Do all mono blade throttle bodies have high idle issues?

[MalcolmV8]

Malcolm, i just started the car today and im having the same issue as you. My tuner gave me a quick tune so i can start the car otherwise it wouldnt start with the new maf. Did u ever figure out what the issue was with the high idle? Was is the tune being off or a bad throttle body? Did u have issues with vacum? My car always pulls around 21-22 and today my gauge was reading 16-18. Im thinking that also has to do with the tune being off.

Yes a few posts back on the prior page I explain it all. Guess you skipped those ;-)
My tuner couldn't get my car to idle worth a darn and kept telling me my throttle body was bad and who knows maybe I did have a bad one. I exchanged my throttle body with Whipple three times and each one they sent me was better built and sealed more than the last and idle improved with each replacement but never got perfect. Although the difference in how much my very first TB sealed vs the one I have now is quite a bit difference.
The final fix was in the tune itself. I purchased the SCT pro racers package and just started tuning it myself. I got Don Lasota's training manual and videos and with the help of some very helpful folks in this thread figured out how to adjust things in my tune like idle air integrator and idle spark among a few things and have it idling around 850 to 900ish now. Not as low as I'd like but darn near close. Yes I am very picky with it so it is low enough nobody can tell but me.

Your vacuum seems off. I believe mine is still around the 20 ~ 22 at idle. Perhaps you do have a minor vacuum leak?

 

[DSG2NV03]

I just have the factory boost gauge with an overlay, but with a return setup, should you see your fuel pressure when idle, have less psi = to the vacuum? Example: Set fuel pressure regulator to 50psi running (idle) with no vacuum. When you attach the vacuum line, should you be seeing 30psi on the fuel pressure regulator at idle?

 

[MalcolmV8]

I just have the factory boost gauge with an overlay, but with a return setup, should you see your fuel pressure when idle, have less psi = to the vacuum? Example: Set fuel pressure regulator to 50psi running (idle) with no vacuum. When you attach the vacuum line, should you be seeing 30psi on the fuel pressure regulator at idle?

I'm not sure how this question fits in this thread about high idles and mono blade throttle bodies lol. I'm also confused as to what the factory boost gauge with an overlay has to do with your fuel pressure at idle? But yes you are correct at idle when you attach vacuum to your fuel pressure regulator fuel pressure will drop although probably not 20 PSI. I have my base set at 39 PSI and it idles around mid to low 30s if I remember right.

 

[DSG2NV03]

I'm not sure how this question fits in this thread about high idles and mono blade throttle bodies lol. I'm also confused as to what the factory boost gauge with an overlay has to do with your fuel pressure at idle? But yes you are correct at idle when you attach vacuum to your fuel pressure regulator fuel pressure will drop although probably not 20 PSI. I have my base set at 39 PSI and it idles around mid to low 30s if I remember right.

Yes you are right. my apologies. I was simply stating about the factory boost gauge because I cannot read vacuum like in an aftermarket gauge. Was reading a bunch of PRP threads and got caught up with it in yours when someone mentioned a vacuum leak. :bash:

 

[MalcolmV8]

OK Guys,

Discovered something interesting with my MAF transfer function table today and spent about 4 hours tinkering with it in the driveway trying to get it to work and finally gave up. Maybe I'm to picky on the A/F ratio but here's what I have. I'm thinking a pic will help my explanation.

OK see how the lowest "Counts" in the transfer is 108.4. Well when my car is idling (fully warmed) around 79 ~ 80 counts. From experimentation I found that the #/min in the 108.4 row has the most affect on idle. Currently in the picture you will see it's 0.8059. My problem is if I adjust that number so that my car idles at 14.7 or lambada 1.0 when I rev the car lightly (around 1300 ~ 1500 sometimes less) and it's at Counts of 108 it's now lean. Around 15.5 ~ 16 A/F. Of course as soon as it gets to the next set of counts which is 124.8 I can have it back on track for 14.7.

