F/IC MAF Volt Clamp? - Page 2 - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


Reply
 
 
 
LinkBack Thread Tools Search this Thread
Old 04-09-2009, 10:47 PM   #21
Junior Member
 
Join Date: Dec 2007
Location: Santa Fe, TX
Posts: 95
Total Cats: 2
Default

Quote by Mikeymx5:
"Ill send it out... "

If you would have followed through with what you said you were going to do...I might help you out with your bucking issues...99-00 versus 01+ vvt
secretsquirrel is online now   Reply With Quote
Old 04-10-2009, 11:27 AM   #22
Junior Member
iTrader: (2)
 
Join Date: Aug 2008
Location: Richmond
Posts: 117
Total Cats: 0
Default

Just noticed that the email had bounced, Ill send it again later today.
Mikeymx5 is offline   Reply With Quote
Old 04-10-2009, 04:02 PM   #23
Junior Member
iTrader: (2)
 
Join Date: Aug 2008
Location: Richmond
Posts: 117
Total Cats: 0
Default

your email keeps bouncing, I sent one with out an attachment to see what happens.

Ill take some screen shots later today, once i figure out how to connect the Wide band, since my harness appears to not have a Aux in wire :(
Mikeymx5 is offline   Reply With Quote
Old 04-13-2009, 12:27 PM   #24
Junior Member
iTrader: (2)
 
Join Date: Aug 2008
Location: Richmond
Posts: 117
Total Cats: 0
Unhappy

Quote:
Originally Posted by atomicfrawg View Post
That about where I had everything set at. But I think I was running the MAF clamp at 4.5. I also had MAF table at 14%.
I had tons of bucking at 2800 RPM and 4500 RPM. I was logging AFR data and INJ duty cycle. At those 2 RPM points AFR and INJ duty went nuts.
I just pulled all of it out and put the FM voodoo back in.
The car just was totaled so I wont have a chance to find out why this was happening.


Chris L
Sucks that you did not solve this, my 2003 is having the same problem, I tried tuning it out but can seem to figure out what the ecu is doing. The AFR just go nuts, and then they are fine after. This is even out of boost even though I masked it by playing with the MAF signal.


Why does the FIC need a voltage clamp? My xede works fine and it doesnt clam the MAF at all.

For now I returned to the xede until I can figure out what is going on.
Mikeymx5 is offline   Reply With Quote
Old 04-13-2009, 03:15 PM   #25
Junior Member
 
Join Date: Dec 2007
Location: Santa Fe, TX
Posts: 95
Total Cats: 2
Default

Quote:
Originally Posted by Mikeymx5 View Post
Why does the FIC need a voltage clamp? My xede works fine and it doesnt clam the MAF at all.
You should read and understand "FIC Tuning Tips" and "Xede Tuning Guide" before comparing the two:

http://forum.aempower.com/forum/inde....0;attach=3700

- it explains the purpose of the MAF voltage clamp with the FIC.

http://www.xede.com.au/files/XEDE%20...20Version).pdf


Comparing these piggybacks is like comparing apples to oranges.


Personally since I was going to be the one tuning my car, I much preferred the more straight forward manner the AEMFIC handles fueling - by intercepting injector signal AFTER the ECU versus the Xede spoofing the MAF signal going INTO the ECU. See page 11 in the Xede tuning guide in regards to how timing is affected by changing the loads that the ECU sees. From FIC tuning tips: "Modern ECU’s can detect even the smallest changes in calibration of these signals." i.e. causing CELs and even having the ECU "fight back" your tuning. My thought was: why try to force or trick the ECU into doing something it's not programmed to do (Xede), when the ECU doesn't even need to know what is going on "behind it's back" (AEMFIC).

Many issues like bucking are ECU "fight backs".

The one thing the FIC itself does not do is advance timing, but you can use the FIC to spoof input signals to the ECU to get the ECU to advance timing....

You really need to know how different these two are and understand "how they work" before you start tuning...

Read everything you can get your hand on, digest, and really understand how this stuff works, and you WILL be successful at tuning & troubleshooting - that's how my dumb *** did it - of course with my education to all things turbo via miataturbo.net!

Good Luck...

Last edited by secretsquirrel; 04-13-2009 at 03:26 PM. Reason: Clarification...and props to the forum.
secretsquirrel is online now   Reply With Quote
Old 04-13-2009, 03:41 PM   #26
Junior Member
iTrader: (2)
 
Join Date: Aug 2008
Location: Richmond
Posts: 117
Total Cats: 0
Default

I understand the difference in the units, it one of the reasons I wanted to change to the FIC.

