BC

I am only holding them open for a second at most, usually pulsing, on/off/on/off quickly by taping the leads on and off the metal electrical connections. When I pulse as quickly as I can, I hear about the same as what the idling "click" frequency is on the 928 and I see no real change. At high rpms, the injectors are at close to 90% duty or higher. That is almost on all the time.



Sorry to confuse with the pictures. I am essentially saying that the four streams LOOK like the 2 streams (but there are four). By saying this I mean its a stream of fuel instead of what I IMAGINED it to be, which was a fog of smaller droplets in a larger fan - like the other pic.

dcrasta

If you're using an adjustable FPR you may be too low on the rail .
Low fuel pressure will stream like a garden hose. 36psi on the rail or 55 should give you the pattern you want.
Dirty injectors are quiet and leak. Run seafoam and carb cleaner through them and check them with 36~40 PSI and re-evaluate.
You may want to rig a momentary switch so you can pulse them . If you hold them open (As someone else mentioned) the solenoid can burn up its a small one made to operate in short burst.

slate blue

If you have complaints about the 4 hole injectors you should see the single hole early euro injectors, just like a hose on a hard spray. Now because of this issue I bought motorcycle injectors some years ago now. This would require 2 injectors per cylinder which for you Brendan would not be an option due to the ethanol issue and compatibility and fuel flow volume.

RC injectors have better injectors than 4 hole injectors. Not sure how many holes but it could be about the same as one of my motorbike injectors which have 12 holes each. This means that I would have had 24 holes spraying and that would be fairly fine in terms of pattern. Direct petrol injection injectors could be an option? It would require a lot of work for a small return. They spray in more of a fog than a diesel. Most EMS systems can't run a direct injection system. Bosch aftermarket can, I don't believe Motec can, or they certainly couldn't. It is very top end expensive technology. I wouldn't go there myself.

BC

This test, for me, is to really see what is going into the car and to choose the best of what I have laying around, which is about 50 or so injectors, all just in a box. I have separated them and have set out to at least group them into batches of "usable" and "not usable"

24lb injectors on a stock engine with Ken's chips should be okay for my ethanol usage (I use it in all of my cars now - except my wife's acura). I have to turn up the fuel pressure and will need to turn up Ken's resistor for richness I believe. The more complex issue is that ethanol will act differently with reference to the "port wall pooling" phenomenon, and it could cause issues later on with the other cars, boost, and aftermarket ecus -

but I have digressed -

this is just for getting a cheap 85 on the road for DD duty. I have redone the top end and wish to put in the best used injectors I have.

But with your mentioning RC injectors - I am tempted to unbox the 75lb RC units I have in my desk drawer! See how those suckers look!

Maybe I will take some pics. For that I will need to employ the help of my 9 year old son to at least hold the camera.

BC

While there ARE methanol injectors, ETHANOL injectors are really not something that is normally a niche. E85 will flow just fine in normal petrol injectors, except that under increasing boost, you will need 40% more fuel flow.

soontobered84

So you used MC injectors? And they fit? Would you have the part numbers for those injectors? That would be interesting.

blown 87

Snap-On sells a injector test box, to power the injector.

slate blue

Normally everything I do requires custom fabrication, so no easy just drop them in unfortunately. So other than the idea, I can't help you, sorry.

Bill Ball

OK, it might be worth giving witchhunter a call. Perhaps the 4-holes you have are not correct for our application. The stock single hole S4 injectors throw a decent spray pattern due to the center pin.

BC

The four holes I have are the normal ones everyone buys when they wish to replace the 24lb injectors in an S3.

I have some S4 injectors - I can try and test them as well.

danglerb

Want to test some more injectors?

Bill Ball

Yeah, Whitchunter's prices went up. How much do you want?

Speedtoys

THE $80/SET Mustang OEM injectors I got off Ebay 18mos ago, run great. Four hole...etc.


Bills' driven it.

soontobered84

I have used Cruzin' performance several times and been very happy. Richard seemed to be more responsive (to me).

BC

I have plenty here, thank you very much.