I'm currently mapping my GT40R setup, but have run in to a funny issue
with the fueling.

At 1bar, I have run in to a fueling issue. My inj duty is at 55% and
fuel pressure is holding strong. AFR at 1bar is going as high as mid
12s and I'm aiming for mid 11s. However, no matter how much fuel I
add to the base map or injector map, I can't richen the cells up. Now
I know I can flow more fuel, and I have been able to by using the
Injector Adjustment setting. At 3v (~1bar on my PIM scale) I can set
to 110, and the AFR's richens up appropriately, with Inj duty rising
in line also.

So if I can increase fuel using this setting, I'm stumped as to why I
can't raise is using the Inj and/or base map. I don't believe I
should have to use the Inj Adjust function at all should I?

Any idea's why this might be happening? I'm planning on mapping to
around 1.5bar tomorrow, so any help on this issue appreciated.

Cheers,
Lenny

 

A little late here so maybe you already resolved this... are you using the commander to tune or the datalogit? Based on your signature it looks like you have the fuel mods to support plenty of fuel.

If using the datalogit to tune, are you writing your settings to the PFC ("write all"), or have the auto update box checked? Or maybe the FPR vacuum line is not connected?

 

Thanks for the reply, have not resolved this yet. I'm using the datalogit for tuning, and have the autoupdate option checked.

I have watched the fuel pressure rise on a 1:1 ratio with boost, and it doesn't drop off, so pretty sure that it ok. It's a strange one, so will keep trying different things until I knock it out.

 

How do you have the fuel lines and FPR run? Do you have the fuel come into the primary rail then out to the secondary, then from there to the FPR, and back to the tank?

Or 2 lines from the tank with one line going to the primary, and one to the secondary, then both to the FPR, and return to the tank?

Either way is fine so long as the FPR is after the rails and not before the rails. I've seen this mistake made a few times.

I see no reason for the base map and INJ map not to increase the fuel. You're positive it's interacting with the PFC correct? You can log and see watches right?

Have you tried putting a very high amount of fuel in the maps to verify that it makes no change?

Finally if you have any exhaust leaks or if it's too rich and you have a lot of misfires it will read lean when it's really not. The o2 sensor reads the oxygen content rather then fuel content as some people think, so misfires or unburnt combustion will read lean when in fact it's just the extra oxygen being picked up from the unburnt mixture.

The only problem with any of my above recommendations is that you said using the inj adjustment the AFR does richen up, which is very odd. What version of FC edit are you running? and which box? Did you make sure you have the correct color datalogit box checked in the setup for the datalogit in FC edit?

 

Yeh, the FPR is after the rails (sequential rail setup). The FC Edit software shows all the monitors without any issue. In the lower load cells, we have been able to tune to afr without any problems, it's only when we start seeing 1bar.

I have one of the old beige datalogits, with the latest FC-edit software. The correct box is checked. We've mapped the car at actuator pressure (0.8bar) without any problems. It's definately strange knowing that we can affect fuel through the inj adjust PIM setting, but not the inj maps.

I've done a recalc on the current map, and made a few other changes based on Chuck's tuning notes. Will get on this soon.

Appreciate you taking the time to help.

 

can you post up your map? and i'll take a look and see if anything out of the ordinary stands out to me. It sounds like you have a handle on everything that i can think of so i'm not sure why you're having the issues you are.

What map sensor are you running? I assume you have the correct scale and offset used?

 

I'm running the GM 3 bar to the PFC, and the Apexi 3bar to the AVC-R. They read within 0.3bar of each other. The Apexi 3bar map sensor reads the same as the dyno.

I've attached the current map, and an untested map that I have done the recalc function on, and made other changes based on Chucks notes. The fuel map will look funny where we have just tried dumping max numbers in to see if AFR changes.

I think the primary injector size percentages in the current map are the result of flow testing the injectors, and sizing according to real life flow characteristics. I may change the updated map back to reflect those sizes.

 

I don't see anything that stands out as incorrect in your maps. Where does 1 bar land on your map? what P row? You're injector setup is fine and shouldn't make a difference in your problem if you changed it.

So you have tried adding a ridiculous amount of fuel to the map at 1 bar and still no change?

Your ignition split map doesn't look safe. Split should widen as boost goes up. I wouldn't go less then a 10 degree split after about 10 psi. I prefer to run about 12* split from 8 psi up.

This has nothing to do with the fuel problems, but it makes it even more dangerous if you're also running lean. For now i suggest you go with a 15* split from 0psi all the way to your highest boost. (p20) once you get your fuel problem sorted out you can tune your split for more power.

 

1bar = ~3v which lands around P15.. Yes, we tried maxing out the base map and inj map from P14 through P16 across the RPM range and it didn't show any HP or AFR changes.

Honestly, I haven't even looked at the ignition maps yet, wanted to get the AFR's in check first. I hadn't done a review of the current splits, so thanks for pointing that out. That ignition setup is from my parallel twins @ 1bar, from one of the few UK premier rotary tuners

 

that map is a mess, especially the timing. The fuel also is very lean. I would suggest starting with a stronger base map.

 

Appreciate your comments. All we have mapped at the moment is the power run cells of the map, so yes is is a mess. Until we get the fueling issue resolved, I'm really not going to start making the map look "pretty".

If you guys can point me torwards a decent GT40R based map, I'd be more than happy to use that as a base.

 

A couple comments here. I think you first should focus on driveability stuff (idle, cruise AFR's, tip-in), and that requires proper injector settings. Both those maps were pretty messed up in the whole settings 5 area. Next, your timing is screwy as people have said. Finally, go to the basemap tab and switch it from Base (msec) to INJ x Base (msec). You will notice that your fueling is falling off at 6000rpm, just like the map for stock twins. On my T04S setup (significantly smaller than a GT40) my fueling continued to 6800 rpm before it trailed off.

 

Hey, I'd love to be able to add more fuel to the top end of the map, but per my original post, it won't let me!!

I'm well aware that the map is no where near ready. None of which is relevant to the issue in the original post.

I appreciate everyones input, I do, but before anyone else wants to point out the obvious I'd like opinions on how to fix the issue regarding fuel cell changes beyond 1bar and the lack of impact on the AFR's vs InjAdjust PIM changes

 

That map sucks and the car will run like ***. email me and I will send you a good base map. jason@rx7store.net

 

Hey Jason, I already did, and you already have!

 

Did the map I send not help? After thinking about it I think I sent you one for 850 primaries and not 1000 , but I could be wrong

 

That's right, it was for 850's which I can adjust, but also looks to be setup for a 2bar map sensor? I haven't tried that map yet, waiting on the dyno to free up this week.