RB26 Cold start enrichment tables...

[r33lew]

So i have my car to the point it actually starts now, but dies straight away, i will attach a log of it doing so...

its 5 degrees here and getting colder.. 

my main question is, do the cold start enrichment tables completely over ride the main table?

the car bursts into life like its going to run just fine then dies..

newest start up.llgx

[aerace_fab]

Attach your tune file as well.

first thing you need to address is the post start enrichment.

[r33lew]

1 hour ago, aerace_fab said:

Attach your tune file as well.

first thing you need to address is the post start enrichment.

 

R33GTR NEW.pclx

[Adamw]

Double the values in your fuel table as a start, as we mentioned earlier the fuel table you have is not suitable for modelled mode.  

Also something a bit odd with your fuel pressure, it is sitting at zero until you start cranking so you wont get any pre-crank prime and crank enrichment will be effected.

[r33lew]

11 hours ago, Adamw said:

Double the values in your fuel table as a start, as we mentioned earlier the fuel table you have is not suitable for modelled mode.  

Also something a bit odd with your fuel pressure, it is sitting at zero until you start cranking so you wont get any pre-crank prime and crank enrichment will be effected.

My fuel pressure drops off when my fuel pump isnt running, so raises to 45psi when i key on, and fuel pump primes, then drops off until i crank, does this sound normal? 

[r33lew]

On 12/23/2021 at 11:36 PM, Adamw said:

Double the values in your fuel table as a start, as we mentioned earlier the fuel table you have is not suitable for modelled mode.  

Also something a bit odd with your fuel pressure, it is sitting at zero until you start cranking so you wont get any pre-crank prime and crank enrichment will be effected.

Also  i tried to double my fuel table and it makes the symptoms of suspected flooding worse.

[Adamw]

On 12/24/2021 at 11:53 PM, r33lew said:

My fuel pressure drops off when my fuel pump isnt running, so raises to 45psi when i key on, and fuel pump primes, then drops off until i crank, does this sound normal? 

Not really, most pumps have a check valve so pressure remains after the pump shuts off.  

 

10 hours ago, r33lew said:

Also  i tried to double my fuel table and it makes the symptoms of suspected flooding worse.

What makes you think it is flooding?  Are the plugs wet?  

Can you temporarily set fuel system type to "MAP Referenced" so that you dont get the big increase in inj PW when the rail pressure is low as a test.

[r33lew]

39 minutes ago, Adamw said:

Not really, most pumps have a check valve so pressure remains after the pump shuts off.  

 

What makes you think it is flooding?  Are the plugs wet?  

Can you temporarily set fuel system type to "MAP Referenced" so that you dont get the big increase in inj PW when the rail pressure is low as a test.

Interesting, i did think when i first primed it, that it would hold pressure but, it only did whilst the pump was on. 

 

Ive tried it on a map referenced setting, and it was still the same, although this was a setting changed after many attempted starts as FP sensor.. maybe i could try clean the plugs and start from MAP referenced... can i ask what the benefits of FP sensor would be over MAP?

 

The reason i say flooding, is because...

If i clrean the plugs and bores, fire it up, it will burst into life, then cut out, and the the nect start up i try isnt as good, and they get worse and worse, i then switch the injectors off, turn it over whilst it pops and bangs and burns any unburnt fuel... once this stops, i swith injectors back on, and it fires good again for the first couple... so it feels to me like its too much fuel.

[Adamw]

10 hours ago, r33lew said:

can i ask what the benefits of FP sensor would be over MAP?

With the system type set to FP sensor the ecu will correct for changes in differential pressure - say for example your fuel filter blocks up and restricts flow, then the ecu will see the loss of pressure and open the injector for longer to try to inject the correct amount of fuel.  So it is a good strategy to have.  But my only thought in this case why I suggested a test with it turned off is because your fuel pressure is sitting at zero initially so the ecu is massively increasing the injector PW on initial crank until pressure builds.   

 

10 hours ago, r33lew said:

If i clrean the plugs and bores, fire it up, it will burst into life, then cut out, and the the nect start up i try isnt as good, and they get worse and worse, i then switch the injectors off, turn it over whilst it pops and bangs and burns any unburnt fuel... once this stops, i swith injectors back on, and it fires good again for the first couple... so it feels to me like its too much fuel.

A quick adjustment if you think it has too much or too little fuel is to change the engine capacity setting.  Halving the engine capacity will halve the amount of fuel injected.  Obviously this setting eventually needs to be set correctly, but you can use it as a crude adjustment to help troubleshoot whether you have too much or too little fuel.