LESS THAN 9.5 MPG CITY DRIVING!!!

[Mustang5L5]

stock A9L ECU, the MAF is a 70mm Crown Vic for 29 lbs injectors.

What's the MAF part number on the electronics?

If its F2VF-12B579-A2A, those work with 19# injectors. If it's anything else, it will not work with the A9L without tuning. Factory OE Maf's are not "calibrated" to injector size. They output a transfer function that the ECU interprets and converts for injector size. The F2VF-12B579-A2A MAF just happens to have a similar transfer function to the OE E9/F1 Maf so it works, but anything else will not.


I actually run the F2VF-12B579-A2A 70mm MAF on my combo with an untuned A9L and 19# injectors and it still runs rich. If you are running larger injectors, it's probably VERY rich.


EDIT: now that i go back and reread, sounds like the 29# was a typo and you meant 19#

 

[PonyGTrider]

A new set of plugs may be needed, what are you running now?

I’m running autolites 24 set to 0.054” Snd they’re only a few hundred miles old

Thank you

 

[PonyGTrider]

What's the MAF part number on the electronics?

If its F2VF-12B579-A2A, those work with 19# injectors. If it's anything else, it will not work with the A9L without tuning. Factory OE Maf's are not "calibrated" to injector size. They output a transfer function that the ECU interprets and converts for injector size. The F2VF-12B579-A2A MAF just happens to have a similar transfer function to the OE E9/F1 Maf so it works, but anything else will not.


I actually run the F2VF-12B579-A2A 70mm MAF on my combo with an untuned A9L and 19# injectors and it still runs rich. If you are running larger injectors, it's probably VERY rich.


EDIT: now that i go back and reread, sounds like the 29# was a typo and you meant 19#

The electronics I have is F2VF-12B579-AA
And you’re right I meant to write 19 lbs, I corrected my post.
I read that the best sensor is the one ending with A2A. People tuning the one I have (AA) assure they have some idle and other issues. I don’t know if you’ve experienced those issues yourself or if those rumors are true.

Thank you for all your help

 

[TOOLOW91]

Thank you for the time,
Like I said stage 1 cam stock A9L ECU, the MAF is a 70mm Crown Vic for 29 lbs injectors.
In relation to the O2 sensors I haven’t physically checked their function, I’m just relying on the info from the ECU that they’re working properly.

Testimonies like yours tell me that my engine is completely out of tune

Thank you much

What brand maf is it ? Who’s 70mm if it a stock maf in one of to see calibrated deals . Toss it .

Have those 19lb injectors flowed and cleaned make sure they are good . I’d get a pro m maf if you plan on keeping it a 70 mm. The transfer function will be more accurate in my opinion .

You need to see if the 02 are trimming fuel or if the ecu is just using default values because they are no good .

All of this together will make a Huge difference . Give it the timing back if it likes it to .

 

[General karthief]

When I said drop the timing I meant just a couple degrees but you can start at base and bump it up a couple degrees at a time, mine seems to like 13*.

 

[Bullitt347]

What is your tire pressure set at?
Are the brakes dragging? To check that raise the front end and roll the tire, it should turn over fairly easily, same for the rear, but both rear tires need to be off the ground and trans in neutral. Also the alignment should be checked.
Those 3 things would add up to 1-4 mpg depending on how out of wack they are.

 

[Kid wita 5oh]

I’m running autolites 24 set to 0.054” Snd they’re only a few hundred miles old

Thank you

Tfs head should run a 3924 plug not a 24 ... completely wrong plug... Change em out and see what happens

 

[Kid wita 5oh]

24

3924

 

[PonyGTrider]

What is your tire pressure set at?
Are the brakes dragging? To check that raise the front end and roll the tire, it should turn over fairly easily, same for the rear, but both rear tires need to be off the ground and trans in neutral. Also the alignment should be checked.
Those 3 things would add up to 1-4 mpg depending on how out of wack they are.

Thank you for your response.
My tires are at 36 psi and I can roll the tire effortless while the car is o suspendes. No dragging brakes at all

Thank you

24

3924

i thought they were the same
I will pull one out of there and verify that.
Before I was running NGK FR5 and had the same lowly MPG .

I’ll double check that. Thank you

 

[PonyGTrider]

What brand maf is it ? Who’s 70mm if it a stock maf in one of to see calibrated deals . Toss it .

Have those 19lb injectors flowed and cleaned make sure they are good . I’d get a pro m maf if you plan on keeping it a 70 mm. The transfer function will be more accurate in my opinion .

You need to see if the 02 are trimming fuel or if the ecu is just using default values because they are no good .

All of this together will make a Huge difference . Give it the timing back if it likes it to .

The MAF tube and sensor came out of a Crown Victoria and are ford with 19 lbs injectors. I made that swap as an upgrade. My injectors are completely serviced and clean.
I must test the O2 sensors or just replace them, probably they are at the end of their useful life, they avent triggered any error codes but they probably are not as efficient as they should.

Right now the 10 degrees base timing is so boring compared with the 15 degrees I had it few days ago.

Thanks man for your ideas

 

[PonyGTrider]

I’m running autolites 24 set to 0.054” Snd they’re only a few hundred miles old

Thank you

Actually I'm running Autolites 3924, I just removed one of them and they are not 24's. Sorry

 

[Kid wita 5oh]

How do they look?

 

[PonyGTrider]

How do they loo

How do they look?

 

[PonyGTrider]

 

[PonyGTrider]

I think your car needs a tune, the MAF cleaned, new 02 sensors, or all three. Your combo should not be netting you carbed big block drag car fuel economy.

I keep the MAF very clean. Every time I clean the MAF sensor I unplug the battery to start with fresh parameters. The O2 sensors are old but never triggered any error code on the ECU but I guess I will replace them to eliminate that possibility.
Thank you

 

[AeroCoupe]

All the parts you have should work well together. When the cam was installed was it degreed? Valves adjusted properly? Have you checked for vacuum leaks? Verify the mechanicals as the ECU can only compensate for so much and you are throwing the kitchen sink at it.

 

[PonyGTrider]

Thank you

All the parts you have should work well together. When the cam was installed was it degreed? Valves adjusted properly? Have you checked for vacuum leaks? Verify the mechanicals as the ECU can only compensate for so much and you are throwing the kitchen sink at it.

,
The cam was not degreed, it was installed dot to dot. My magnums have a quarter of a turn after zero lash. I have tested many times for vacuum leaks and I have none. Sincerely I don’t see anything mechanically wrong it is just wasting fuel with no apparent reason.
I will replace the O2 sensors and see if things get better.

 

[TOOLOW91]

Thank you

,
The cam was not degreed, it was installed dot to dot. My magnums have a quarter of a turn after zero lash. I have tested many times for vacuum leaks and I have none. Sincerely I don’t see anything mechanically wrong it is just wasting fuel with no apparent reason.
I will replace the O2 sensors and see if things get better.

Not saying this is the case for yours but I had mine in retarded 2 degrees . I have the sheet somewhere but that’s where it ended up degreeing At .

Put the ignition timing back in it for sure

 

[PonyGTrider]

Not saying this is the case for yours but I had mine in retarded 2 degrees . I have the sheet somewhere but that’s where it ended up decreeing At .

Put the timing back in it for sure

Oh ok I understand what you said
Thank you

 

[Bullitt347]

When was the last time the fuel injectors were cleaned?
And that does not mean pouring some "cleaner" in the gas tank.