Occasional problems starting the car after tuning the car

[hjkim483]

Ever since dyno-tuning my car this Monday, my car has refused to start two times. I had to rev it continuously while trying to engage the ignition and then it finally turned on. This happened once after I filled in gas at bp and once middle of last night.

Is it possible that the powerfc can cause this problem or could it be something that coincidentally went bad. How should I break the problem down?

Also, how do I know if I'm running rich or lean from the FC Commander?

Thanks,
Mike

[hjkim483]

Could it be that my idle is set too low at 850 rpms? My car idle is set to 850 but the actual rpm displayed on the FC commander is around 920 - 970 ish...

[00silverGTS6spd]

if you click the key over for a second before you start the car you'll be fine. mine does this too with the power fc in. mostly when the car has sat like overnight. No idea why it does it though.

[hjkim483]

ah... thanks alot!

[Jesse IL]

Originally posted by 00silverGTS6spd
if you click the key over for a second before you start the car you'll be fine. mine does this too with the power fc in. mostly when the car has sat like overnight. No idea why it does it though.
That never solved the problem with my car. Go into the temperature correction values for coolant and change them to slightly less enrichment for cold coolant temperatures. You can do that from the commander.

[00silverGTS6spd]

Originally posted by Jesse IL
That never solved the problem with my car. Go into the temperature correction values for coolant and change them to slightly less enrichment for cold coolant temperatures. You can do that from the commander.

thats a good idea too.

[hjkim483]

Could you provide a step by step way of doing this? I have yet to mess with the commander in fear of my lack of my experience.

[tofu]

I have this problem as well and i cant really pinpoint the cause of it...but i do have to say that when i use autostart from my compustar alarm it starts everytime....

[Torqued]

Originally posted by Jesse IL
That never solved the problem with my car. Go into the temperature correction values for coolant and change them to slightly less enrichment for cold coolant temperatures. You can do that from the commander.

I agree that the occasional problem may be related to a flooding condition. When the car finally catches it usually stumbles at first - just like a flooded engine.

Jesse, what are your wideband readings during the initial engine warm-up?

There are two ways we can correct this condition (assuming it is a flooded condition) using the PFC and after the A/F under normal operating conditions is set. You can adjust the temperature corrections - there is an air temp and a water temp correction factor. If the air temp outside is fairly warm then it makes it easier to adjust the water temp corrections - you can do this with a wideband sensor. Second thing is adjusting the cranking duration on the injectors. I'd do this after the water and air temperature corrections are done.

[2000GTSblack]

It is also possible that the engine may want a little more ignition retard on start-up. High compression motors are known for this. This cured that same prob on friend's rsx.

[Oli]

i've found changing the cranking delay helps the problem.

[Jesse IL]

Originally posted by Torqued
I agree that the occasional problem may be related to a flooding condition. When the car finally catches it usually stumbles at first - just like a flooded engine.

Jesse, what are your wideband readings during the initial engine warm-up?

There are two ways we can correct this condition (assuming it is a flooded condition) using the PFC and after the A/F under normal operating conditions is set. You can adjust the temperature corrections - there is an air temp and a water temp correction factor. If the air temp outside is fairly warm then it makes it easier to adjust the water temp corrections - you can do this with a wideband sensor. Second thing is adjusting the cranking duration on the injectors. I'd do this after the water and air temperature corrections are done.
Well, the UEGO takes a few seconds to initialize but here's what I see:

Stock ECU: car settles to stoich immediately, regardless of air and coolant temperatures. In general the car does not run any richer cold vs. hot

PFC: car is stoich, but then drifts richer. On a warmer day, cold engine, the car will idle around 13.5:1 when full cold. The worst i have ever seen was on a day this winter then we had temperatures around 5 F. First off, the UEGO is frozen and takes a few minutes to even work. Next, the car will idle in the low 11's and go off the scale rich as soon as you get on the gas. Even with the car fully hot, the car runs richer than it should with cold air temps. So basically both the coolant and air temp correction factors are off.

[hjkim483]

So it's got nothing to do with the cranking delay? How can we adjust the cooland and air temp from the FC Commander?

[Jesse IL]

You can only adjust coolant temp correction values from the Comander. Just scroll through the menus, you'll find it.

[Oli]

Originally posted by Jesse IL
You can only adjust coolant temp correction values from the Comander. Just scroll through the menus, you'll find it.

You can adjust the cranking delay on the commander as well. when your in the temp correction part press enter and it will switch to the cranking delay settings.


Originally posted by hjkim483
So it's got nothing to do with the cranking delay? How can we adjust the cooland and air temp from the FC Commander?

The cranking delay depends on how much fuel you want to run at and around idle as far as i know. Now my map is leaner I reduced the cranking delay to help cold starts. Once its right it works everytime.

[Torqued]

Originally posted by Jesse IL
Well, the UEGO takes a few seconds to initialize but here's what I see:

Stock ECU: car settles to stoich immediately, regardless of air and coolant temperatures. In general the car does not run any richer cold vs. hot

PFC: car is stoich, but then drifts richer. On a warmer day, cold engine, the car will idle around 13.5:1 when full cold. The worst i have ever seen was on a day this winter then we had temperatures around 5 F. First off, the UEGO is frozen and takes a few minutes to even work. Next, the car will idle in the low 11's and go off the scale rich as soon as you get on the gas. Even with the car fully hot, the car runs richer than it should with cold air temps. So basically both the coolant and air temp correction factors are off.

