24 lbs injectors to much 4 stock computer?

lee888

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Jul 20, 2006

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Jul 23, 2006

#1

• Jul 23, 2006

• #1

holley systemax intake and plenum,70 mm tb,24 injectors,70 mm maf,egr delete,adjustable fuel regulator,255lp fuel pump.running rich till about 3500 rpms,sputtering,doggin out,gutless.at 3500 starts to clean up and go.i heard the stock computer cant adjust it right.new o2 sensors,cleaned iac,tps set correctly,timing correct,plugs,cap rotor all new.any ideas?need a computer tune?chip?24 lbs injectors too much?never heard of this.thanx

 

T

TheUser

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Jul 25, 2003

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Springfield, MO

Jul 23, 2006

#2

• Jul 23, 2006

• #2

Is your maf calibrated for the 24 lb injectors? The computer uses the signal from the maf like a multiplier, so you must get a MAF calibrated for the 24's, or some may be recalibrated.

Also, what is your fuel pressure set at with the vacuum line pulled off of the adjustable fuel pressure regulator?

 

Black1987Stang

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Aug 22, 2004

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Jersey Shore

Jul 23, 2006

#3

• Jul 23, 2006

• #3

Yeah 24lbers are no prob for the computer, mine had a similiar problem, pull ur codes n see what u get.......I would check ur maf (clean) (has to be calibrated for ur size injectors also), Engine coolant temp sensor, and throttle position sensor, thats what im thinking of anyways.......pull the codes anyways n see what u get

 

lee888

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Jul 20, 2006

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Jul 24, 2006

#4

• Jul 24, 2006

• #4

i was told when i bought it,the maf was 24 lbs calibrated.i swapped it with one that was 19 lbs and neither engine changed.i also swapped the tps,did not change either.where can i find a computer code reader for an 89?nobody seems to have one except anderson motorsports at 900 bucks?also set the tps at .95.thanx for the info guys

 

lee888

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Jul 20, 2006

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Jul 24, 2006

#5

• Jul 24, 2006

• #5

oh yeah,the fuel pressure is at 44 right now.i was told to start at 38 and go from there.i will still be experimenting thogh to see what is best.thanx again

 

srothfuss

Last night I stabbed the same guy 7 times in a row

Oct 17, 2004

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Woodward Ave.

Jul 24, 2006

#6

• Jul 24, 2006

• #6

Stock fuel pressure should be right around 38 - 39PSI. I would reset that and then try again. If you still retain your EFI and sensors, you can use the EEC to help diagnose any engine problems. If you need to, I can link you to a post that explains the process

 

sunil6784

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Jul 24, 2006

#7

• Jul 24, 2006

• #7

You can find a code reader at autozone or some walmarts. I found mine at walmart for 30 bucks.

 

grey5.0beast

Cookies should never be DUNKED!!!

Aug 3, 2004

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atl ga

Jul 24, 2006

#8

• Jul 24, 2006

• #8

I have a reader from pepboys, has wires for almost any car, including most imports and all domestics. I think somewhere from 2- 300. Comes with all of the cables. I just pull the code and google the code to find out what it means. Or u can hook it up to a usb cord for the comp and download software, but its pricey, I haven't tried limewire, might be a good idea.

 

lee888

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Jul 20, 2006

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Jul 24, 2006

#9

• Jul 24, 2006

• #9

thanx guys.i will pick one up and run the codes.i adjusted the pressure in small increments till 44,did not fix the dogging.ran better,still not right.get the codes and finger it out from there.thanx again.

 

ninety15.0

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Mar 10, 2004

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Jul 24, 2006

#10

• Jul 24, 2006

• #10

what kind of MAF is it?

 

lee888

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Jul 20, 2006

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Jul 25, 2006

#11

• Jul 25, 2006

• #11

i am not sure.it was ebay buy.it is 70 mm ,was told calibrated for 24.how can i check that?the calibration?

 

vristang

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Mar 31, 2005

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Jul 25, 2006

#12

• Jul 25, 2006

• #12

What is the part number on the MAS? (I am assuming the MAS came with the MAF tube)?

