I went to the Rx7 store today to tune my car. started to do a full pull at 7000 rpm started to get real lean 12.8afr. Jason tried to get more fuel out of it but would not happen. The injector duty cycle would not change either stayed at 69.8 % would not move. The fuel pressure was holding at 59psi was not dropping. I told them I would take the car home and try to fix the problem. my finale numbers ended up turning out very well for the problems we had 15 psi 440hp 6800 rpm. has anyone experienced this?


fuel system consists of duel denso pumps, going to a fuel block to stock feed line to stock fuel filter. 1680 sec 850cc in milled primary rail. With this much fuel I should be good for over 500hp. It could be so many things. I just wanted to see if anyone had any ideas other than mine

 

What ecu?

 

power fc

 

If the injectors are setup correctly, and with your fuel pressure, more fuel should be allowed to be added.

The only thing that would prevent it, is if the fuel was maxed out in the fuel correction map and you were using the commander for adding fuel there.
You will then have to do the RECALC with the datalogit, and then start over again.

This is an assumption since you did not give us your final map or more pertinent information.

 

rx7 store was doing all the tuning.

 

That does not mean anything as it does not tell exactly how they did it!

 

They were using a lap top and datalogit software

 

how old is your fuel filter

kevin.

 

It is brand new changed and relocated it 2-3 months ago. what has me puzzled is that it held 59psi of fuel so the fuel would be their.

 

That does not means anything. The DL is only as good as the person using it!

It appears that you are oblivious to how to tune or make adjustments to the PFC even with the Commander. Go check out your Fuel Correction map and tell us what range of values are in P rows 12- 18 for N columns 10 - 20.

 

No I know exactly what you are saying what I am saying they were doing all the tuning so I don't know what was going on. I am going by what they told me I would check my commander but my fuel system is out of my car I will let you know in a few days. Thanks for the info

 

Something is fishy if the injector duty cycle would not change, it's not an issue with your fuel system, the issue is with your PFC. The PFC reports what it tells the injectors to do, not what the injector are actually doing. If the tuner added fuel in the PFC and it did not change the injector duty cycle then either Chuck is right or your PFC is hosed. I would swap in a known good PFC and load your map then try again.

 

That was what I was thinking may trying another pfc cause I am thinking something is wrong. I went through my whole fuel system yesterday and could not find nothing wrong. I don't think in was in the fuel system but I did want to check to make sure everything was good

 

N10 11 12 13 14 15 16 17 18 19 20

P12 94 94 100 100 100 100 100 100 100 100 100
P13 94 94 100 100 100 100 100 100 100 100 100
P14 100 100 100 100 100 100 100 100 100 100 100
P15 100 100 100 100 100 100 100 100 100 100 100
P16 105 105 105 105 114 116 117 117 117 117 117
P17 105 105 105 105 114 116 117 117 117 117 117
P18 105 105 105 105 114 116 117 117 117 117 117

 

Are these the wright correction values

 

100s mean that 100% of the fuel in the corresponding Base Fuel Map is being used.

117 mean 117% of the of the fuel in the corresponding Base Fuel Map is being used. Same as saying 17% more fuel was added to that cell.

149.6 is the most allowed by the software(DL). If more is needed, a RECALC has to be done first. This would take the 49.6% increase add it to the base map, then reset the 149.6 back to 100.

If the RX7 store tried to increase this amount with the commander or DL and your fuel system is working propery, and nothing happend; the PFC might be bad. But there are other places to add fuel to determine where the problem lies.

Two places in Settings 3 and One in Settings 5 also allow extra fuel with the DL.
Using the Commander is the Fuel/IGNITION screen.

It would not take long to determine if the problem is the PFC or not.

 

Can the fuel duty % setting, as displayed on the attached PFC Base map, be greater than 100%? Recalc has been performed, so the INJ map is set to all 1's. As you can see in the lower right corner I have fuel duty % set to values greater then 100%, will that work? Should I force them back to 100%, since I am past the max torque?

 

For The Love Of God,

change the stock feed line and the stock fuel filter. They are not enough.

I bet that at full throttle going from 2-3-4 gear, at the shifts, you get lean-outs and probably high knock readings.

 

You can not log or run over 100% duty cycle as that would be imposible.
Imposible like stupid people who say "Doh bro, I gave 110%!".

Now it can be over 100% if it is a comparison of original to current values.

Time for you to join the real world and use "Base (msec)".

 

Ok, I do live in the real real world, and I do understand the concept of not being to run an injector 110% of the time, unless of course, the manufacture designed it with 10% headroom.... but thats not the point here.

Clarifing my question, after doing AF tunning to make relitive adjustments to the INJ map, and then running recalc, if I go to the base map, which is usually in msec mode, and switch it to the fuel duty % mode (mode switch in lower right corner) you can see calculated figures over 100% in the lower right corner.... The PFC lets this happen, shoud I force thoes back to 100%?

Another way to ask the same question is: can I run the inj msec times shown in fileds n16,p17 to n20,p20 (see attached).. with stock injectors?

 

I'm adding a tme domain look at measured results, my prior posts were PFC control settings, see attched

 

knock values were mentioned earlier in this thread. unfortunetely my knock value has been getting slightly higher and higher and has actually hit 100 on the pfc...so, am I just not getting enough fuel now or what?

 

(1)Colder air = more power which may = higher knock if tuned during hot summer.
This can be caused by too aggressive timing.
(2)Air Temp vs Injector Table not properly set up.
(3)Fuel pump going bad causing a drop in pressure.
(4)Dirty fuel filter dropping pressure.

 

well also i've been having a rich gas smell coming from the engine bay. i mean i can really smell the fuel now...maybe a leaky injector, not sure yet