Have you diddled with the temperature correction values to straighten out the rich running conditions when cold?

[Jesse IL]

Originally posted by Torqued
Have you diddled with the temperature correction values to straighten out the rich running conditions when cold?
No, Its been too damn cold for me to want to screw with the car, so I just put the stock ECU back in. Got a huge increase in fuel range to boot.

[Torqued]

Originally posted by Jesse IL
Well, the UEGO takes a few seconds to initialize but here's what I see:

Stock ECU: car settles to stoich immediately, regardless of air and coolant temperatures. In general the car does not run any richer cold vs. hot

PFC: car is stoich, but then drifts richer. On a warmer day, cold engine, the car will idle around 13.5:1 when full cold. The worst i have ever seen was on a day this winter then we had temperatures around 5 F. First off, the UEGO is frozen and takes a few minutes to even work. Next, the car will idle in the low 11's and go off the scale rich as soon as you get on the gas. Even with the car fully hot, the car runs richer than it should with cold air temps. So basically both the coolant and air temp correction factors are off.

I just wired in my wideband today. Weather is great for tuning. Anyhow the car idles 11.2 to 12.2 A/F - wow I didn't think it was running that rich! When running WOT, the A/F is running around 12.2:1. I noticed that the car runs off the scale (lower than 11.0:1) under part throttle conditions. My guess is the base map was tuned for WOT, and not much attention was paid to part throttle. I have notice my car has been eating gas with the base map, and the oil has been dirtier than usual, so I need to tune this bad boy before I foul some plugs or deposit a thick layer of soot in the engine!

After seeing what I'm seeing today, I'm glad I invested in the wideband to street tune the car under all conditions.

[Jesse IL]

Sounds to me like you were running the map that comes pre-loaded in the PFC, not the MWR map.

[Oli]

Originally posted by Jesse IL
Sounds to me like you were running the map that comes pre-loaded in the PFC, not the MWR map.

That map ran lean on my car...

[DYI01]

Originally posted by Jesse IL
Sounds to me like you were running the map that comes pre-loaded in the PFC, not the MWR map.

I was thinking this could be the case. Is there a way you can confirm what map is on the PFC. I know a lot of people had problems getting the PFC from MWR with their base map on it. Some people got the basemap loaded, and some people got the A'PEXi crap ass map.

[Torqued]

Originally posted by Jesse IL
Sounds to me like you were running the map that comes pre-loaded in the PFC, not the MWR map.

I was running the MWR map. I have done some tuning today and things are looking much better.

[Jesse IL]

Originally posted by DYI01
I was thinking this could be the case. Is there a way you can confirm what map is on the PFC. I know a lot of people had problems getting the PFC from MWR with their base map on it. Some people got the basemap loaded, and some people got the A'PEXi crap ass map.
The easiest way is to check the redline. You can do that with the Commander or the Datalogit. The default A'PEXi map will have an 8300 rpm redline.

[Jesse IL]

I just put the PFC back in yesterday. Temperatures were in the mid 50's (F) and the car still runs very rich cold. I can say for certain that the coolant temp correction factors do not keep the AFR consistent.

[exotic performance]

can someone help me because my car idles crazy after i let off the gas for about 15-20sec then it will go stable.

[DYI01]

try pulling some IGN timing from the idle area and see if that helps.

[exotic performance]

thanks

[Oli]

Originally posted by DYI01
try pulling some IGN timing from the idle area and see if that helps.

[Torqued]

Originally posted by Jesse IL
The easiest way is to check the redline. You can do that with the Commander or the Datalogit. The default A'PEXi map will have an 8300 rpm redline.

The map had the 8500 rpm setting just like I ordered from MWR. It turns out my main problem was that the PFC came with the O2 feedback control ON. I have since tuned my AF up nicely both WOT and part throttle. It runs between 13.3 and 13.9 under all conditions. The interesting thing is if I turn the O2 feedback on with my AF setting set, the AF will run richer and when I dip my foot into the throttle, the AF goes below 11. Wierd. Unless I figure this out I'll run the PFC open loop.

[2000GTSblack]

It's actually supposed to run a little more rich, for a short while, when you press on the gas, it helps tremendously with driveability, but that's too much unfortunately.

[Oli]

I had a problem with the O2 feedback when I had it turned on. Under light throttle it ran lean 16:1 now I've turned it off my A/F is perfect? I'm going to try replacing the o2 sensor first.

[DYI01]

you can adjust the o2 feedback setting to a setting which will give you an ideal A/F reading. Under Settings 1 the box marked o2 feedback has a number, change that similarly like you would change the INJ or Base map I forget which, but I'm pretty sure its Base. The number is for "lean burn" cruising mode when the TPS sensor hasnt moved in a while. Since you have a wideband I'd fiddle with it and see what happens.

[Jesse IL]

Interesting...I'm gonna have to screw with that setting.