Help needed please! FD rx7 cranking tables and warm up

[Myrotarylife]

Hello all,

I’m trying to ultimately save a huge amount of work in cleaning set after set of spark plugs....

Does anyone have some good table values for  the crank and warm up fuel tables?

I did manage to get the car started with the factory values but the closed loop lambda setting was what was ultimately keeping it running.

now I want to tune the idle and off load cells before hitting the dyno. All that is irrelevant of course if I get one start and then have to change the plugs.  

 

mods are:

Big street ports intake and exhaust 

Bosch 1000cc pri 1600cc sec

3bar fuel pressure

direct fire AEM Ign1a coils  

Borg Warner 91/80 turbo 

 

thanks in advance guys and gals  

Charlie.

 

 

[Adamw]

Im pretty sure the FD base map is from Link's FD test car that they have had for many years, so most of it should be pretty close.  You generally cant tune cold start well until the main fuel table is tuned as much of it is influenced by the main table.  You should really only need to adjust the master fuel to get it somewhere close.  

[Myrotarylife]

looking at the initial base map the numbers made sense to start with so I agree they may not have needed adjusting too much with the master fuel table also sat in its original base map values. 
 

I have however double the injector VE in the fuel table at idle to achieve an accurate and well controlled AFR. 
 

maybe I should try the base map values divided by exactly 50% as I have doubled the injector duty cycle values. 
 

 

[Brad Burnett]

What fuel equation are you running, Traditional or Modelled?

What Adam was saying was, from the base calibration, you should have only needed to adjust the Master fuel value in the fuel setup tab if in traditional mode.  If youre running the modelled equation, you would adjust the fuel injector size value in the injector setup tab.

Doing this would have got you running fairly close without the need to touch the values in the main fuel table.

Pending how far along you are with the tuning, maybe take a step back and start from square one to reduce the amount of plugs you need to buy? 

[Myrotarylife]

Hi Brad,

so I’m running modelled. I have set the injectors to 1000cc and at 3bar base pressure fuel. 
 

I have set the secondaries at a ratio of 1.65 too. 
 

Are you saying the algorithm, once the above values are applied, adjusts the warm up and crank values as a ratio so the base values shouldn’t really need touching?

 

if so I’ll do exactly as you said and go back to the base map with the adjustment for my setup inputs and outputs etc and try again.

I did however once I got it started previously have to double the injector VE value to achieve perfect idle and AFR values. I assume this is due to the doubling in size of my intake ports.

Thanks again for your help. I’ll let you know how it goes.

 

 

 

 
 

 

[Brad Burnett]

Thats not what im saying.  

The warmup and crank enrichment values are percentages applied to the main fuel table.

As Adam said, you will really dial these in after the main fuel table has been fully calibrated.  

But adjusting the injector scaling initially will get you in the ballpark.  

For Injector scaling, I hardly ever have them exactly set to what they are said to be.  I adjust the value to get the outcome i want while keeping the fuel table within a usable range(in modelled mode the max fuel table value is 150.)  If you find that you are maxing out the fuel table, you can scale both the injector size and the fuel table by the same percentage to get more resolution.

When you say you have to double the "injector VE" value, are you refering to the value in the main fuel table?

[Myrotarylife]

Hi Brad,

Yes, I am adjusting the main Fuel table. When I did get it running and up to temp I adjusted the values in the Main fuel table 1. These values ended up being double the initial map.

So if this is the case, because I doubled the fuel table cells I should in theory divide the warm up and crank tables by 50% to balance out and give me the same injection volume I had when I initially got it running on lower Fuel table values.

[Adamw]

If you have changed to modelled mode then you will really have to start from scratch with the warmup and cranking enrichments, at least the warmup will be very different. Usually if the charge temp approximation is reasonably close your warmup enrichment table will be mostly zeros.  Crank enrichment probably wont need to change much from the base settings..

[Myrotarylife]

Thanks Adam, I am going to have a play with this today with a fresh set of plugs and see how I get on.

[Myrotarylife]

Just a bit of an update. 

I pulled a pile of fuel out of the warm up map and she started without issue at all. I then in increments increased each table cell as the ECT increased, effectively mapping the ECT increase in the correction table. If anyone in the future is interested in what values I have used I would be happy to share.

Bottom line, it works a treat now and my plugs haven't fouled but like you said Adam, it was start low and then trial and error to get it right. I also managed to map the 0psi rev range and idle. Loving this ECU. 

Thanks for the input folks.