13b cold start issues

[Daniel Timms]

Hey all

Ive recently had my 13b rx7 tuned but it does not like cold starting. 

It is a 13b-rew bridgeported, single turbo, 4x 1680cc injectors running link G4 RX

It takes a long time cranking it over before it fires into life from dead cold, and once its running it is sitting very low in the revs without any additional throttle from the driver. Once it is hot it will idle at about 1900-2000 rpm but during the cold start it barely reaches that and normally sits at around 1000rpm which sometimes can cause it to stall. 

Does anyone have a good cold starting tune or can someone take a look at my file and make some adjustments for me?

 

Thanks in advance

Keith Stewart tune 18psi 340kw.pcl

[r32skizzzaaa]

Do you have a idle control valve or cold start valve

 

[Daniel Timms]

No doesnt have anything like that

[Scott]

Looking at your base-map you don't have an idle solenoid. I would recommend adding one, as the ECU will then be able to control the air bypassing the throttle plate based on the current engine coolant temperature.

[Daniel Timms]

Thanks Scott I will track one down and give it a go. 

Do the cold start settings look okay to you?

[r32skizzzaaa]

increasing the cold start fuel enrichment up by 10s help as would give a lot more fuel to help fire up? can't see the map. I did this on my engine and helped a lot. Do you know the Afr from o2 sensor while cranking?

[Scott]

r32skizzzaaa is right, you could try and increase the crank hold time, or post start hold time. Your cold start settings are different to what we use in our RX7 plug-in ECU, but not vastly different.

I would recommend talking to your tuner, or if you want to do it yourself you will need to monitor the AFR/Lambda during engine warm up and then adjust as needed.

Edited February 11, 2016 by Scott

[Daniel Timms]

AFR is sitting at 12 during cold start. 

[Scott]

It may be that the engine needs more air-flow. Does it help if you hold the throttle open slightly during starting? If yes then try and adjust the throttle plate stop. If this makes the engine rev too high once it is up to temperature then you will need to look at adding an idle solenoid.