Right size injectors?

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primerdnoma

New Member

May 18, 2008

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Sep 4, 2010

#1

• Sep 4, 2010

• #1

My car had an Eaton M90 on it with 30lb injectors...but I couldn't get it running right with it and don't have the money to tune, so I got an insanely cheap hook up on a cobra intake with BBK TB. Here's what I have:

Rebuilt motor with redone heads, stock
FRPP B303 cam
BBK adjustable FPR
30lb injectors
Cobra upper and lower intake
BBK 70mm TB
Ligntning MAF
Mac shorties
Off-road H pipe

Now, the car seems to run OK at mid-high RPMs but it has a bad hesitation when first getting on it, idles OK too though. It has to be pushing way too much fuel for what the setup is now...can I lower the FPR a reasonable amount to only be pushing 22-23lbs or do I have to step down to smaller injectors? Is the MAF OK or am I going to have to switch back to a stock unit, or say a Vortech one?

 

Mustang5L5

That is…until I whipped out my Bissell

Mod Dude

Feb 18, 2001

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Massachusetts

Sep 4, 2010

#2

• Sep 4, 2010

• #2

Does your car have a tune for the 30lb injectors? Of are you running a maf calibrated for 30lbs? The lightning maf is not plug and play. You need a tune

 

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primerdnoma

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May 18, 2008

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Sep 4, 2010

#3

• Sep 4, 2010

• #3

No tune, and that pretty much just answered my question...I thought Lightning MAFs were for 30# injectors, guess they're for 42#ers. I'm picking up stock injectors and a stock MAF in a couple days. What would be the right size injectors for my setup? If I run stock 19# ones and up the psi to say 45 would that be good enough for what I have?

 

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885ive.0

New Member

May 18, 2010

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Sep 4, 2010

#4

• Sep 4, 2010

• #4

The stock 19# injectors are plenty good enough for ur setup they are good up to like 375hp which u are well away from but i would recomend u finding a bigger maf calibrated for the stock injector cause the stock maf sucks its a big restriction but if its all u got at the time ru it till u find one

 

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primerdnoma

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May 18, 2008

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Sep 5, 2010

#5

• Sep 5, 2010

• #5

I'm looking at picking up a Vortech MAF then, 73mm. I actually just ran the part number on the MAF I have now, and it's a stock 89 TBird SC MAF, which is for 30# injectors but it's only a 55mm. Damn at this point I should have just kept the blower on haha...oh well, I'll get it running like this now then fab a new upper intake to fit the blower to the cobra lower.

Do you think pushing around 7psi with the blower, that 30# injectors are too big for that too?

 

Mustang5L5

That is…until I whipped out my Bissell

Mod Dude

Feb 18, 2001

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Sep 5, 2010

#6

• Sep 5, 2010

• #6

The problem is oem mags are not calibrated. They have an internal data table that the EEC interprets and translates for the injectors the EEC is programmer for.

There are only a few mafs the mustang computer will work with...and a t bird maf is not one of them.

A 94/95 sn95 maf is 70mm and will work with the mustang computer and 19# injectors. You will need an adapter aswell.

The t bird maf will require tune.

If you want to use the 30's you need an aftermarket maf for 30's or a tune.

For your combo...19's are fine. Use use the 70mm sn95 maf. There is a thread on here showing how to make it work on the fox

 

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primerdnoma

New Member

May 18, 2008

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Sep 5, 2010

#7

• Sep 5, 2010

• #7

Ok that makes sense, and explains why the car wouldn't/won't run right with the current MAF. Definitely looking into that.

 

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cheese_05_70

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Aug 29, 2005

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IL

Sep 6, 2010

#8

• Sep 6, 2010

• #8

you still have the lightning maf, if so and you want to sell pm me.
thanks

 

2000xp8

SN Certified Technician

Aug 8, 2003

8,015

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NJ

Sep 6, 2010

#9

• Sep 6, 2010

• #9

30's should be good for the SC setup.
I'd put the SC back on, then add a PMAS meter or old pro m calibrated for 30's.
I bet the car runs significantly better.

Forget the 73mm meter.

 

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primerdnoma

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May 18, 2008

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Sep 7, 2010

#10

• Sep 7, 2010

• #10

I don't really want to put the SC back on just yet...the motor hasn't even been broken in, so I was planning on waiting a couple months if I even keep the car(I have a bad habit of trading).

I don't have a lightning MAF cheese, I was told wrong.

Now, I took the MAF off the car and measured it...it's about 3.25" so it's an either an 80mm or 83mm MAF housing with the tbird electronics in it. After I told my buddy who owned the car, the moron said OHHH YEAH I FORGOT I SWITCHED THE SENSOR INTO A DIFFERENT HOUSING. Here's some pics...there's no way that's a 55mm housing, he also made an adapter for it. I'm picking up the stock MAF for free tomorrow, can I just throw the sensor in this housing or will it not work that way?

 

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Mustang5L5

That is…until I whipped out my Bissell

Mod Dude

Feb 18, 2001

43,172

17,870

224

Massachusetts

Sep 7, 2010

#11

• Sep 7, 2010

• #11

Won't work that way. Sensors are not interchangeable. That maf is pretty much useless to you.

Get a stock maf and 19# injectors....or am sn95 maf

http://www.stangnet.com/mustang-forums/616246-94-95-maf-install-completed.html

 

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primerdnoma

New Member

May 18, 2008

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Sep 8, 2010

#12

• Sep 8, 2010

• #12

Awesome.. I love taking over peoples screw ups haha.

 

madspeed

Colonel Mustard

Founding Member

Nov 29, 1999

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a van down by the river

Sep 9, 2010

#13

• Sep 9, 2010

• #13

ALWAYS SEEMS TO BE THAT WAY HUH??