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R32 GTR - RB26 - Cold Start

Posted: Thu Mar 30, 2017 7:15 pm
by grok000
Hi,

I've managed to tune the ecu while the engine was warm from previous ecu up until boost starts (WBC2), i've set injector dead times and size. I've used the standard R32GTR-VE map provided from Haltech.

But now i'm trying to get the cold start to work but i keep fouling the plugs and the car wont start at all now with the haltech but will start with the power fc but has a bad misfire (fouled). Initially the car started and then stalled after 30 seconds and had a massive flatspot.

Where is the best spot to start with the getting cold start right? Post start correction and zero throttle?

Thanks for you help

George

Re: R32 GTR - RB26 - Cold Start

Posted: Wed Apr 05, 2017 3:40 pm
by HaltechMatthew
Leaking injectors will cause similar issues, but if it is definitely not proceed below.

Prime Pulse is the first shot of fuel. If this is correct the engine will start. Sounds like yours is set way too high if it is not starting. This is raw injection time and will need to be dialled in to suit injector flow.

If it does not start for whatever reason, the Cranking Inj Time table is used when the RPM is below the Cranking RPM. If Primer is correct you wont need this table. Also in raw injection time.

After it starts the following are used:

Fuel Base is always used. Dont adjust this because you already set it when hot.
Post Start Enrich provides extra fuel to prevent starting then stalling. Too little it will stall, too much it will foul. Usually not the problem for what you are reporting unless the numbers are crazy high.
Cool Temp Corr is a correction against coolant temp. Adjust this after the post start is done.

Re: R32 GTR - RB26 - Cold Start

Posted: Thu Jun 08, 2017 7:35 pm
by grok000
thanks matt for the reply, followed you post and it starts and runs nicely now. Just fine tuning with cold weather now.

I also performed a injector test to make sure they weren't leaking.

The only issue i have now is that the car has pop/stumble at idle when i have the afr 's 12.5 or higher. If i add fuel and have it sitting with an AFR of 11.5-12, its rock solid, anything above that and it jumps around. I've noticed the front bank (1-3) is the erratic one. I've attached a datalog.

The injectors are denso 720cc.

What do you think?

Thanks

George

Re: R32 GTR - RB26 - Cold Start

Posted: Fri Jun 09, 2017 1:01 pm
by HaltechMatthew
I think your injectors are terrible. Poor atomisation is why you need to run it so rich.

Re: R32 GTR - RB26 - Cold Start

Posted: Wed Jun 14, 2017 9:14 pm
by grok000
thanks for the tip. Is this typical of these injectors or do i just have a terrible set?

Any recommendation for better injectors?

Re: R32 GTR - RB26 - Cold Start

Posted: Thu Jun 15, 2017 2:45 pm
by HaltechMatthew
Go for as modern an injector as you can is always the answer. The common Bosch/ID 1000s are always a crowd favourite for high flow with excellent atomisation. These will normally idle perfectly on 14.7:1 with those engines.

Re: R32 GTR - RB26 - Cold Start

Posted: Sun Jun 18, 2017 9:11 pm
by grok000
thanks matthew, do you think the ID are worth the extra money over the bosch? the internet has many stories regarding Bosch items not being as good??

thanks

Re: R32 GTR - RB26 - Cold Start

Posted: Wed Jun 21, 2017 4:52 pm
by keet45
Bosch is worth trying. A couple of guys I know have them and never heard any issue.