Fuel injectors: 2-hole vs. 4-hole

[Loudgoldwing]

OK, so the factory original fuel injectors for my AFC engine were an "A" designated nozzle, 2-hole aerator. Then, somewhere along the line, somebody developed the "E" designated 4-hole aerator... and these E-series 4-hole nozzles are what are now considered "factory replacements." My '98 cabriolet was running a little rough at 70,000 miles, so I bought and installed a remanufactured set of what were advertized to be OEM injector nozzles. Installed them, and the car runs great. The nozzles I installled were A-series 2-hole nozzles. Oddly though, the nozzles I removed were the NEWER E-series 4-hole nozzles. Like somebody installed the new ones after the recall a few years ago. What is the difference between the original 2-hole model and the updated 4-hole model? Obviously, 2 additional holes... but functionally speaking, does anybody know the specifics? The main reason I ask is because it feels like even though the nozzles I have in there now are of an older generation, they feel like a better match for the injection profile of my ECU. My idle is smoother. My acceleration and shifting are cleaner. My fuel economy is higher. So, I'm thinking two things: 1) I'm assuming that my removed E-series nozzles are worth cleaning and re-ringing. But I don't know how to clean the innards, as it looks like you need to hook them up to a power source to get them to "open" in order to shoot cleaner in to them and get the sludge inside to dissolve; and 2) I'm wondering if, even after cleaning, I re-install the E-series 4-holers the car might feel sluggish again. If so, is it because whoever installed the newer nozzles failed to re-configure the ECU to compensate for the different spray-pattern? If any of you guys has any experience is dealing with the differences between these two models of injector nozzle, I would be grateful to learn from you.

[Lago Blue]

I don't have any direct experience on 2 vs 4 hole injectors that are specifically 12v, but I am interested to hear more. However I do have what I think are Bosch 4 hole-er's (Chevrolet OEM?) on my I-5 20V (part of a Patrick Carlier kit, now sold by 034 Motorsport) and love them. Because these two engines are so similar, I have wondered about the specs for these vs the OEM 12V injectors, and if one could install the 5 from that kit (plus one injector) or something sharing it's specs, in place of the 12V OEMs. My I-5 kit has earlier(?) more economical(?) grey (vs red or black in more recent 034 kits) injectors IIRC (see attached photo).

http://www.034motorsport.com/fuel-in...ved-p-329.html

I have had good experience with the old 12V OEM injectors I'd sent to RC Engineering for their basic, reasonably priced and quick; cleaning, balancing and calibration (standard) service.

http://www.rceng.com/Fuel-Injector-Cleaning-P43C0.aspx

My experience was that freshened; even old injectors from the wreckers, where certainly better than my "original" (post-recall) dirty ones.

I'd suspect that a Bosch 4-hole nozzle is a newer design than a Bosch 2-hole. I'd also suspect that it's got 2 more (and more expensive?) holes for a reason. However, I'm guessing. This may be the evolution of the Bosch style injector alone, and other types with different hole numbers may be as good. For instance Mance and others certainly sound pleased with their RC Eng./Lucas narrow focused, less than OEM spec injectors which have who knows how many holes; one perhaps?.

Anyhow, it would make an interesting comparison, fresh Bosch 4 vs 2 hole-er's. Do more holes mean greater atomization?

When one orders injectors at the dealer, does one get 4-hole-ers automatically (normal super-ceded part procedure)?

Is the "A" or "E" designation part of the part number?

[LandCruzer94]

I have an e28 BMW that used older bosch 2 pintle injectors, but a factory "upgrade" common with a bunch of guys use is a set of 5.0l mustang injectors. It's the same impedance, but 4 holes. The only thing different is the spray pattern, which better atomizes the fuel for a more efficient, even burn.

[rn4thbrdr14]

is that link to 034 motorsports the exact injector setup needed for the 2.8 12v v6 motor

[Lago Blue]

Please read my post again and count the number of injectors in that kit. I simply thought it would be interesting.