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Discussion Starter #21
It seems I was using the "General" logging profile, which excludes quite a few fields. I have switched it back
to the "Default" profile which includes everything.

I will post a short log file tonight when I get home after work. It will be from a cold start so you can see everything.

Logging from a cold start you'll see my WUE and how I have to keep the car running during warmup. I tried increasing the added fuel, but that seemed to make it worse.

Side question: How is the Auto-Tune WUE feature? Does it work pretty well? I also would think my WUE is going to change based on the season and outside temperature, no?

I have had it in my plan to get a different TB since this BBK 70MM has always been a pain. I'll put it on my winter "To Buy List".
 

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Discussion Starter #22
OK, I have three logs for you and my tune. All of this was in the driveway.

Keeping this thing running during warmup was more difficult than it was before with my old settings. The
lean spot and throttle issue is overall worse, but while driving, when the accel enrich kicks in, it feels much smoother.
Not sure which one was more in the right direction.

Log #1 is the current tune as is.

#2 - TPSdot% threshold is set to 800%, effectively disabling Accel Enrich.

#3 - Decel amount set to 0, even though I'm pretty sure that wouldn't change anything.

https://drive.google.com/open?id=0BwuZNEwz31xLZGV2TlQ4VmtyZ0k

Can anyone explain why the RPM is logged x100? It makes it a bit difficult to see what's going on while looking at the
Fuel and Ignition table.

Oh, and it looks like I'm going to pickup a 70mm Accufab TB and spacer Saturday morning.
 

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Much better.

Alright I haven't looked through everything yet but I already see something really suspicious. I see this while you're trying to keep the car running when it's cold but even after it's basically up to temperature and running more or less steady.

On your 1st log file at record 9143 which is 2857 seconds in; your AFR basically shows you're getting no fuel. However your injector pulsewidth has begun to increase from a nominal value of 2ms up to 2.6 which is a little over 25% more commanded fuel. Your AFR is then flatlined at 19.7:1 as your motor is dieing even though MS is commanding more and more fuel up to a peak of 6.94ms which is 400% more commanded fuel until record 9168 where it recovers; that is at 2859 seconds.

So it looks to me that the engine is dieing because it's not getting fuel. MS detects this and starts commanding more and more fuel to recover but no fuel is actually being injected and then bam, the fuel suddenly comes back in. It happens again shortly there after but that time the engine actually dies.

This makes me suspicious of your injectors. MS is commanding the fuel but you're not always getting it in the cylinders. When your rpm and tps is steady there should be a direct and obvious correlation between injector pulsewidth and AFR, but yours is very inconsistent. Can you put a noid light on your injectors and see if they're firing consistently? It's possible that there's a wiring issue, or it's possible that an injector driver is bad. Do you have a fuel pressure gauge? Another possibility is a sudden lack of fuel pressure.
 

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Discussion Starter #24
I do have a fuel pressure gauge and although I haven't checked it recently, it has always kept fuel pressure consistently before and after the MS install. Either way, I'll be sure to
give it a look tomorrow or Saturday.

Second, I don't have nor did I know what a noid light was, but I'll ask some friends and or buy a set and test out the injectors.

I took a look at the logs and I see what you're talking about. The obvious correlation between pulsewidth and AFR is if pulse-width goes up, AFR should read rich. However, in my case, pulse-width goes up and it is goes very lean.

Thank you for taking a look.
 

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If you're feeling froggy you can run a 12v LED from radio shack in parallel with an injector and that way you can leave the injector plugged in. We want to know if it keeps flashing while your AFR crashes and the engine is dying.

Especially once the coolant gets up to 160 or more and the engine is mostly running okay with the occasional lean-to-death.

If you do go that route, and you probably already know this but just in case it saves you a minute; the injector hot is constant so it's the ground wire that you have to monitor with the LED.
 

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Discussion Starter #26
I'll just get the proper tools for it.

Would the bad inj driver be fixable? Replacing components on the MS PCB?
 

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I'll just get the proper tools for it.

Would the bad inj driver be fixable? Replacing components on the MS PCB?
It's not likely that there's a bad component, but if it is a bad component it depends on which one it is. Q1/Q5 can definitely be replaced. A connection problem is more likely.
 

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You're welcome. I wrote that one myself after having to walk several customers through troubleshooting their injector drivers and finding myself wishing I could just point them to step by step directions. :)
 

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Discussion Starter #31
Thanks for the responses and info guys.

I was away on business this past week and probably won't get a chance to test all this for a while. After the new year I head oversees for 3 weeks for more training for my job.

So testing the injectors/MS2 will probably take the back burner for now, but at least I've made pretty good progress towards determining the problem.

Thanks again, the help is appreciated.
 