Now if I set the 108.4 #/min column so that I have a 14.7 A/F when the car is actually at 108 Counts on the MAF then it idles rich around 12.5 ~ 13 A/F. I struggled with this for hours and could not find a happy medium. Am I just to picky? Is it no biggy and I should just get idle correct and not mind the minor lean spike as it passes 108 counts?

Also the number below in the 0 counts column I changed a bunch too (currently 0.00488 ). I found I could help lean idle out by lowering the heck out of it as you can see but still couldn't get an idle better than 13.5 unless I leaned out the counts 108.4 row.

Another option I was thinking about and I don't know if this is a big no no or what. What if I changed the 108.4 counts to 80 counts so I would actually be setting A/F at idle and then it would interpolate and make adjustment between it and the next count up of 124.8. Seems like that would make it idle at the correct A/F and rev at the correct A/F too but I wasn't sure if that's the way to do it or not?

2) Another interesting thing I noticed today too was that since I had to lower my idle spark a lot to get my car's idle down to 850 RPMS with the large mono blade TB that doesn't seal well like a factory round unit as soon as I get on the gas (very lightly) it changes from spark source 9 to spark source 2 and as such my spark goes from around 5 ~ 9 degrees to around 32 degrees instantly and causes the RPMs to jump quickly out of proportion to pedal movement. Not sure if there's a fix or if that's just one of those things.

Any insight is much appreciated.

Thanks
Malcolm

 

[03Steve]

Whoa.

Can you post the graph of your transfer function really quick?

 

[MalcolmV8]

I can post it tonight as I don't have my tuning laptop with me at work. Honestly I have not dialed in anything above 260 ish counts. The upper part I have highlighted and done a blanket + 10% as I noticed the first few I messed with below were lean but that's about it.

I also see where there's an abnormality right at 441.9 Counts. See how that number is a dip. I'm not sure how that go in there. Probably something I goofed somehow along the way. I will fix that as I work my way up.

For now I've just been concentrating on that very lower part and trying to get idle and low RPMs perfect and work my way up.

 

[03Steve]

Well, here is one of mine for reference. I wouldn't call the low end of this one "ideal", but the points have been extrapolated for even spacing and into a low working range. I usually populate the first row with zero volts to prevent the car from stalling in case an anomaly brings the MAF into a very low working range:

 

[MalcolmV8]

OK I see where you're going with that. My points are not evenly spaced like that in the beginning. In fact I believe there was a long flat spot at the bottom between widely spaced points but this is from memory. I'll get the graph for you tonight.

So I guess that means it's OK to change the points on the "Counts" column? I was hesitant in case I messed something up.

 

[03Steve]

You can do whatever you want. There are various schools of thought on how to space the points and how to build the air model. Some people like closer spacing down low. Some don't pay attention to it.

My personal preference is zero as the starting point, close to 1023 as the ending. Even increments.

My process is the same every time. I use the data from the sheet, and extrapolate a 30-point curve from a 9-point when necessary. If the data sheet is accurate, there is very little work required on the MAF side. Any gross error if relatively constant may be attributed to the low/high injector slope values. After all, if the air model is measured on a calibrated flow bench and the injectors are just off the shelf...an error may be more likely on the injector side.

For most though, the above paragraph means little or nothing. Most people don't receive a data sheet with their MAF. They work from scratch to build a transfer function, which is what you are doing. Or they rely a some value file from a third party, which isn't really a proper way to tune a car IMO.

In that case, I like to put the car into open loop, and use the air/fuel meter that I trust to calibrate the car. In Missouri most of our gas stations are "up to 10% Ethanol", which means there can be a stoich point anywhere between 14.08-14.64. Some people set to 14.08, some use an arbitrary value in the middle, some do not adjust at all. Again...personal preference. I have the air/fuel meter set to lambda in my case, and my base fuel table is calibrated.

