark and the wideband goes crazy

and when i back on throttle the 1st second is a kick and then it goes OK.

i can see it on the log

2.idle rpm

now it is on 850rpm, it is should be 800rpm

bat when i set 800rpm it goes 100rpm low and high

3.when i let go the throttle the wideband is rich in any gear or speed the RPM goes low to 200-300RPM or the engine goes off

it need to stay on 800RPM when i let off the throttle

4.as i saw on the wideband when i go off the throttle for 1sec is rich and when i go on the throttle at the 1st second is lean.

if you need any more logs let me know,

thanks, Tomer.

It doesn't appear that your log file or map are included. Can you also let us know what ECU you're running, what the engine is, and what modifications it has for some context please.

I have a peugeot 106 gti tu5jp4 engine

Ecu elite 1000.

I switched to camshft for catcam 743 I grew injectors for clio 47mm 12 ohm impedence 250cc/min Pico injectors and porting in the throttle.

Map and log file attachments.

If the file did not upload can you give me your email and I will send there?

Thank you and good day.

Attached Files

I've had a look through your map and your log file (which is really too short to be overly useful). I haven't dealt with that particular engine and I know nothing about the cam you're running. My suspicion, without having the cam specs, is that you may be trying to make the engine idle a little too low. Is there a reason why you can't let it idle at 850 if it's happy to idle there? Your rpm drop is likely a combination of the overly rich condition, and possibly your base idle control settings. You want to make sure that the base idle duty is high enough to catch the rpm before closed loop control begins. I'd suggest that your VE table may need to be reduced in the over run areas to get the AFR on target. Once the VE is correct in steady state you may also need to use more transient 'disenrich'.

Okay I'll change idle to 850rpm. How do you want the recording file to see what exactly to do with the vehicle during recording so you can help me with the other problems?

Thank you and good day

Hello, I have added a map, file and data log.

I have some problems

1) open the af throttle throttle per second mainly in low columns

2) Close the afr throttle is rich for a second

3) Unstable idle

4) After decel the fuel returns, the engine kicks as the throttle opens and closes quickly

5) Holding a fixed throttle that is unstable and also the motor

6)Back to idle

If you need more logs, more blogging parameters, just say so and I will add.

Thank you very much and have a good day

Attached Files

Hi Tomer, it appears you don't have rpm logged in either of those files which makes it hard really to learn much from them unfortunately. If you add in rpm and make another log file I'll take a look for you. You do seem to have a pretty unstable MAP signal but this could be a result, not a cause. Are you using the onboard MAP sensor or an external sensor?

Hi andre,

I use external sensor, The original sensor of the vehicle.

Regarding rpm I will upload a new file, do you want to write down which parameters are important to you and I will only record them?

Thank you and good day.

Hello Andre,

I have attached a file with RPM.

Thank you and good day.

Attached Files

Hi Tomer, I've just had a look at your log file '106GTI2DATA' and the data in this log looks pretty stable to me. The other log file shows a couple of weird fluctuations in the rpm and you can also see this in the MAP trace. Each instance seems to coincide with some erratic activity from your closed loop idle output so it's possible that your closed loop idle control gains are the issue here. i'd start by disabling closed loop idle and just use a fixed duty cycle and see if that settles your idle. If it does then I'd reintroduce your closed loop control and halve the gains and test the response.

Okay I'll try this and update.

I think there is also a dead time problem of the injectors I am also testing this, do you have an idea for testing the dead time without the manufacturer's data?

Thanks so much for all the help.

We usually reply within 12hrs (often sooner)

Need Help?

Need help choosing a course?

Experiencing website difficulties?

Or need to contact us for any other reason?