Random mis not showing on tuner studio

[Tonyorlo]

I hate to ask about this on here, but I am stumped. I have a ford 2.3 with ms2 v3.57 and a tfi ignition. My problem is, when the car is cold, I have a random miss, or something is cutting out. My rpms stay steady on tuner studio, but when this happens my factory tach will drop 2-300 rpm. Does not matter if it's at idle or 3000 rpm, it will do this, but at random. Once the car is warmed up it happens less and less.

Coil, module, cap and rotor are new, plugs and wires are not too old. I've checked all my connections 10 times and everything appears good and clean. I am stuck, and I hate to ask such a basic question on here, but maybe someone can tell me something I don't know? Any thoughts?

[elutionsdesign]

[Matt Cramer]

Also note that if you hit the space bar while logging, that will leave a mark in the data log so that someone reviewing the log can look right at that spot and see if anything is amiss.

[Tonyorlo]

I did not know that Matt, that is very helpful. I logged the problem earlier. The log is much longer than it needs to be, but the problem occurs in the first minute. This was with the car in neutral, and parked. It does the same thing while driving.

[yzn]

You need to fix the injector dead time setting first. Are you running low impedance injector?
There seems to be too much lean area in the ve table try to adjust that to run a bit richer

[Tonyorlo]

I have high impedance 14lb injectors. I did have low impedance 38lb injectors in there when I first converted to efi, but this car is n/a and I was hoping that switching to smaller injectors would help the idle out.

When the problem occurs the a/f ratio does bounce around a lot. What would you recommend I try for the dead time?

[yzn]

Just turn the PWM current limiting to off. What firmware are you running, you should run the latest one.

[Tonyorlo]

Yeah its the latest version. I will try that, Thanks!

[Tonyorlo]

Well that seemed to help a little, I didn't get to put any highway miles on it though. I did get a datalog, and tried to hit the spacebar when it was happening, but its not as nearly as bad. After looking at the log, its seems like I am getting lean spikes when it happens. I guess I am confused because it happens on flat ground and the throttle position is staying steady.

[BigLou240sx]

Seems like you are adding a substantial amount of fuel (32ms) on TPS AE events. Perhaps you're drowning your engine on throttle input? I would reduce your AE... I don't see it actually needing that much fuel on throttle input/tip in.

Also, maybe you need to add fuel in your VE table... if you plot VE1 on the same graph as MAP, RPM, and AFR, you will see that as RPM increases, MAP stays the same or increases, VE goes down and follows AFR up.

[Tonyorlo]

Off of idle, if I give it too much throttle it hesitates. It could be flooding like you said? Just so I understand what your saying, I graphed map, afr, ve, and rpms, and when the map, and ve increases so does the afr. I want the afr to decrease instead increasing right?

So ill back the AE down, and increase the areas in the ve table where the afr is dipping. For now, would it be smart to turn the AE off until i get this straightened out?

Also, looking at the graph and everything is steady, the afr spikes high randomly. What would cause that?

Sorry for the dumb questions, I am trying to learn lol.

[Tonyorlo]

heres a screen shot of an example of what I was talking about with the afr spikes when no change in tps. I am lost?

[yzn]

Try to change your target AFR to 14.0 anything below 70 KPa, and fix the VE table to reach that target. And after the engine warmup.
Why do you have four 6000rpm column in the VE table? if you think that 16x16 is big change it to 12x12

[Tonyorlo]

So everything below 70kpa across the map I should set to 14? Honestly, I don't know why I have 4 rows of 6000 rpm, I've never really messed with the map in that area. I'll shrink it down,and give that a try thanks!

[BigLou240sx]

heres a screen shot of an example of what I was talking about with the afr spikes when no change in tps. I am lost?

Misfires generally show themselves as lean spikes on AFR (unburned fuel), which can be caused by several factors (regardless if it's a fuel or ignition issue). If you were feeling the car miss, it looks like the AFR reading is at least a symptom of those misfires.

[BigLou240sx]

Off of idle, if I give it too much throttle it hesitates. It could be flooding like you said? Just so I understand what your saying, I graphed map, afr, ve, and rpms, and when the map, and ve increases so does the afr. I want the afr to decrease instead increasing right?

So ill back the AE down, and increase the areas in the ve table where the afr is dipping. For now, would it be smart to turn the AE off until i get this straightened out?

The part of the log that I was commenting on was at time 22977sec, where MAP stayed at approximately 60kpa from 1400-2400rpms. Across the rpm sweep, VE1 goes from 60 to 50 and AFR increases. As RPM is increasing, VE should likely at least stay the same or increase.

Turning off AE may be a good idea for now, just expect a hesitation on tip in (for the opposite reason - lack of fuel vs over-fueling). Otherwise, I would just cut your added ms at every TPSdot by quite a bit (half at least)

Your VE table has a lot of peaks/valleys and is not very smooth. This may not solve your miss right away, but generally the VE table should be smooth and follow some general trends. For the extra 6000RPM bins, if you don't want to use them for now, I would at least make them all unique on the RPM scale (6002, 6003 etc). There are a few VE bins that are not matching the same RPM/Load, and I would think the firmware wouldn't like to deal with that when you get up that high.

[Tonyorlo]

I am still fighting this problem, Ive checked the ignition system multiple times, and have been replacing parts with no luck. I logged my drive this morning, and this was the most extreme case of it happening. Its showing up on tunerstudio, I hit the space bar when it happened.

[BigLou240sx]

I am still fighting this problem, Ive checked the ignition system multiple times, and have been replacing parts with no luck. I logged my drive this morning, and this was the most extreme case of it happening. Its showing up on tunerstudio, I hit the space bar when it happened.

Did you make any changes to your msq? Can you post the latest?

You are without a doubt misfiring... but I do not see spikes in pulsewidth that are lining up with the misfires, so my inclination is to look at the ignition system. What parts have actually been replaced?
The 3.57 MS2 manual shows two types of TFI installations, one using Fixed Duty and one using standard dwell for Duty Type. Are you sure you are using the right one?

I am surprised that 26ms of injector pulsewidth at 2500rpm is resulting in AFRs in the 13's, but I'm not used to looking at small injectors with long pw. However, following that amount of injection pulsewidth up, you run out of time available for injection (IDC over 100%) at 4400rpm (and are over the 80% dc safety level at 3600rpm). Does that sound right for what the stock ecu/injectors provided? Is your wideband calibrated? Fuel pump and fuel pressure regulator working?

[Tonyorlo]

I made my fuel table 12x12. I have done some driving with the auto tune to get the table worked out. I have replaced plugs, wires, cap, rotor, ignition module, and coil. The only part I have not replace is the distributor, but these signs dont lead up to a bad pickup really. I have it on fixed duty, I went by the instructions on diyautotune.com. That could very well be the problem. I also played with the advance table.

The car is N/A, I did start with 38lb injectors from a turbo 2.3, but then swapped to 14lb injectors. I really dont like seeing the pulsewith that high, maybe I should put the 38lb injectors back in? Im not 100% about the injectors, Ive gotten some help from people on here with their settings. Yes I did calibrate the wideband, I have checked the fuel psi with a gauge and its fine. Never checked it with the engine under load, but this doesnt at too much like it running out of fuel.

[Tonyorlo]

I am going to try standard dwell type, but what should I start the nominal dwell and spark duration to? The only article I found on it only said to set the maximum dwell duration to 8 ms. After I get that straightened out I might try putting the 38lb injectors back in.