I don’t know what I am looking for; maybe some guidance, help troubleshooting some small issues, or maybe just some reassurance that it’s just normal for built RX-7’s. I have a couple concerns with the overall functioning of the RX-7. I have read Wargasm Power FC.pdf at least 10 times; and Acceleration Enrichment Finally Fixed-Final.docx once. My Power FC/FC-edit pretty much mirrors the writings and recommendations found in Wargasm Power FC.pdf. I'm not looking for power or big numbers or roll racing Mustangs/Camaros on the highway. I'll sacrifice HP, torque and gas mileage for reliability. I’m happy with 10 - 12 PSI of boost all day. The car runs and drives great, minus a few bugs.

I have a pretty good understanding of the FC-edit program and a general working knowledge of tuning. I'm looking for a second pair of eyes to look over my FC-edit menus and see if I overlooked anything or typed a bad value somewhere in one of the fields and to see if anyone has any recommendation for the issues below:

Issue 1: Normal driving on the highway; cruising in 5th gear between 60 - 65 MPH (or and cruising speed). If the road starts to incline slightly just to contour the land. I get an intermittent "hiccip" in the throttle as the motor gets a little load on it (still in vacuum). Might happen once, maybe twice; then normal. No real pattern or frequency.

Issue 2: Coming to a stop at a traffic light/stop sign. Once I push the clutch in and come to a complete stop. The engine is idling between 2000 - 2500 RPM’s for about 5 to 7 seconds before setting down to a smooth 1000 RPM range. Happens 95% of the time; AFR’s are steady.

Issue 3: Rarely, when I stop at a traffic light. My idle and AFR’s are all over the place. Idle fluctuates between 1000 to 2500 and the ARFs are all over the place for 11.5 to 16.5 and everything in between. Almost like the ECU is having a small heart attack. I just burp the throttle and it corrects itself. Normal idle again.

Issue 4: Normal cruising in any gear; not on the throttle but not off the throttle either and not under load. That steady sweet spot to maintain a constant speed on a flat surface. I have this small cavitation/bucking feeling in the motor where it doesn't know what to do.

All of my AFR’s under vacuum are in the range of 11.5 to 12.5 with my idle AFR sitting at 12 (+/-). I feel the issue could be with either the Inj vs Accel TPS or Accelerate Inj (both confuse me a little) or some other setting I have overlooked.

95 FD Street Port
T04Z
ING-A1



IngMap

IglMap

IgtMap

BaseMap

Setting 1

Setting 2

Setting 3

Setting 4

Setting 5

 

a few questions before addressing your issues. your answers will provide context and will allow for a proper answer or suggestion.....

1: did you factory reset the power fc before starting to tune and if so how much driving have you done since then?

2: what was the reason for your option 4 pim scaling? was that was needed to get the map reading to read 0.00 with key on? your map scaling could be a lot better. i think dale has a thread on it. your scaling really doesnt need to go down to 400rpm and you have an 8250 rev limit but your scale stops at 8000.

3: your injector settings are way off for the sizes you have there? 715cc? what are those?

4: your dwell times for the coils your using can be longer. i imagine those are the factory pfc dwell times. youre not getting the most of the upgrade with what you have there. sakebomb has a recommended setting you should try

5: have you checked your tps calibration? try driving with the sensor check up on the commander and whenever you get those little blips or burps, look over at yout VTA values. see if they go to max value.

 

FDAUTO,

Its a long story, but here is the short version. The motor was completely rebuilt by a reputable RX7 shop in New Jersey. They did great work, but it was during COVID (2020). They rebuilt the motor, however, didn't have the manpower or the time to put on the break-in miles before tuning (COVID was the reason). They had me pick up the car to put the break-in miles on it and then later wanted me to bring it back for tuning. Life happens, had to deploy for 3 months plus a few 2 week deployments and general life happening between then and now. Fast-forward to today and I might have 1600 miles on it since the rebuild. Averaging 50 - 100 miles every month doing cars and coffee when the weather is nice. The told me they installed a break-in tune. I hate to assume, but I can only assume they did the right thing since I trust they knew what they were doing.

Q1: Ill assume the shop did a factory reset and I only have about 1600 driving miles on this engine. Running 93 plus pre-mix.

