Pic won't upload. IT's on my web server, but the webpage guy just reformatted the entire page layout, and all the links are whack now. Lets see here...



Holy ****, I guessed right at that on the first try. Anyway, here is the ecu side of the harness on an s4. You can see the 2 yellow ecu plugs at the end, and the 2 orange ones further up. The circled wires are the 2 power wires, which come from teh dash harness. They join together at the blue tape.

I found this out experimenting with a new, better, faster, shinier fuel cutoff switch for s4 cars with flooding problems. Instead of controlling the fuel pump (which has a delay and inconsistency) I hacked into this wire (power feed to all injectors) with my switch to directly control injector output while cranking. IT does work, and works well. A webpage writeup about this will soon follow.

 

All right...And the "aged" clear plug you have circled sits to the right of the ECU, up in there among the big cluster of wires?

 

It's not an aged clear plug, it's an orange plug from the factory. There are other clear plugs of the same age on that same harness, and they are still clear. Look at the pic. This is the firewall, there is no heat or sunlight to cause physical changes to these plugs.

Yup...right above the atmospheric pressure sensor.

 

Thanks bunches...learn something new every day...

 

I have already checked to see if spark was consistant through all the coils by puling off the wires. Thanks for the suggestion though.

Dont worry about it at all Wayne. You've helped me so much with totally understanding the problem and also how to fix and diagnose them.

RotaryResurrection
Thanks for being patient with me and helping me along the way. With that picture and the descriptions I should be able to find where the wires supplying voltage to the injectors split.

I will post back tomorrow after work and let you guys know how things go.

 

UPDATE:

After getting the new wire into the injector plug and trying countless times to get the DMM to read voltage, I finally took that injector plug and plugged it into the front primary injector. Magically a solid 12v is being read by the DMM without even putting the plug on all the way.

This leads me to believe my rear primary injector is fried/gone/broken. What I want to know is what exactly is wrong with the injector?

Also to confirm my assumption about the malfunctioning injector I tested resistance through all the other injectors at got a healthy 14.5-15.x volts on all the others. The malfunctioning injector didnt even make the DMM fluctuate at all. Looks like I did all the wiring in vain (guess that is a matter of opinion though).

Input/feedback welcome.

I guess it's 720's here I come!

 

We all assumed your injectors were good because you (I think) claimed they had just been cleaned/checked. Was this an invalid assumption?

 

Also I just realized something my injectors are red denso's but according to Kevin Lander's page on injectors http://www.rotaryresurrection.com/ro.../injector.html I am supposed to have purple injectors since I have an s5 TII. I cant see/read any parts numbers on them but here are some pictures.







Does this mean I have 460 NA injectors? RC engineering injectors? Denso replacements in red?

 

I never had the injectors cleaned myself, but ASSUMED they were since this engine was rebuilt not too long ago.

 

Stan, if all 4 of your injectors are the same, and both secondaries read out good, put one of them in that primary spot for now, unless you want to wait for the new ones. Just don't romp on her too much until you get the "bad" one in the secondary position now fixed...
That way you can at least drive the car to see if the problem is fixed...

 

I thought about doing that Wayne but I think I'll wait for the 720s. Can anybody explain the red injectors I have?

Also how can I depressurize the fuel system without putting everything back together and starting the car and pulling the fuel pump relay?

 

Don't know about the injectors, they look like mine (460's), but it's hard with those pics...

To depressurize, pull the inlet hose (from the filter) off of the rat's nest nipple, with a rag or bunch of paper towels wrapped around it, or if it would be easier, just pull (twist) an injector out of the rail with a rag, etc... wrapped around it. Extinguish all smoking materials first!

 

Yes, s5 turbo injectors are a burgundy/plum/purple color...just by the photo (which can be decieving, especially on a computer monitor) those look more reddish like an NA. You will NEED to find the part number...it would be 2020 for a turbo injector.

About depressurizing the rail, you don't HAVE to do that. Just have a shop towel under the injector and pull it out of the rail...use the towel to catch drainage, there isn't much of any pressure still in the rails after the car shuts off. It is always a good idea to protect your eyes in case of splashing though.

Take out the bad injector...apply 12vdc to it, and see if it clicks. You can actually feel it. IF you have a source of compressed air, you can hook that directly to the injector's inlet, turn on about 50psi to the hose, trigger the injector with voltage, adn see if air comes out the other end or not.