Bad part is that I dont have a stock car to take original logs from. So Im having to start out tuning with 550cc injectors and a turboed engine.

Whats really getting me is Im having the bucking problems out of the boost area. Im just taking the car line by line on the fuel map and trying to tune it before going to the next level.

Do you thing that if i log the MAF voltage at high rpms and no boost, it would give me a pretty good place to set the Voltage clamp? I speaking of an equivalent clamp voltage of a non boosted car.
Mikeymx5 is offline   Reply With Quote
Old 04-13-2009, 05:10 PM   #27
Junior Member
 
Join Date: Dec 2007
Location: Santa Fe, TX
Posts: 95
Total Cats: 2
Default

The MAF clamp voltage would be the highest voltage the ECU would see when normally aspirated (high rpm/high load). Tough to get that right with the turbo on the car even with wastegate trickery - the turbo will still be a factor, larger injectors are not. One thing though...how are you reading the MAF voltage? Through the ECU with scan tool, FIC live display, or FIC logger? It is the ECU that you want to keep happy...
secretsquirrel is online now   Reply With Quote
Old 04-13-2009, 05:13 PM   #28
Junior Member
 
Join Date: Dec 2007
Location: Santa Fe, TX
Posts: 95
Total Cats: 2
Default

Do you have a logging scan tool that would enable you to see what event/events are taking place when the bucking occurs? Maybe VVT transition?
secretsquirrel is online now   Reply With Quote
Old 04-20-2009, 07:47 AM   #29
Junior Member
 
Join Date: Oct 2005
Location: New Hampshire
Posts: 248
Total Cats: 0
Default

Just so you guys have a larger feedback pool to work with. I didn't even hook my F/IC upto the MAF as most of the other Miata tuning solutions don't either. Other cars need a clamp but the Miata doesn't, unless you are running more boost with the F/IC then you probably should be. The buck you are seeing upon entering boost is related to the o2 clamp. I had the exact same problem with my setup and to took a bit to work out. I don't have the files on this computer but, I'll try and post some images soon.
kingofl337 is offline   Reply With Quote
Old 04-20-2009, 11:15 AM   #30
Junior Member
iTrader: (2)
 
Join Date: Aug 2008
Location: Richmond
Posts: 117
Total Cats: 0
Default

Hmm, thanks... I havent had time to plug this back in and play with it but I guess I could easily remove the MAF connection to eliminate it as being a problem. I think that you are right about not requiring the MAF connection unless you are wanting to emulate it to remove it.
Mikeymx5 is offline   Reply With Quote
Old 05-10-2009, 09:59 PM   #31
Junior Member
 
Join Date: Oct 2005
Location: New Hampshire
Posts: 248
Total Cats: 0
Default

Sorry about the delay I've been traveling ALOT! I created a thread with my cal file in it.

https://www.miataturbo.net/forum/t34968/#post407021
kingofl337 is offline   Reply With Quote
Old 05-10-2009, 11:35 PM   #32
Junior Member
iTrader: (2)
 
Join Date: Aug 2008
Location: Richmond
Posts: 117
Total Cats: 0
Default

great thanks, Im working on mine and Ill post it up as soon as I have something working.
Mikeymx5 is offline   Reply With Quote
Old 05-12-2009, 01:21 PM   #33
Junior Member
iTrader: (2)
 
Join Date: Aug 2008
Location: Richmond
Posts: 117
Total Cats: 0
Default

So I have been playing with the car, if I set the MAF clamp to 3.38 I have problems with lean out under 3K rpm in low gear acceleration
If I set the MAF clamp to 4-4.5 I get the bucking at 3k

I really need a stock 2003 to take some reading from so i can set my base map up.

Is there a way to make to 02 map to not touch the 02 signal until in boost and then send a fake 14.1.

I see that I can set a fake voltage, where 0 is no change and a number is a voltage out.
Or I can set a pulse out, but I dont want to fake the 14.1 out of boost.

