Troubleshooting my Wideband and Ground Reference

[Sendero]

I have my Zeitronix Wideband connected to the TwEECer via a DataQ serial connection. The wideband has been off of the car for a couple of months, but before I removed it I was having "wierdness" at idle.

The Wideband O2 is installed in the Drivers side rear O2 hole of my Dr. Gas X-pipe. During warmup the wideband reads about 13.8:1 but as soon as the car gets to 195* and the fuel trims kick in, the WB bounces between 16:1 to 18:1. The only way is reads anything less as idle is if I goose it and bring the RPM's up.

Is it possible that the WB is to far down the pipe to get accurate readings?

I was reading something about the "ground reference voltage" on the other forums, but it seemed that this was for the EGR installation. Do I need to ground my DataQ to the same place as the EEC?

[86GT]

I am seeing something like this on mine (PLX). It starts up and the WB reads 12 and then slowly goes lean at about 45 sec. Then when 90 sec hits it goes down to normal 14.64.

I have tried all kinds of things. I don't know if this is a way for ford to heat up the cats or not. It starts up with no problem, it just has this weird lean spot in the between 45-90 sec. If it is a warm start the lean spot is around 30-40 sec marker.

Maybe we need to try the other bank. We might have an exhaust leak that I can not hear. I wish I had one of those smoke machines that can help find leaks.

[Dale McPeters]

Could it be the transition from OL to CL? The one based on time or ECT?
Maybe it is not making a smooth transition?
Just a thought......

[Sendero]

Well, mine "makes the change" and stays that way. Zeitronix says to place the WB O2 about 24" away from the rear exhaust port and with it in the rear hole its about 30". I'm just trying to determine if the extra 6" is to much.

[Dale McPeters]

Well it should not make a difference as I have the FJO-WB sensor that I am using down in the x-pipe, of course it uses a different sensor and electronics.
Oh well...........

[gt90stang]

The Thermactor Air Diverter (TAD) is active for the first 45-180 seconds on startup. This will cause a very lean reading until it goes to normal operation. To actually check AFR during cold warm up you need to disable the TAD temporarily.

Don

[Dale McPeters]

Where have you been Don?
By the way I do not use TAD........ :jester:

[gt90stang]

Dale,

Been tuning and learning way more about the PCM than I intended! Argggh! The good news is I've figured out the demons in my setup and am working on very fine tweeking.

Don

[86GT]

The Thermactor Air Diverter (TAD) is active for the first 45-180 seconds on startup. This will cause a very lean reading until it goes to normal operation. To actually check AFR during cold warm up you need to disable the TAD temporarily.

Don

Thanks Don, this explains what I am seeing. The only thing is mine happens from the 45 second mark to the end of startup mode or 180 sec. It does not see this lean spike the first 45 sec.

I will have to try disabling the TAD tomarrow.

[Dale McPeters]

Dale,

Been tuning and learning way more about the PCM than I intended! Argggh! The good news is I've figured out the demons in my setup and am working on very fine tweeking.

Don

Don,

Good deal glad to see you figured out the demons.... :chug:
If you do not mind post pictures of your setup in the Studio section as I had seen something on yours that I wanted to look at.....
I am still tinkering with the little blue car & the '93gt. Have also been working on the '03 Mach 1 stuff more as I have time.

Dale

[gt90stang]

Dale,

What specifically are you interested in...may be on my website at http://geocities.com/dbennettya/Mustang_PCM

Don

[Dale McPeters]

Don,

It was on your site. I just wanted to see how the canton overflow tank worked out and what kind of clearance is available. I will be running very tight on clearance in that area, may have to relocate to another area.

[Sendero]

Ok, new problems:

Attention: 1996 Cobra - LLX3/CDAN4

I got the WB working and decided to throw my C&L 80MM Meter and Tru-Flow inlet pipe back on the car and start from scratch. So I've got everything installed and a fresh set of spark plugs thrown in for good measure.

First, the car will not idle with the C&L 80MM "Blue Tube" transfer loaded from EA. I load up the stock LLX3 transfer and it fires right up, but I am way lean.

Here I go...