You can do the same test with the fuel supply line as well (with a cup or jug to catch the spray, obviously). To trigger the fuel pump, turn your key to ON, and bridge the yellow test connector by the pass. strut tower. IF you go this far, you can flow test your injector...use a measuring cup in mL or cc (the same measurement) and time the output for 30 seconds, multiply by 2 for total volume.

 

UPDATE:

Last night I pulled the fuel rails and all injectors. Inspected all of them and they are in fact S5 TII injectors with the 2020 P/N. I thought they were a faded red due to the heat exposure. The o rings were still in pretty good condition as well.

I test each injector with 12vdc and a ground and all of them clicked except the rear primary. So what is actually defective about this injector and how could it have possibly happened? Is this fixable (sending for cleaning or is it lost)?

I havent flow tested the injectors yet but have moved a good secondary to the primary spot and have 2 greddy 720cc's coming before the weekend to put in the secondaries. In the FSM there were pictures of mixing plates. When I pulled the injectors I did not find them. I looked into where the injectors mount on the intermediate housing and did not find the notches I was looking for. Will this be a problem?

Thanks again.

 

Sorry to interrupt, but my 89TII also has red injectors(if that helps)

 

"Mixing plates" ??? You mean air bleeds? Or is this yet something else on a turbo car I don't have have on my (reliable) n/a?

Stan, if it's not clicking, either the coil is burnt out, or it's so gunked up that the poppet can't even move when the solenoid energizes. You can read the coil for resistance to verify one or the other, but by the time they get this bad, they're hard as hell to clean to the point they work as new again (been there). Just use a secondary in there for now, after checking it carefully (if you haven't already)

 

Wayne- There are airbleeds and also mixing plates. I could find neither unless they are implanted inside the intermediate housing and look like a part of those holes. here is a picture from page 51 of the S5 TII FSM



Yea I figured it was kind of a lost cause to save that injector. I have already replaced it with one from the secondary rail and should be getting my 720s tomorrow or Friday.

 

ON some models air bleeds and mixing plates are one part, on some they are seperate. Nobody thinks much of them...you can run without them with very little issues, if for instance they get broken. You do need the base for support of the injector, though.

Yes, they are inside the LIM and INT housing, and look like theyre part of those. They do NOT come out easily...you WILL break them trying to get them out. Leave them alone and you wont have any problems.

As for your injector, just replace it and go on.

 

Stan- like Kevin said, if they weren't in there, the injectors wouldn't have anything to seat on, so they gotta be in there (at least the top part)...

Yeh, I know what it is now, just never heard them called "mixing plates" before, just "air bleeds"...

 

So they are in there are I shouldnt touch them. Exactly what I wanted to hear. Thanks guys.

 

IF they were not in there, your car would not have run. Your injectors would have nothing to sit on, and fuel pressure would have pushed them out of the rails downward. Unless you removed them, I can assure you they're there. Use a flashlight...you'll then be able to distinguish between the brown plastic air bleeds and the metal around.

 

UPDATE:

Got my car back together. Installed new 720cc injectors and changed some fuel lines while I was down there. Jumpered the fuel pump plug to check for fuel leaks and there were none. Idles pretty good but I am having a problem with my secondaries. Not sure exactly what the problem is but I think it is related to what I had to do to get the greddy 720s in. I basically had to shave off some of the sides where the plug goes onto the injector. I suppose the connection is somewhat loose. I got them to fit as tightly as I could and checked voltage and it was fine.

The car bogs like crazy when I put too much throttle. It just stutters and the rpms dont go up very quickly at all. Backfired very loudly several times as well. I wired in the resistors so I dont think that is the problem.

Could the issue be somewhere else?

 

The problem is TOO MUCH FUEL. Think about it...you said it yourself, that if you apply too much throttle, it sputters and barely revs out. It is flooding itself to death on top end. You need to apply about -30% correction above 4000rpm to try and compensate until you can get tuned. (550cc stockers = 100%, 720cc = 130%)

 

I could have sworn people had 720cc secondaries with similar mods to mine and not having any issues like that.

Would too much fuel also cause me to not be able to boost very much? Or is that just a byproduct of the bogging.

 

I've run 680's on an s4 stock ecu before, with a bit of a bog at 4000, but no real issues in driveability other than some top end power loss. I tried to run 720's on my s5 at once, and it would have none of it...would not even rev over 6krpm. I attributed most of that to my knightsport chip, supposedly richening up the top end, but perhaps it is just an s5 issue. Yes, as engine efficiency decreases, so does turbo efficiency...so if the engine isn't making full power, the turbo won't work as well. I'd say it's all related.