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Topic: Mass Air added, hesitation off the line (Read 7731 times) previous topic - next topic

Mass Air added, hesitation off the line

Reply #15 –
here is where i got the Maf,, was from Flipnbird

http://www.foxtbirdcougarforums.com/showthread.php?38259-mass-air-meter

Mass Air added, hesitation off the line

Reply #16 –
Quote from: jcassity;462221
also,, the car is *not* running like  either with the MK8 & 24lb injectors on the A9P eec

I think i mentioned the only issue is slight 1/2 second hesitation from idle to quick throttle.... like  a communications delay or something.

Anyway,,

pic of our maf coming up here in  a few.


99.999999% chance that is caused by the Mark VIII MAF. I guarantee it. Running the Mark VIII MAF without a tune will screw up a bunch of things with fuel control/load calculations. No matter what you do that Mark VIII MAF will not work without a tune.

Quote from: jcassity;462222
here is where i got the Maf,, was from Flipnbird

http://www.foxtbirdcougarforums.com/showthread.php?38259-mass-air-meter


I looked at that MAF. You need to find out if it's set up for the stock airbox or a conical filter clamped to the end of the MAF. They have slightly different flow curves depending on what is in front of the MAF. Most of the time a MAF like what you purchased is set up for the stock airbox. Most of the time.
88 Thunderbird LX: 306, Edelbrock Performer heads, Comp 266HR cam, Edelbrock Performer RPM intake, bunch of other stuff.

Mass Air added, hesitation off the line

Reply #18 –
Quote from: thunderjet302;462224
Also read this, all 3 sections: https://web.archive.org/web/20150225073218/http://www.cnlperformance.com:80/MAF_info.php?section=10

It'll help explain why all this stuff I'm talking about is important.

im going with your word on it,,, i trust your info.

I will ask Flipnbird about the air box but we do have either the stock air box or conical for more volume if required.

Q-  how do we know if i have a shaged up set up if its not running bad or throwing codes?

The mk8 maf & 24lb inj were not tossing codes and we were not rich

we are now installing this other PMaf from Flipnbird with his injectors (even though his and the mk8's both read 13.7ohms),


if it runs better how will we know especially when things seemed good before? except for that common hesistation even mentioned on the cobra EEC ford muscle complained about as well

Mass Air added, hesitation off the line

Reply #19 –
I had a bad MAF that was leaning out and causing a bad hesitation off the line. Didn't throw any codes but when I back probed the O2 sensors at the EEC harness you could see they were showing lean to the EEC. I swapped in another MAF and the issue went away. No codes were thrown in that case as everything was "in spec" but lean.

You shouldn't have to swap the injectors, just the MAF should be good.

Edit:

Ohming the MAF does nothing for you at this point. You'd want to back probe the MAF connector and see what reading (voltage) it's putting out at idle, 1000rpm, 2000rpm, 3000rpm, etc.

Also stop trying to use the Mark VIII MAF without a tune. The Mark VIII MAF will not work with an A9P without a computer tune, no matter what you do.

If it's running good the hesitation will go away. I'm running a calibrated MAF for 30lb injectors on an A9P and 30lb red top FRPP injectors, no tune. There is NO hesitation anywhere at any throttle angle.
88 Thunderbird LX: 306, Edelbrock Performer heads, Comp 266HR cam, Edelbrock Performer RPM intake, bunch of other stuff.

Mass Air added, hesitation off the line

Reply #20 –
@ jcassity.....Yes that pro-m mass air is for 24lb injectors. I had that whole set up(ported cobra, 24's) I sold you in my bird and it ran VERY well. The mass air was bought new and was only a couple tears old when i sold to you
88 sport,TW heads, comp xe270hr, cobra u/Tmoss ported lower, 65 mm throttle body, under drives,smog delete,
1.7 roller rockers, cai, k&n, bbk adj regulator, 76mm Pro-m,all MSD ign. MSD dist,18° base timing, 3g alt.1 5/8 ceramic headers, 255lph walbro, 2.5" h-pipe, flowmasters, silverfox valvebody, 3.73 gear,
http://i216.photobucket.com/albums/cc154/flipnbird/DSCF0185.jpg ( RIP : ( )

Mass Air added, hesitation off the line

Reply #21 –
Did you use the MAF with the stock airbox or a conical filter clamped to the end?

Depending on which way the MAF is set up jcassity will have to run it the same way.

This should resolve the issue.
88 Thunderbird LX: 306, Edelbrock Performer heads, Comp 266HR cam, Edelbrock Performer RPM intake, bunch of other stuff.

Mass Air added, hesitation off the line

Reply #22 –
It's possible to have the lag with a MAF that's correct for injectors and ECM, but wrong for application...