So, assuming you are beginning with a MAF transfer that you a happy with as a starting point, it's time to go to work building the air model. I start with a warm engine. I like to have idle without any adders as it will take you to the lowest part of the operating range of the engine, from an airflow standpoint. Looking at my MAF transfer function from above, here are some of the following points in A/D counts:


361.31
328.55
295.77
263.00
230.23
197.47
164.70


With the engine idling I log:

Load
MAF A/D Counts
Air flow
STFT 1
LTFT 1
Engine Coolant
Open Loop Flag
Spark
Engine RPM
Desired Idle RPM
Air/fuel (expressed in lambda)
Throttle Position Absolute
Throttle Position Relative


To get started, I first verify STFT1, LTFT 1, and Open Loop Flag are all set to 1.00. The STFT 1 is reflecting the base fuel table commanded value from the cell in the car's idle range. LTFT 1 is ensuring that adaptive learning is off, and no long term correction is taking place. Open loop flag is verifying that that car is in open loop, and no short term correction is taking place from factory oxygen sensor feedback.

Coolant temp is good to keep on eye on for a number of reasons. One of which is 178 degrees, which is where the idle air adder stops adding RPM to idle in factory AMZ2 catchcode form.

Engine RPM and desired idle RPM are nice, let's you note if the car is hitting the EEC's idle RPM target.

Throttle position absolute and relative are for a number of things as well.

Looking at my logs, my engine at full temp idles around 165 MAF A/D counts. My commanded base fuel is 1.00, expressed in STFT1. My lambda reads 1.00. If lambda read 1.05, I would need to divide the lb/min airflow cell by 1.05 at the 164.70 A/D count in the MAF transfer function.

My next step is to press the accelerator and hold the engine as close to 197.47 A/D count as possible. Hold it there to get a good steady reading from both the MAF and the wideband. Again, apply the correction to the MAF transfer function as needed. This process repeats up the MAF curve within reason.

Once you are finished dialing in the transfer function, there is an extra step you can take in order to optimize the curve. A fitting. The fitting is a smoothing feature that takes care of minor errors and produces a nice smooth MAF transfer function. There are various orders (3rd-6th) that can be applied to the curve. It is no accident that the curve that I posted above looks like that. It is a combination of a 9 to 30 point extrapolation with fitting/smoothing applied to it.

After you finish with the MAF transfer function, the load with failed MAF table is next. The table is important for anticipatory purposes on quick throttle changes. Explanation for tuning that includes throttle position relative and RPM, holding the car in an RPM column and populating the cells with measured engine load.

Now...there is a problem doing it this way after your tuning session nears completion. The wideband is used as a trusted source over the factory O2 sensors. However, if you choose to put the car back into closed loop, any error between the wideband and the narrowband factory O2 sensors will be present and seen in the short term fuel trims. Correction will take place, with closed loop taking over your work in the short term and applying the corrections permanently into the long term keep alive memory. You have two choices at this point. Identify the error between the factory narrowband and the wideband and calibrate the EEC, or keep the car in open loop.

 

[MalcolmV8]

03Steve, first off thank you for taking the time to write me that info. It's very helpful and very much along the lines of where I was going but you've filled in some gaps I had. I've read you post at least 5 times now.

I think first thing I need to do is change the points along the MAF curve and have 0 and then 80 Counts as my next point which is where my car is idling at.

I too start with my car fully warmed before tinkering with the tune.

I datalog pretty much the same items you do and a few more. I have my notes at home and will post up later.

One thing I noticed is you have "Throttle Position Relative". What's the difference between it and "Throttle Position Absolute"? Absolute is the one I datalog. I noticed you mentioned it down below for MAF failed table. Interestingly in my tuning manual I believe it says you can copy/paste your MAF curve into the MAF failed table once it's tuned. I'll have to go back and re-read that section when I get that far into the tuning.

Reading through your description I do very much the same. Adaptive learning (LTFT) turned off and Open loop mode.

Interesting on the coolant temp. I had not heard about the 178 degree mark where idle air quits getting added. When you say by idle air adder, do you mean the idle air control motor? or IAC valve? I don't have AMZ2 though, I have YDH1.

I was not familiar with "A fitting". Is that a feature of the PRP tuning software to smooth out the curve? Sounds like something I need to look into.