I disable Adaptive Strategy and datalog about 10 minutes of idle. I send the datalog through EA and calculate a new idle curve (ie voltages between .53 and .74) to target 14.67. The car now idles around 650rpm and 14.6-15 AFR. Sometimes I have to hit the throttle just to make sure its still running! Set out to do some datalogging to dial in my MAF curve. After about four 30 minute sessions I have a nice smooth curve that produces (fairly) identical LAMBSE and WB readings.

With Adaptive still disabled I do another 30 minute session to calculate injector timing. Surprise, Ford was conservative with injector timing on the DOHC's. (Used TDC and Trailing) I picked up a good bit of mid-range torque (Bubba's Seat-o-Dyno) and it does sound different. I'll have to report later on the fuel mileage. Did another logging session just to make sure the curve did not change.

With all that worked out, I turned Adaptive Strategy back on and set Thermactor Air Injection Hardware Present to 0 hoping to disable it.

My issues...


During warmup, the car chugs and idles like it has a lopey cam. It didn't do this with Adaptive disabled, but with the KAMRFx's cleared and ECT low there shouldn't of been an issue?
Even with Thermactor Air Injection Hardware Present disabled, I can still hear the relay click and the WB goes to 20.00. Any ideas?
Crusing at a steady RPM (not gear dependant) will get you some strange readings. For example on the Interstate with cruise set at 75mph my LAMBSE and WB were reading 14.xx, but my KAMRFx's were going nuts and showing .91x to .89x. If my LAMBSE and WB are matching up why is the EEC trying to correct fuel?
Sometimes the EEC will command 16.5x-18.3x during part throttle/low load (40's or below) steady state cruising. My fuel_stabilized_OL is set to 14.64, what else is causing it to command such lean mixtures? (Keep in mind that my WB is still matching the LAMBSE)


So what am I doing wrong?

[Sendero]

:bump:

[boss96]

During warmup, the car chugs and idles like it has a lopey cam. It didn't do this with Adaptive disabled, but with the KAMRFx's cleared and ECT low there shouldn't of been an issue?

Since the car did not learn any fuel trims you do not have any trims applied to cold start. It is doubtful that you have the maf dialed in perfectly so you may be running lean when cold.

Even with Thermactor Air Injection Hardware Present disabled, I can still hear the relay click and the WB goes to 20.00. Any ideas?

Sorry, no idea :(

Crusing at a steady RPM (not gear dependant) will get you some strange readings. For example on the Interstate with cruise set at 75mph my LAMBSE and WB were reading 14.xx, but my KAMRFx's were going nuts and showing .91x to .89x. If my LAMBSE and WB are matching up why is the EEC trying to correct fuel?

First thing, the wideband reading is not absolutely accurate, the eec normally will constantly be adjusting the a/f using the stock sensors. If the car is in CL then your Lambse reading should be constantly changing too.


Sometimes the EEC will command 16.5x-18.3x during part throttle/low load (40's or below) steady state cruising. My fuel_stabilized_OL is set to 14.64, what else is causing it to command such lean mixtures? (Keep in mind that my WB is still matching the LAMBSE)

The eec is commanding a lean mixture to compensate for the maf curve being wrong at that point, your wideband is showing the normal 14.7 because the eec is successful at triming your fuel to get to 14.7. Again, this assumes you are in CL, not OL. Your "fuel stab OL" table is not active at this point so it does not matter what it says unless you are running in OL.
Bob

[Sendero]

Since the car did not learn any fuel trims you do not have any trims applied to cold start. It is doubtful that you have the maf dialed in perfectly so you may be running lean when cold.


Just for kicks, I disabled Adaptive again this morning (while the ECT was at 72*) and the car idled perfect. Re-enabled Adaptive (while the ECT was at 96*) and it chugged.


First thing, the wideband reading is not absolutely accurate, the eec normally will constantly be adjusting the a/f using the stock sensors. If the car is in CL then your Lambse reading should be constantly changing too.


Which they are, within a range. Disable Adaptive and clear the EEC and you get matching readings. Enable Adaptive and you get massive corrections.


The eec is commanding a lean mixture to compensate for the maf curve being wrong at that point, your wideband is showing the normal 14.7 because the eec is successful at triming your fuel to get to 14.7. Again, this assumes you are in CL, not OL. Your "fuel stab OL" table is not active at this point so it does not matter what it says unless you are running in OL.
Bob

:doh: For some reason I though that the F_S_OL table influenzed the CL operation too. Anywho, I am lost as to why with Adaptive disabled that LAMBSE and WB reading match but when I enable adaptive they are way wrong.

