Different years and injector models.

[Unexplodedcow]

Was finally putting the stock '10 manifold back on with the CMCV delete after plugging the back holes a little better (and replacing a hose that leaked).

I had been using an '07 stock manifold in the interim. It came with Injectors but I never paid attention to the differences.

The stock '07 injectors are black fomoco parts. CM5183 is listed as the replacement for 05-10 4.6L 3V engines.

However, my car came with purple fomoco injectors, and motorcraft part CM5159 is specified for 09-10. Weird. They obviously swap and aside from a different tip shape, and looking up specs, it seems that the purple ones may have a different spray pattern. They are only spec'd for the Mustang GT for 2 years, or Explorer sport.

Had not found much info on this and wondered why the switch.

 

[StockishS197]

If they are the purple six hole injectors, then they should be the LU24As which I think came stock in 09+ https://performanceparts.ford.com/part/M-9593-LU24A

While many places say they are plug and play replacements, Ford does provide updated injector pulse width specs to make full benefit in the tune - FYI.

Edit: missed the part where you mentioned CM5159 - looks like the flow rate is a little less than the LU24As so disregard my comment above, though the six hole design should be an improvement over the previous 2 hole.

 

[GriffX]

Hold on, Ford changed the injectors for the 4.6 "final revision" to 6 hole injectors from before 2?
I'm wondering why. I can think of bad atomization on the closed half of the CMV and thinner holes can help, but the whole intake has been changed too.
Can they be used on older cars and do one need a tune for it?

 

[StockishS197]

Hold on, Ford changed the injectors for the 4.6 "final revision" to 6 hole injectors from before 2?
I'm wondering why. I can think of bad atomization on the closed half of the CMV and thinner holes can help, but the whole intake has been changed too.
Can they be used on older cars and do one need a tune for it?

They look to have the same body as the LU24As, so probably plug and play even with the older intake manifold.

To know for sure if you can run the CM5159s without a tune, would need to find the injector calibration data. Ford publishes the injector calibration summary for the LU24As and a tune update is required (though many vendors sell as plug and play without a tune).

When I went to the LU24As which have the same design as the CM5159s, I noticed a smoother idle and the car overall seemed more responsive.

 

[Unexplodedcow]

Thanks for the info @StockishS197 !

Yep, all purple, and likely the LU24A as they're stock to the car. The older ones from the '07 manifold were all black pieces. The bottom pintle area was different - the black ones are more conical inside with a smaller plastic surround, while the purple ones had a taller/larger plastic surround and the bottom looked more like a flat plate, not conical.

I wonder if the canned tune took into account the injector difference; it wasn't specified, though the year was. One of these days I'll get around to datalogging and making/getting a more appropriate tune. Another log in the fire.

Interestingly, the LU24As had thinner O-rings on them originally, too, though regular size rings fit. Don't know where those came from, as they were original to the car. I still have 'em sitting around.

 

[GriffX]

When I went to the LU24As which have the same design as the CM5159s, I noticed a smoother idle and the car overall seemed more responsive.

That's what I would expect, low and mid load operation can/should be better.

Found this regarding tune. https://eectuning.org/forums/viewtopic.php?t=21221

Aliexpress sell them for 120$

 

[StockishS197]

I wonder if the canned tune took into account the injector difference; it wasn't specified, though the year was. One of these days I'll get around to datalogging and making/getting a more appropriate tune. Another log in the fire.

Easiest way to tell if the tune accounted for them is to log LTFT and STFTs. If something is off fueling wise you will see it there.

 

[StockishS197]

Aliexpress sell them for 120$

If the LU24As on Aliexpress are legit, I got ripped off buying off local vendors for $250 lol

 

[GriffX]

STFT are only active during closed loop and correct the fuel-air mismatch. At cold start and WOT my guess is, that there is somewhere a fuel injector map (?)

 

[StockishS197]

STFT are only active during closed loop and correct the fuel-air mismatch. At cold start and WOT my guess is, that there is somewhere a fuel injector map (?)

There are fuel injector tables in the tune that affect any fueling state, open or closed loop. Basically just setting the pulse width timing for the commanded fueling.

Those have to be adjusted to the calibration specs stated by the manufacturer.

Edit: I just looked at the LU24As on my car and they have the same part number on the body as the CM5159s listed on RockAutos website, so I’m very confident they are the same injector, just sold under Ford Motorcraft vs Ford Performance (Racing).

 

[GriffX]

It looks like they are DENSO 195500-4821 stamped 9L3E-F7A on it.