Fuel Injectors
 

Got some questions about getting fuel injectors. First off.. is it worth it?... I was thinking about putting 24lbers in my cobra when I go to clean off my gunked up IMRC's. I figured since I'm there Ill probably need to clean/replace my fuel injectors.
Also.. wuts all this im seeing about "not to be used with stock MAF" and that i gotta reprogram the ECU to support them?
I didnt think going from 19 to 24 would be such a big deal? is it?

:confused: ... :helpsmili

If you arent adding a power adder, leave them alone.

ya should get some more power from them...

i think ya'll need a new maf and that should be it... idk w/ yer year tho ya may need a tune or programmer idk

ive actually heard from some other people who have the same car as me that our MAF is pretty good as it is.

Idk i tihnk im leaning towards just getting some new 19 pounders or cleaning off mine depending on how the o-rings are holding up

All 4V mustang's save the 03/04 Cobras have 24 lb injectors stock. 4V 03/04 S/C Cobras have 39lb injectors.

Unless you've got a power adder or a Max effort built n/a motor adding injectors will do nothing.

Also a common misconception is that a specific MAF meter is required to run a particular injector. This is not the case. Any MAF meter can be used with ANY fuel injector, the calibration is performed in the EEC, not in the MAF meter.

Clean the IMRC's and save your money.

Philip K.

thats wierd cause when i was lookin at dif MAF they had different ones for 19 than 24 and so on...

why would they do that if its not necessary?

also is it the same w/ the 5.0?

The MAF transfer function and injector file is altered/inputed in the vehicles computer. It doesn't really have anything to do with the meter. Basically only purchase Ford Factory (OEM) meters, Cobra, Lightning etc. or SCT BA2400 or 2800 (I believe those are the part #'s) meters. These meters don't alter the resistance of the wire element in the MAF, which is the only reason Pro-M and those other MAF's made more HP is because they leaned out the A/F providing a false reading to the Vehicles computer. A MAF will typically not give any HP gains, even if larger in size...unless it is the point of restriction in an intake tract. It only extends the MAF range so you don't peg the meter. (i.e. in boosted applications)

Philip K.

I've always heard to leave you MAF and injectors alone unless you were making some pretty good hp...

MAF's are calibrated by some companies, meaning that someone flow tests them and notes what voltage they output for a particular airflow. That's it in short and minus all the cool detail.

Once you have a flow sheet for your MAF, then all that data can be put into the tune to make it more precise. 96-01 had meters that you could fool by changing the size of the sample tube but that yeilds a lot of issues you shouldn't have to deal with in hardware. Ford made an upgrade to the MAF (if you want to call it that) in 02-04 GT's that moved the IATS to the MAF body from further up the snorkel. So yes, you do need to adjust for larger injectors, by telling your ECU that it's now controlling larger ones. It'll change the pulse width and that will keep you from flooding the motor.

Other methods of calibrating a MAF would be to alter the resistance of the filament wire that is being heated in some precise way and documenting the voltages required to heat the wire for particular flow. These MAF calibration exercises are really a legacy from trying to keep cars with big blowers from pegging their MAF at high boost levels.

Lastly, yes 97stanger is correct in principle. You shouldn't consider tinkering with your MAF or injectors until you begin running close to the border of the duty cycle they can provide. On 02+ the MAF is 80mm and the injectors are 21lbs... any bigger is not useful until you see boost.

<flame suit on>

alright thanks for the info... i guess ill keep the stock 19 pounders but id definitley like to go ahead and clean them... any suggestions on how to go about doing this? or should i just replace them?

For stockers... i'd just replace them. It's not too pricey and you'll have a spare set that way.

I'm not certain that your cobra came with 19's though... I though 4V's came with 24's. You may want to verify. Call a mustang shop and check.