When the MAF ped the bed on the '95 4.6 Bird we had a few months I installed a stock one for '92 Stang, idled fine, crused fine but had the off idle stumble upon opening throttle... It eventually set a code, was so bad you'd swear it would die but never did, one from a similar year V6 Bird fixed it...

Mass Air added, hesitation off the line

Reply #23 –
If you're futzing around with calibrated MAF's, you are almost ALWAYS going to have a hesitation in a car with an automatic.  The MAF is a load sensor.  When you're using a calibrated MAF, you CAN get the fuel right, but it skews the load calc.  In EECIV, load is not percent load by default, and is instead VE.  Which means when your load is miscalculated, your spark advance is wrong.  You're under advancing. 
Additionally, unless the A9P has a chip of any kind where the Injector lo and hi slopes, breakpoint, and voltage offsets are altered for 24# injectors, and the MAF transfer function for the Mark's MAF has been substituted, it's never going to be right.  Beyond that, GT40 heads have different knock characteristics, so your spark base table need to be altered as well as the sea level table and the altitude table (if you aren't setup to disable them) or you're going to get spark knock; especially in high ambient temps.

Mass Air added, hesitation off the line

Reply #24 –
Another issue is the Ford EEC IV's were not designed to run on fuel with 10% ethanol.  They only have about +/- 12.5% adaptive control and they max out fairly quick when folks add on the bolt-ons and then add in the lack luster fuel we have now.  Anymore the best thing to do is get a tune or buy a tuner and get proficient with a wide band O2.

http://www.veryuseful.com/mustang/tech/engine/EECIVInnerWorkings/

83 351W TKO'd T-Bird on the bottle


93 331 Mustang Coupe - 368 rwhp

Mass Air added, hesitation off the line

Reply #25 –
One of the first things I did about that in my tune is to set the adaptives for max LTFT (KAMRF) from .850-1.15 to .750-1.25 and gave the same range to my STFT (LAMSE).  Makes the car a bit more forgiving of my fuel choices.

Mass Air added, hesitation off the line

Reply #26 –
I had this ran with a cone filter on the end inside the passenger fender well...
88 sport,TW heads, comp xe270hr, cobra u/Tmoss ported lower, 65 mm throttle body, under drives,smog delete,
1.7 roller rockers, cai, k&n, bbk adj regulator, 76mm Pro-m,all MSD ign. MSD dist,18° base timing, 3g alt.1 5/8 ceramic headers, 255lph walbro, 2.5" h-pipe, flowmasters, silverfox valvebody, 3.73 gear,
http://i216.photobucket.com/albums/cc154/flipnbird/DSCF0185.jpg ( RIP : ( )

Mass Air added, hesitation off the line

Reply #27 –
Yeah, that will make a HUGE difference in the way the MAF  reads. The really serious outfits that provide calibrated MAFs will provide a different MAF sample tube for cars with open cone filters.

Mass Air added, hesitation off the line

Reply #28 –
Quote from: flipnbird;462257
I had this ran with a cone filter on the end inside the passenger fender well...


With a bend in front like a cold air intake or with the filter clamped to the end of the MAF and the MAF and filter both in the fenderwell?
88 Thunderbird LX: 306, Edelbrock Performer heads, Comp 266HR cam, Edelbrock Performer RPM intake, bunch of other stuff.

Mass Air added, hesitation off the line

Reply #29 –
Quote from: TheFoeYouKnow;462246
If you're futzing around with calibrated MAF's, you are almost ALWAYS going to have a hesitation in a car with an automatic.  The MAF is a load sensor.  When you're using a calibrated MAF, you CAN get the fuel right, but it skews the load calc.  In EECIV, load is not percent load by default, and is instead VE.  Which means when your load is miscalculated, your spark advance is wrong.  You're under advancing. 
Additionally, unless the A9P has a chip of any kind where the Injector lo and hi slopes, breakpoint, and voltage offsets are altered for 24# injectors, and the MAF transfer function for the Mark's MAF has been substituted, it's never going to be right.  Beyond that, GT40 heads have different knock characteristics, so your spark base table need to be altered as well as the sea level table and the altitude table (if you aren't setup to disable them) or you're going to get spark knock; especially in high ambient temps.

You know oddly enough my car with 30lb FRPP redtop EV1 injectors and a 76mm C&L MAF calibrated for them runs great with no tune. No hesitation, no knocking, nothing. I run 16* base timing SPOUT out and 93 octane Shell gas. Runs just as good or better than my '12 Mustang or '17 Accord.

Is it the best way? No but it gets me by. I plan on getting a better MAF and a tune next year (was going to do that this year but blew all my car money on body work :hick:). I'm hoping it's worth the cost and I pick up a couple HP.
88 Thunderbird LX: 306, Edelbrock Performer heads, Comp 266HR cam, Edelbrock Performer RPM intake, bunch of other stuff.