---===The Official MAFT-Pro Thread===---

[TurboBob]

Originally Posted by 3000GT MR

i cant post logs because my computers broken and i have to borrow this 1 to go online. when i get mine back i will. my logger missed fuel cut off it went from 5700 to 5969rpm and fuel cut off was around 5800 and thats when i let off the gas. As you can see my throttle was still shutting at 5969 hence the 14%tps ...but at 1 given moment according to my logger:
at 94%tps 5200rpm im at 1283hz 89%idc 37*adv. .98V at 100%O2 trim.
at 94%tps 5719rpm im at 1289hz 87%idc 38*adv. .98V at 100%O2 trim
at14%tps 5969rpm im at 1164hz 14%idc 40*adv. .96V at 102% O2 trim.

i richened it up a bit for this log to see if i could hit fuel cut off earlier but nothing changed. i've only done it when its hot. i dont like flooring my car when its cold. my car sounds like as if i was giving it gas and turning the key off at the same time. Thats all i can think of



after a while they all read High-72 med-72 low-73 my O2 trim at idle goes from 50ish to 150ish at any giving time. At 1 red light it will be between 123-150 and the next light it will be 50-80. always fluctuating. i've seen it as low as 43.. accoring to my wideband its been as lean as 19.5 and as rich as 10. my car is best at cruise. it runs great. stays right around 15.1-15.5 depending on rpm. it accelerates pretty good and smooth.


thanks for your help guys!
-Chris

If you are hitting fuel cut the injector pulsewidth will drop to 0. But at that dutycycle, it should not. What are you logging with?

[3000GT MR]

Originally Posted by TurboBob

If you are hitting fuel cut the injector pulsewidth will drop to 0. But at that dutycycle, it should not. What are you logging with?

yea you do have a good point i should have known. ill log IPW tonight on my way to work and ill post my results when i get to work. Im logging with Shiver's hybrid datalogger.

also would thoes reostats you answered about earlier affect anything?

Chris

[mightymoose]

wanted to be more specific, power is coming form a 12V switched source, the ground is going to the block.

The unit as well as the LC-1 are new, I even replaced the wideband thinking it was bad. No change, Car has been running great then all of a sudden this happens. I am also using a the recommended heat sink bung(everything facing the correct direction, etc)

recalibrated with no change.

anytime the AC, heater, etc is on, the LED will blink either continuously and now getting an error code of 4.
this also happens while pulling a hill in 1-2 gear.

any thoughts?

thanks
James G

[Rogue_Ant]

Have you tried a different switched 12v source?


-Rogue

[mightymoose]

will try that later on today, still thinking its the ground as oppossed to the 12V-- the LED always remains on or blinking, never off.. but will double check connections today and/or move 12V locations

[mightymoose]

switched 12V sources,, still not working properly. On the way home tonite I hauled absolute a$$ but intermediately the problem would occur,,usually climbing hills under mid load, the MAFT stops displaying any signal from the LC-1 that or it reads like 8.7 or something(even though its not really)

I tried recalibrating the control unit itself as well as the o2 sensor.. to recalibrate the heater unit, you just leave it on for 2 mins right?

anyway, no change, I can however, put it in neutral, high rev the engine , and work past the the wideband cutting off--could a fouled plug cause this also??

James G

[UCSB VR4]

I've decided to downgrade the size of my injectors from 720cc to 550cc or 580cc. This is mainly in an effort to help tuning, and prevent knock/timing issues.

Current tuning issues include:
- random rich conditions at idle (might go away with smaller injectors)
- extreme lean conditions when revving in neutral, but rich (CF -10+) when cruising despite similar MP and RPM values (i don't think this will go away with smaller injectors, but it might make it more manageable)

I'm looking for advice on whether I should go 550cc or 580cc with my current application (see sig below)??? I've always been told that 720s are too big for me and seems to be the root of many problems.

Future upgrades may include SMICs and 1-piece CFDS.

Advice please...

Thanks,
Jeff

[Rogue_Ant]

Jeff,
Do you have an adjustable FPR? If so you can drop pressure, and it will make the injectors act 'smaller'.
Even with 750 injectors I didn't have the issues that you're having.. lets see if we can figure out whats going on before you switch.

You have a PM.


-Rogue

[EastWingedBeast]

Originally Posted by UCSB VR4

I've decided to downgrade the size of my injectors from 720cc to 550cc or 580cc. This is mainly in an effort to help tuning, and prevent knock/timing issues.

Current tuning issues include:
- random rich conditions at idle (might go away with smaller injectors)
- extreme lean conditions when revving in neutral, but rich (CF -10+) when cruising despite similar MP and RPM values (i don't think this will go away with smaller injectors, but it might make it more manageable)

I'm looking for advice on whether I should go 550cc or 580cc with my current application (see sig below)??? I've always been told that 720s are too big for me and seems to be the root of many problems.

Future upgrades may include SMICs and 1-piece CFDS.

Advice please...

Thanks,
Jeff

Remember, free rev mixture should be lean. My data indicates 16.4AFR or more (19.8AFR). Thats acceptable. Set your cruise mixture first. Add some fuel to sort out idle, and put up with the rest.

[Rogue_Ant]

Originally Posted by EastWingedBeast

Remember, free rev mixture should be lean. My data indicates 16.4AFR or more (19.8AFR). Thats acceptable. Set your cruise mixture first. Add some fuel to sort out idle, and put up with the rest.

Free rev can be tuned. Most likely you will have to dive into the VE table.


-Rogue