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Recalibrate your tps. I had a similar issue where while driving during light throttle application i would get a momentary lean spike and bucking. Thought my ve table was messed up until i looked at my tps reading. Even though i calibrated the tps for some reason it would go -neg numbers between 10 and 20% tps. took the tps off, cleaned it, checked connection, recalibrated a few more times and now its fine. A nice smooth number from 0 to 100%.

A wildly moving tps would drive MS insane.
 

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Recalibrate your tps. I had a similar issue where while driving during light throttle application i would get a momentary lean spike and bucking. Thought my ve table was messed up until i looked at my tps reading. Even though i calibrated the tps for some reason it would go -neg numbers between 10 and 20% tps. took the tps off, cleaned it, checked connection, recalibrated a few more times and now its fine. A nice smooth number from 0 to 100%.

A wildly moving tps would drive MS insane.
I was thinking this as well. I feel that all the sensors should be perfectly calibrated before trying to modify the tune much
 

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Discussion Starter #34
Hey guys,

Thanks for your input and coincidentally comes at the perfect time.

I had a BBK 70MM TB on my car that was in rough shape. It "worked' but had some blade movement/wiggle when fully
closed. In addition to that, when I calibrated my TPS with the car off, it'd be at 0% but at idle the TPS would read between
-2 and -5%. The computer engineer in me didn't like it but I was told by my tuner and other people that it shouldn't effect the car as much as it was.

I wanted to fix this before doing anything else so I bought an accufab 70MM, which is overall just higher quality and installed it. Oddly enough, that didn't seem to completely fix the negative TPS issue at idle.

I said screw it and calibrated the TPS at idle (since from everything I've read it should be calibrated with the car off), so it now reads ~0% (give or take .1 or .2% positive or negative). I did try this is the BBK TB but it didn't help.

In reality, when we think about the issue, if I give the car 10% throttle, but the computer is "reading" that 10% minus error from idle (2-5%), it is getting the airflow from 10% but only adding the fuel of 5-8%, which would cause it to go lean. Especially at this small amount of throttle. The amount of air flow at idle versus 10% is exponentially greater, especially at the initial inrush. So it does make sense, at least to me it does. Maybe I thinking about it incorrectly.

It seems, with this accufab, it did help. Now when I hit the throttle is goes super rich, which makes sense since my tuner has the tune quite rich in hopes of band-aiding that lean issue. I pulled some added ms out of the AE, which helped some, but I'm having to tuner come out sometime soon to do a little drive and tune.

I need to get the car plated and back on the road first.

I'll provide another update when available.

Thanks everyone for assisting.
 

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https://www.diyautotune.com/support/tech/hardware/diypnp/documentation/application-docs/1988-1993-ford-mustang-5-0l/

Sensor Calibration

This vehicle has a variable TPS. You should calibrate it properly from TunerStudio in the ‘Tools’ menu. Choose ‘Calibrate TPS’.

1. Make sure the engine is off, and the key is on.

2. With your foot off of the throttle, click the ‘Closed Throttle ADC Count – GET CURRENT’ Button.

3. Put the throttle to the floor. With your foot fully depressing the throttle, click the ‘Full Throttle ADC Count – GET CURRENT’ Button.

4. Click Close.
 

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Discussion Starter #36
Yes, I know how to properly calibrate the TPS as I stated in my last post. I've done it over and over and over again with the same result.

As soon as I start the motor, the TPS drops negative; somewhere between -2% and -5%.

When I calibrated the TPS when the motor was running, it seemed to fix the issue.

Whether the process is right or wrong, it seems to have fixed my issue.

Unless anyone can think of a reason as to why my TPS goes negative when I start the car, I plan to keep calibrating it this way. It is a brand new TPS, and although I plan to buy another to compare to, I don't foresee that being the issue.
 

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I dont see it being an issue calibrating closed position while engine is on. If it goes rich while revving the car you now have to play with time based enrichment. Your tuner probably fattened that up trying to solve that lean issue
 

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Discussion Starter #39
I dont see it being an issue calibrating closed position while engine is on. If it goes rich while revving the car you now have to play with time based enrichment. Your tuner probably fattened that up trying to solve that lean issue
Yep, exactly right. Tuner told me that right off the bat. So now that I've seem to have found the cause, I'll play with the tune myself a bit and eventually have the tuner come out and tweak it a bit.

Once I found that the TPS calibration was the issue and saw how lean it was going I immediately pulled fuel from the AE.

I agree, there shouldn't be an issue calibrating the TPS this way; as long as idle is 0% and WOT is 100% there shouldn't be a problem. (?)

As far as my exhaust setup goes; yes, I'm using a Spartan WB O2 sensor and controller mounted in the stock H-pipe O2 location. Don't recall if it is on the driver or passenger side though. I'd have to take a look again. For the record, I'm using unknown brand shorties, catless H-pipe, and the Borla catback.
 
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