Q2: The PIM scaling was already set when I got the car back. So was the scaling for the RPM's.

Q3: again, I hate to assume and looking at my paperwork from the shop. It just reads IRP Competition Fuel System. It doesn't state the injector size. Ill assume they put the correct value in.

Q4: I know nothing about the dwell times for the coils and how those numbers were entered.

Q5: I have not checked my TPS calibration.

This is all the information I have; therefore, I am working off the assumption that everything was tested and loaded. If starting over is the answer, so be it. With tuning that is.

 

Understood.... disregard all tune related questions then.

so....... probably not the answer you want but either going back to that shop or getting a tune from scratch from someone are going to be your options here. the IRP website is down and seems to have been removed completely so i cant check and see what exactly the fuel kit entails to at least help with the injector settings. your equipment will need to be verified before moving forward with adjustments to the tune.

to address your original post though.... everything you have going on can be attributed to the tune. not saying they 100% are because of the tune but they absolutely CAN be associated. in a situation like this because the tune is likely to be the cause of your woes, it has to be eliminated as a possibility before further troubleshooting. if you try and troubleshoot around it, you may just be chasing your tail. you don't necessarily need a complete tune but having someone go through the map and make adjustments to get what you have going on to stop would be advised. depending on how the car responds will determine if you have an issue outside of changing values in the map but based on what i see and what you're saying, my bet is it just needs tuning.

 

FDAUTO,

Thank you for the insight. You are right, not really what I wanted to hear, but expected it. It sounds like complaining on my part; but It's just a major ordeal to get everything lined up to get it to the shop. I too tried looking at the IRP website for the injector info. With the website down, it worries me that rotary tuners are few and far between. Perhaps as we set in for fall/winter, I can find the time to take it back up. I just have times where I lose interest and put the car on the back burner. Thank you again, I just needed someone else to tell me what I already knew.

 

i agree with FD Auto. car and map are kind of question marks...

however for the idle stuff, 2 and 3, you can log the BAC/ISC duty, its the ??? one. at idle it needs to be over 150 and less than i think 300? or the PFC won't be able to control it.
you can adjust the AAS screw to get the number in range. it should help a lot.

i would also lower the redline back to 8100

 

J9FD3S,

Ill make the changes to the redline now. Can you refresh my memory on how to log the BAC/ISC and what number are you referring to with you say 150 and lass the 300? Never logged anything other than AFRs. Does this log validate anything. First one is with the engine off, key on and the second is engine on with about 10 minutes of driving.

Ignition on

Engine on

 

if you log advanced, and the Aux for the wideband, its like this. you can do a map watch as well

 

When going to larger injectors you need to have their lag tables and know what your base fuel pressure is. If you run too low of a base fuel pressure there is a chance that the lag table does not include your value.
Base fuel pressure also affects injector flow rates. Thus you need all of this to properly setup Settings 5 injector values. The base fuel pressure fuel flow rate for the injectors is used for the S5 values.
Thus a EV14 2000 injector can flow a wide range depending on base fuel pressure. See attachment.
When you go to larger injectors such as yours, the fuel temperature sensor is also removed thus this accounts for the 4.98 voltage.
You need to find someone locally who not only has the PFC software but the FC-Tweak software to properly set up you map.

If you e-mail you map to me I can do this for you. To be safer and more accurate I would need to know which injectors and their sizes (i can figure this out if not available) and your base full pressure.
Some lag table go down to 40 psi but others have a minimum of 43.5. You should have an adjustable regulator and I suggest set your base pressure to 43.5psi for easier setup.
All you need is a low pressure adjustable air supply and an accurate air pressure gauge to pressure you fuel pressure regulator.
Include a list of all engine mods.

cewrx7r1@yahoo.com

 

I did forgot to list a bit of additional data in my previous post.
When injectors are tested for lag, it is done with specialized equipment with a great power supply using wiring that is short thus minimizing lag.
This was mentioned by Xavier when he was testing his FC-Tweak .
The Mazda smaller and longer wiring increases lag.

My car was perfectly tuned with the stock 550 primaries but when I converted to the newer EV14 550 injectors, the car was lean on the low end even though I set up the lag table correctly.
I had to adjust the primary lag correction from 0 to 0.25 to fix the problem without having to AFR tune that area of the map.