For now I think that I will set the fake 14.1 02 in all cells just to eliminate it from the tuning equation.
Mikeymx5 is offline   Reply With Quote
Old 05-12-2009, 06:43 PM   #34
Junior Member
iTrader: (2)
 
Join Date: Aug 2008
Location: Richmond
Posts: 117
Total Cats: 0
Default

Keep in mind that Ill my comments refer to 14.7 psia and below... I havent started tuning in boost because of map problems.
Mikeymx5 is offline   Reply With Quote
Old 05-12-2009, 09:38 PM   #35
Junior Member
 
Join Date: Oct 2005
Location: New Hampshire
Posts: 248
Total Cats: 0
Default

You don't need to clamp the map on a miata, you will not gain anything by doing so.
kingofl337 is offline   Reply With Quote
Old 05-14-2009, 06:44 PM   #36
Junior Member
iTrader: (2)
 
Join Date: Aug 2008
Location: Richmond
Posts: 117
Total Cats: 0
Default

OK for all you 2003 Miatas - you must run firmwares 300.hex and z110.hex. Apparently mine was running z114.hex.

This fixed the stumble at 3K rpms. Im now actually getting somewhere in tuning. they have very poor documentation on what slave version you should be running.
Mikeymx5 is offline   Reply With Quote
Old 05-15-2009, 03:00 PM   #37
Junior Member
 
Join Date: Oct 2005
Location: New Hampshire
Posts: 248
Total Cats: 0
Default

they have very poor documentation on what slave version you should be running

Your 100% right they should specify in the software or the manual what version the slave needs to be. Don't forget to share your maps as you progress.
kingofl337 is offline   Reply With Quote
Old 05-27-2009, 11:07 AM   #38
Junior Member
iTrader: (2)
 
Join Date: Aug 2008
Location: Richmond
Posts: 117
Total Cats: 0
Default

I think that I am going to pull the MAF connection off the FIC. I have tried all values between 13-16% and I run into the same problem every time. At idle I can get a perfect fuel trim, but around 5000 rpm the car is rich.

I noticed that as i pass 3K rpm the car will start to jump to rich - it appears that this is when the car is moving out of closed loop. The AFR will slowly drop until Im at 10.1 at 7K rpms. To fix this i had to make my fuel map remove more fuel as the RPMs more up.. I only talking about in vacuum at the moment.

Looking at my logs my MAF signal has increased over half a volt in the upper range do to the added 13%, I have a feeling that this is not right and the correct way to do this is to start at idle with 13% and reduce down towards 0% as you start to reach 5volts from the MAF.

I agree with another user on the forums that left his MAF disconnected from the FIC.... if it is not doing anything why added to the pool of variables. Later if I decided to simulate the MAF I will rewire it back in, but at least I can then know if it is a MAF table that needs to be fixed vs a fuel and/or MAF table combined.

Being an Xede user I can tell you that the ECU doesn't require a voltage clamp, the xede would some times add 5% to the MAF to get the correct fuel, So I'm sure that there is plenty of MAP on the Factory ECU to handle the MAF under boost.

I will post my cal once I have something worth presenting.
Mikeymx5 is offline   Reply With Quote
Old 06-01-2009, 03:40 PM   #39
Junior Member
iTrader: (2)
 
Join Date: Aug 2008
Location: Richmond
Posts: 117
Total Cats: 0
Default

So pulling the MAF connection made it a little easier to tune, but my car still has the rich spike right at 3K RPM and its perfectly fine after 3500

Dont know whats going on, but with out the MAF connected the spikes are much smaller that I cant feel them while driving.

Did notice some RPM spikes in the logs, dont know what that it all about, but it may be my problem.
Mikeymx5 is offline   Reply With Quote
Old 06-05-2009, 01:15 PM   #40
Junior Member
iTrader: (2)
 
Join Date: Aug 2008
Location: Richmond
Posts: 117
Total Cats: 0
Default

Is anyone having to run a restriction on the map sensor feed. I forgot that i have one on my gauge to clean up needle shake. I see a similar problem in the logs, where the pressure will spike for no apparent reason.
Mikeymx5 is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Another Cast Manifold Corky Bell Prefabbed Turbo Kits 18 11-22-2016 10:01 PM
Mazdaspeed 2.0L C-Spec ITB motor w/ accessories graexodus Miata parts for sale/trade 9 10-25-2015 04:34 PM
Are my coils failing? viriiguy General Miata Chat 5 09-28-2015 08:39 PM
In what world... curly MEGAsquirt 11 09-22-2015 12:54 PM
Worm drive clamps are better than t-bolt clamps aidandj Insert BS here 80 09-18-2015 08:19 PM


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 08:23 AM.