Im pretty sure its either electrical or gas, goodluck.

 

Drove it around a bit today for the first time.. below 3500 rpms there is NO power but as soon as i hit above like 3500 3600 it snaps back on like nothin ever happened... primary injectors?

 

Did you try snapping the injectors with voltage?

 

After driving it around, does the problem still exist? Is it back to normal?

 

all the injectors were tested individually and we heard snapping sounds so we know they are opening and shutting.. can one open and still be clogged? and my tech who is looking over it now says he thinks im not getting consistant or enough spark on the front rotor.. thats the one running extra rich.. he is saying he thinks my leading coil is going bad i dont wana replace it and it not fix the problem that would suck It just sounds really muffled on the bottom end i geuss maybe its because the fuel on the rotor is extinguishing the spark.. i hate playing guessing games..

 

UPDATE
So we know for sure now that its the rear rotor thats running. We pulled the brand new leadings today and the front one is burn looking only around the middle like its sparking but the rest of the plug is clean.. the rear one looks dirty all around like combustion is happening. We plugged the wire from the other primary into the primary of the rotor that isnt running and it wouldnt run at all.. so that must mean its a problem with that injector right? well it clicks when you test it so i wonder whats going on...

 

Testing the coil should be fairly easy... The FSM outlines the ohm specs. Also test the coil harness for continuity. Ensure there is continuity.

Use a stethascope and put it on the front rotor injector while you crank the engine. You should be able to hear it snapping open and shut. If it istn't, then the signal isn't getting from the ECU.

 

we thought about that he said he has had failed fuel injector drivers on a PFC before thats why we tryed plugging it in with the injector plug we knew was sending signal.. he is waiting for the snap on guy to bring his steth back

 

i cant stop thinking about the fact that at like 3500 or 3600 its like that other rotor fires on and kicks in you can feel it VERY noticable.. i figured maybe that would help me narrow it down but nobody seems to know.. WHERE ARE THE ROTOR GODS?

 

You can buy them at Advance Auto for under $20....

God helps thos who help themselves. You are in the drivers seat bro. Think of this as good experience.

Could very well be a primary injector not firing. After 3600 does it run "smooth & perfect" as it should? Or does it just run better, but still not right? I would do this.....

1. FUEL - Test primary injectors with a stethascope on startup. Test continuity from each injector plug, back to the ECU for negative wire on ALL injectors. Ensure each injector is getting power from positive wire. Swap injectors. Swap ECU.

2. SPARK - I would start by testing the coils, iginition harness, and plug wires. At idle, test each wire with a timing light to ensure a steady spark. Then, attach the timing light to each wire, secure the light leads to power, tape the trigger down, and tape it to my windshield with the light facing me. Then drive it and watch for a change in the spark. I would do this to both leading and trailing. You are looking for a visual abnormal change. If you can see it as the car runs differnetly, there is a spark problem. Testing the plugs themselves was a good idea. I have seen 2 new plugs from a pack of 4 not fire. Dead from the box.

This isn't rocket science, its just a well hidden problem. You have to test each system and component thoroughly. Eliminate every possible scenario to the point where you know it isn't the problem, then move on. If you only look at certain angles, you could miss the issue completely.

 

ok.. never heard of using a timing light in that fashion.. so you want me to stare at a strobe light in my window while im driving? sounds good. maybe i am misunderstanding you.

 

ok the leading plug on the front rotor is burnt out no black stuff just burnt up from the spark.. but the trailing plug for that same rotor has the black buildup all around it like its hitting the fuel and combustion is happening.. strange.. is it possible the timing could have jumped off some how? i think one of my pullys is loose i can hear it squeeking. and another interesting thing to note is adjusting the idle with the power fc doesnt affect idle at all.. but everything else seems to work.. still running on one rotor until boost builds and secondaries kick in i wish i knew what was wrong its driving me nuts.

 

XLR8 just gave you the play by play on how to diagnose. Now's your turn to step up to the plate and be a hero. Or take it to somebody who will.

Internetz said what needs to be done but internetz has no arms to fix it for you.

 

Hey bud i got no problem doing things myself but when i showed my tech this post about driving down the road watching a timing light in your window he suggested that i not take that advice so i was making sure.. no need to be so smug about ****.

 

My FD single turbo did something similar last week and I havent touched it yet. But I assume its my injector. It sounds like its a full bridgeport at idle but if i give ~10% throttle the bitch lurches forward no problem, give it more throttle and it dies.

I plan to disconnect the primary injector housing tomorrow and test the spray patterns. Ill keep you posted.

And yrs ago I took my first Fd to Rotorsports when I was stationed up there and have NEVER had better service from anyone since. If I wasnt in FL I would still be going there.

 

yeah it does sound like a full bridge but im pretty sure thats just the rear rotor firing... i swear when you get above 3500 rpms you can feel that other rotor kicking in i wonder if it has something to o with ignition changing, or the secondary injectors opening, or maybe just something to do with the boost making it work i dunno but im going to try driving it with a timing light im running out of things to test... its just so strange that it happened while sitting for like 4 hours. or maybe it was electrical and whatever it is that failed woundnt show symptoms until restart.. keep me posted on what you find.

 

BTW like i said before after the problem happened i put brand new leading and trailing plugs.. if i remember correctly all of them has black residue EXCEPT for the front leading which just had burn marks in the center but the rest of the surface of the plug looks shiney and new.. hmmm

 

Sorry man, got as far testing spark and one of my leading coils is 1/3 the power as the other, so until I get a replacement she'll sit.

My plugs were identical, so i don't think it was an injector.

There was some sludge in my plug wire, which may be causing me problems...

 

Bryan sent me two primary injectors (850cc i believe) when they get here ill swap em in and cross my fingers.. if not i really dont know what else to do except replace all my coils and my ignitor and then replace the power fc.. i feel like ive checked everything else..

 

What color are they?

 

havent got them yet

 

If I remember correctly stock 550cc primaries are purple and the secondary 850ccs are red.

 

i dont have a stock fuel system.. my power fc is programmed for 860cc primaries.

 

Im just making sure you get the right ones. I run stock 850s as primaries as well...

 

One thing ive found while searching these forums is when somebodys problem is fixed half of them never come back and report what the problem was.. come on people contribute to your community..

THE PROBLEM WAS SOLVED.

What was it? A fueling issue.. the primary fuel rail is aftermarket.. when my tech first installed everything i remember he had a problem with the oring sealing and fuel was spraying out one of them so we gotta use these fat orings and they have to be seated in there just right and its hard to tell once they are in if you sealed them perfect or if its a little off.. well what happened is when bryan (or one of his techs) put them back on after the build he didnt know about that little prob and without realizing it one of the primary orings was crushed in there sideways and the problem just got worse over a week or two of driving.. it was literally blocking fuel flow from one of my primaries. So he countersynced the holes and a little modification and she runs beautifully.. the tune is a little off but i expected that being as that it was tuned with the problem at its early stage.

Thnx for all the help guys!