Cold Weather = Rough Starts Need advice: 2JZGE VVTI

[Darrow]

Need help with the cold starts in the morning. Warm starts are fine and my FURYX was put in during spring time so I have not set up my startups for colder temperatures. I think that is the problem. Could be my whole setup for initial startup is off a bit. Looking for advice on any changes. Logs and Setup files are in the google drive link. Thanks in advance.

https://drive.google.com/drive/folders/12wrTYT-x6jV4RwTuiOMFSz-O--KEJiXH?usp=sharing

PC Datalog - 2023-10-25 6_28_08 am Key only Morning.llgx 2023-10-25.pclx PC Datalog - 2023-10-25 4_20_27 pm Key only Evening.llgx

Edited October 25, 2023 by Darrow
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[Adamw]

You dont have any fuel pressure until about 0.3s after it starts cranking so that wont be helping, this likely means you wont be getting any pre-crank prime or first crank prime.  So fitting a check valve will probably help.  Or you could zero out pre-crank prime to get rid of the variability of that and instead just rely on crank enrichment.  

If you fit a check valve then you could change pre-crank prime to start pos for a better result.   Your pre-crank prime values will likely need to be about 1/4 of their current values and the first crank prime would typically be more like 50-150%.  

[Darrow]

Adam,

It is a return fuel system. For those starts I waited until the CANLAM gave a reading and then started the car. I think the fuel system lowered pressure in that time. I did add a bit of fuel based on another recommendation and that helped a bit. 

I had an issue with being too rich before and I, obvious now, went too far leaning it out.

[Adamw]

15 minutes ago, Darrow said:

It is a return fuel system. For those starts I waited until the CANLAM gave a reading and then started the car. I think the fuel system lowered pressure in that time.

It doesnt matter, it should hold pressure for at least an hour after it has primed.  Some aftermarket pumps have the check valve removed to increase flow so if you are losing pressure quickly it usually means there is no check valve in the pump.  This causes not only cold start issues but also "vapour lock" when hot.  You can get inline check valves to fit elsewhere if the pump doesnt have one.  

[Darrow]

Adam,

Appreciate the input.

I do hear a strange sound from time to time on startups which are usually after quick stops, like for gas or convenience store stop. It kind of sounds like air going through the fuel pressure regulator before the fuel gets to it and the sound stops. Kinda like a very rapid chatter-y higher pitch whine for a second or two.

Working with a 40 year old stock Toyota fuel pump. I will add that to the to do list. I wish the list would get shorter not longer.

Thanks.

[0x33]

try this. wasnt sure on your injectors, but see if better/worse

newstart.pclx

[Darrow]

Thank you I will try. I noticed a lot of change for the crank/post crank fueling. Are there any other big changes?