[boss96]

How are you disabling "adaptive"?
Bob

[Sendero]

How are you disabling "adaptive"?
Bob

Scalar Adaptive_Control_Switch set to ZERO

[Dale McPeters]

Scalar Adaptive_Control_Switch set to ZERO

Are you using the TwEECer for this?

[QWKSNKE]

yes he is

[Dale McPeters]

yes he is

Then..........
Just an idea but it may be possible that the switch is not pointed at the proper data location in the binary file if it really is available in your calibration, had this happen when I was testing some '03 Mach 1 stuff. I would drop Mike Glover an email just to confirm that you have the latest data file for your application. I know that this works on the '03 Mach 1 cars.

Try using the ACT max/min scalar to disable adaptive and see what happens.
On the TAD/TAB thing if I remember correctly you have to set the proper bits to get the desired results. Chris made a post on this a while back if it is still on the EEC-Tuning forum.

[boss96]

Dale, the tag is correct, I have the same strategy. When you turn off adaptive it still runs in CL but does not learn fuel trims. Of course if you have not cleared KAM then you will still have the old trims applied but they are not updated.
Another advantage of no adaptive is the ISC stuff does not adapt either. On my car the adaptive stuff would get fooled by the longtubes, etc, and the car would usually not run that well as far as stalling, etc.
I don't know SENDERO's combo but if he has longtubes, blower and cams I would just run it full time OL and dial in the maf for 14.7 a/f during part throttle and adjust the ISC for best operation.
Bob

[Dale McPeters]

Bob, Was not sure on the tag being correct as I know Mike had been updating
quite a few things according to Clint and some of the others. I am not sure what his combination is either....

Do you have the Cat Temp Switch in your startegy? I forgot what year that started in...
I know on the '01 Cobra's & '03 Mach 1's etc. this has to be changed or it will throw the AFR off...

Also have you heard anything about the '05 release? :jester:

[boss96]

Do you have the Cat Temp Switch in your startegy? I forgot what year that started in...
I know on the '01 Cobra's & '03 Mach 1's etc. this has to be changed or it will throw the AFR off...

Don't think I have that tag, I know about it on the newer cars though, all it does is add fuel when you let off the gas from wot to cool the cats from what I understand.

Also have you heard anything about the '05 release?

Yeah, should be any minute now :metal: :jester: :jester: :jester: :jester:
Bob

[Dale McPeters]

Don't think I have that tag, I know about it on the newer cars though, all it does is add fuel when you let off the gas from wot to cool the cats from what I understand.

I thought that was what they were using it for just was not sure.


Yeah, should be any minute now :metal: :jester: :jester: :jester: :jester:
Bob

:lol:

[Sendero]

I don't know SENDERO's combo but if he has longtubes, blower and cams I would just run it full time OL and dial in the maf for 14.7 a/f during part throttle and adjust the ISC for best operation.
Bob


C&L Meter and a Dr. Gas X-pipe only.

Adaptive disabled with or without the EEC cleared, it idles smooth. Adaptive enabled with or without the EEC cleared and it chugs.

Also for kicks, I put the Stock LLX3 curve back in and cleared the EEC. With Adaptive OFF the LAMBSE doesn't match my WB at all, but with Adaptive ON the trims stay close to 1. I know the MAF curve for the LLX3 can't be correct for a C&L 80mm, right?

[boss96]

No one mentioned this yet but how about changing your 02 sensors? Maybe they are going bad.
Also, did the problem start when you changed the injector timing values?
Bob

[Sendero]

No one mentioned this yet but how about changing your 02 sensors? Maybe they are going bad.


Replaced 6 months ago. Purchase from the Ford Dealer. (Bad experience with Advanced Auto O2's with the 89GT)


Also, did the problem start when you changed the injector timing values?
Bob

Nope. All my values at low load idle are pretty much stock, the big change was above 4000rpm.

[boss96]

Wish I was there to look at it. Want to send me the .ccf and maybe I'll see something?
Bob

[Sendero]

Wish I was there to look at it. Want to send me the .ccf and maybe I'll see something?
Bob

Sure. I'll have to do it when I get home. I'll upload it to my website and you can download it directly instead of messing with email.

[boss96]

Took a look last night at your site and did not find it. Where should I look?
Bob