Enrichment Issues when starting (warm)

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unreal-
 

Posts: 49
Joined: Mon Dec 30, 2013 5:46 pm

Enrichment Issues when starting (warm)

Post by unreal- »

Hi all

First off, the car:
- 96 240sx KA24DE with S14 OBD1 Nistune ECU
- GT2860RS
- 580cc Five0 Injectors
- new CTS, O2, TPS
- used Z32 MAF, 1.05-1.09v warm idle (low?)

Ive been dealing with a starting issue with the car for a while, and have tried various methods to try and fix it, to no avail.

Symptoms:

when hot, The car cranks over and idles fine, but the afrs go to 16.5-17.2 and fluctuate back and forth for about 30 seconds ---> 1 minute (sometimes longer), then slowly filters down to the low 14 range (14.1-14.5). Ive tried the following settings:
- changed the Engine Crank Offset to stock values (Nistune changed it when doing my tune to lower values, and my car was hard to start when hot, and required me to hold the gas a little) This allowed me to start the car without having to hold the throttle.

- Changed the after start enrich to stock values (they were a bit higher than the values that were previously in the box. I assume nistune changes these tables as well) This made my initial cold startup richer.

- Played around with the Cold/Warm Enrichment tables and managed to get it to start from the high 11's on a 10*c start, and slowly filtering to mid 14s at 50*c. But once it gets to the 50-60*c range it seems that the tables have no effect? i tried changing the values in this table to bigger increments but it didnt do anything.
This has been baffling me for a long time and ive changed every table in some way. Im going to try a few more crank enrich values that ive found on some tunes hosted from KA-T.org, but i dont believe the crank enrich table affects enrichment while running?

Thanks everyone, attached is the tune as of today
Attachments
jan 20.bin
tune as of jan 20
(64 KiB) Downloaded 132 times
unreal-
 

Posts: 49
Joined: Mon Dec 30, 2013 5:46 pm

Re: Enrichment Issues when starting (warm)

Post by unreal- »

Anyone?
Matt
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Re: Enrichment Issues when starting (warm)

Post by Matt »

Sorry for the delay

Crank enrich vs temp - will adjust your injection time during cranking only (so only when start switch is on). This table looks fine
Crank engine off set (vs rpm) - adjusting fueling during crank based on rpm. Agreed leave as stock

After start enrich - for a period of about 5 seconds this table is used to add a post crank amount of fuel. The amount decays over the 5 seconds until engine is running

After this the cold/warm crank tables are used. Look at the temperature where the problem is occurring and then adjust both of the tables (you can right click and copy to partner)

Other issue which may be causing this is your k constant is 440 compared to stock 257. When I do the resizing of Z32 and 580CC injectors I get K constant around 228 (which is close to stock). Yours is sitting at over double this value which makes me think you have something else wrong to be adding almost double the fuel.

Check your fuel pressure/fuel pump since these K changes plus your VE map alterations seem to be masking another problem. Also try another good known working Z32 MAF
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