Also very interesting on the MAF failed table. I thought that was purely for when MAF fails so you can still drive the car. Makes sense though for anticipation of air flow on sudden quick throttle changes.

I also know what you mean by offset of the wideband sensor and the factory O2 sensors. When I tuned my turbo'd civic I actually removed the factory O2 sensor and wired the wideband into it and it uses the same sensor so I don't have that issue. It's a completely different setup than the Ford ECU and hand held flash though.

 

[MalcolmV8]

Here are the items I datalog

Here's the MAF transfer chart. Don't laugh lol. Not sure what the dip and really big dip further up are from. Like I said I've only worked on the very lower part but even there it's spaced out very uneven. Nothing like yours. I'll work on that. Now that I know it's ok to change up the counts column I'll make a lot of changes.

 

[jrgoffin]

If your idle is jacked up, can't you use the Motorcraft idle adjustment kit (F2PZ-9F939-A)? I knew it originally was an '87-'93 part that was popular back in my Fox days, but I think it fits under (Or between) most IAC solenoids, including the SN-95's. I could be wrong though...

Here's a diagram:

Pic of the kit from Steeda's site:

Redirect Notice

 

[MalcolmV8]

If your idle is jacked up, can't you use the Motorcraft idle adjustment kit (F2PZ-9F939-A)?

Those allow more air to bleed by which is the exact problem I have. I need to cut back on air not increase it.

 

[jrgoffin]

Those allow more air to bleed by which is the exact problem I have. I need to cut back on air not increase it.

Gotcha'. I didn't have the patience to read the entire thread - that's what I get...

 

[MalcolmV8]

$263.95 with shipping actually. I know I have it. Very up to date stuff. I also have LaSotas disc and book. And both of Banish's books as well. The more you learn, the better.

The more I've gotten into this I've found Greg Banish on my own. I had remembered your post referencing someone's stuff you had said was very good so I came back to check this thread tonight and sure enough it's the same guy. This DVD

Summit Racing SME-DVD-3 - Summit Racing® Ford Advanced EFI Tuning DVDs - Overview - SummitRacing.com

I watched the preview here and it has me sold on it

Calibrated Success Advanced Ford Tuning DVD - Long Demo - YouTube

I also had found his two books here

Engine Management: Advanced Tuning

and

Designing and Tuning High-Performance Fuel Injection Systems

I noticed the books were from 2007 & 2009 and just wanted to see how relevant and good they were too? They're pretty cheap at $25 each for a paper back.

The more I get into the tune on my car the more I find I'm craving more info and this looks like a good way to get it. I wanted to get your feed back on it first because the DVD is pretty pricy at $250 + shipping.

Thanks
Malcolm

 

[MalcolmV8]

BTW - found both of his books on amazon.com for $32 shipped.

 

[04sleeper]

The books give you basic principles and are still good reads.

Glad to see you taking the dive into learning it. :thumbsup:

 

[Nerevarine]

OK guys. Here's my tests tonight.

Car fully warmed first.

Battery cable pulled for 15 min.
Fire up car and it idles at 1500 ~ 1600 rpms.
Unplug IAC and it drops to around 1100 ~ 1200 rpms (or just leave car idling for a long time and ECC learns to close IAC and idle comes down to a best of 1100 ~ 1200 rpms due to air passing in TB.

Battery cable pulled for 15 min.
Seal throttle body blade this time like this with some putty

Fire up car and it idles perfect at 800 ~ 850 rpms.
Pull IAC and the motor dies immediately (very good, tells me IAC was controlling idle).

I don't see how that can be ANYTHING but the throttle body. I guess I will call Whipple in the morning for my 4th throttle body.

Assuming worse case and they can't fix this is there an alternative brand that does work that's the same size that will fit on the 2.9 crusher?

Thanks
Malcolm

Did you ever get this fixed ? I am running into the same issues with my 3.4 Whipple.

 

[Soap]

Did you ever get this fixed ? I am running into the same issues with my 3.4 Whipple.

I'm sure he did by now.....this thread is 5 years old.

--Joe