It should be F1SF or F1ZF or something similar.

It sounds like you have a cobra cobra MAF, or a unit for a later mustang/crown vic/etc.

Have you measured the ID to confirm the 70mm dimension?

 

lee888

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Jul 20, 2006

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Jul 26, 2006

#13

• Jul 26, 2006

• #13

the numbers are f4sf-12b579-aa then an al20 in a box below it.which part says the lbs calibration?

 

lee888

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Jul 20, 2006

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Jul 26, 2006

#14

• Jul 26, 2006

• #14

ha,just measured the id.it is 80 mm.i was told 70 and 24 lbs.the id is 80 so the 24 could be wrong too.how can i find a chart of maf numbers to correspond with?

 

vristang

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Jul 26, 2006

#15

• Jul 26, 2006

• #15

Is there any taper to the ID of the tube?
Can you measure at the test section (toward the middle of the tube)?
Many will flair out at the inlet and outlet.

Here is a site that lists stock maf's and their applications by MAS and tube diameter.
http://rothfam.com/svo/reference/maf_part_number.html

I see a 94-95 4.6L T-Bird that uses a F4SF MAS and a 70mm tube with 24lb injectors.

How certain are you that this is a stock Ford MAF tube?
Can you post a pic?
It is crucial to ID this thing before moving on.

IF IT IS A STOCK MAF -
The stock MAF meters were not "calibrated" for the injector size the way aftermarket meters are. Instead Ford changed the injector setting in the computer. What this means is that a MAF from a Ford vehicle with 24lb injectors will not work on a fox computer with 24lb injectors.
If you are using an aftermarket tuner then you can dig into the Ford computer and make the injector and MAF Transfer changes. Burning a custom chip will work as well.

jason

 

F

FullAuto

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Aug 29, 2002

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Jul 26, 2006

#16

• Jul 26, 2006

• #16

I hope they aren't too much for the stock computer. I've had 60lb injectors in for 2 years now with my stock A9P.

 

lee888

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Jul 20, 2006

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Jul 29, 2006

#17

• Jul 29, 2006

• #17

There is very little taper to the ID, but it does taper. I am not sure if it a stock one, I bought it off ebay and they did not have any idea. there are no markings on it that tell me what brand. Just told, calibrated for 24's. When I put it on my 91 w 19lb injectors, accelerates better, but my 89 with 24's does nothing. Pics are too big to post, any other ideas?

 

vristang

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Jul 30, 2006

#18

• Jul 30, 2006

• #18

lee888 said:

There is very little taper to the ID, but it does taper. I am not sure if it a stock one, I bought it off ebay and they did not have any idea. there are no markings on it that tell me what brand. Just told, calibrated for 24's. When I put it on my 91 w 19lb injectors, accelerates better, but my 89 with 24's does nothing. Pics are too big to post, any other ideas?

Click to expand...

If there is no "C&L" marking cast into the tube, and the tube is Aluminum, then I think it is a stock MAF.
This is not something we should take guesses on though, as very minor differences in MAF output can cause major problems.
If your photo viewer does not allow you to resize the photos then you can email them to me.
jason.c.willard@gmail.com
I will take a look and possibly post them here.

In order for a MAF/Injector/Computer combination to work, all three of these things must be "calibrated" as a system.

jason

 

LEE93COBRA

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Jul 30, 2006

#19

• Jul 30, 2006

• #19

If it has a ford part # then it will not work. You need to either get a 93 cobra EEC or get a brand name MAF that you know has the right fuel injector sample tube in it.

A MAF is not something you can cheap out on. You have to know what you need and more importantly, know what you are getting.

 

lee888

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Jul 20, 2006

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Jul 30, 2006

#20

• Jul 30, 2006

• #20

that sucks.no c l stamps.no markings at all other than ford numbers and ford logo.looks like i need a maf.what is a good brand?this was 1rst ebay i got jacked on.a 24lb maf of good brand.ideas?thanx a bunch.