please help me!!! dead cylinder.

[eli96talon]

Today I went outside to turn my car on so it would worm up before I went to work.I turn it on find a good radio stattion and my car was idling fine so i go inside to get my stuff before I leave and since my car is load I can here it from inside.all of the sudden I here the car turn off.I was like ugh the dsm gods are in a bad mood today.I go outside and I turn my car on and its misfiring BAD.I open the hood and I check cylinder 3 since I had been having issues with a misfire on that cylinder but only when in boost.I unplug the injector and it has no affect on the misfire.I pull the spark plug wire and its sparking.look at the plug its fine.can someone help me,I know something drastic had to have happend cause it was idling perfrect then died in 1 second.I turn it on and has a huge misfire.could it be a bad ecu? I also tried another coil pack I had there and no luck.please help

 

[Sebba]

Compression test cyl 3.

 

[eli96talon]

I did it has 165...also its hard to believe that in. Min the cylinder lost all compression

 

[GRAVEDIGGER]

What kind of plugs are you running and what is the gap? You need to be using NGK BPR6ES plugs gapped to .028" if you're not already.

 

[96 420a-t]

Swap your number two and number three injectors. See if the problem follows.

 

[eli96talon]

I did what both are suggesting.my gap is. 28 on bpr7es and I don't think that's the issue.like I said the car was idling fine then 1 min. Later it turned off.I turn it back on and it has a bad miss. I also swaped injectors and that did not do the issue.how would a bad ecu act? I've had this issue for a while but only in high boost.I drove 6 hours in my car 2 days ago and didn't misfire unless I went into boost.now today it finally does it at idle,boost and cruising

 

[GRAVEDIGGER]

.I unplug the injector and it has no affect on the misfire.

I just noticed this in your first post. Unplugging the injector should have an effect on the misfire, unless it is your problem. Might look at swapping injectors like 96 420a-t says.

 

[eli96talon]

I swaped injectors,coil pack,ignitor and plug its still on cylinder 3 only.the only thing I haven't done is put my noid light on the injector clip to see if it is get a signal.put when I unpluged cylinder 3 it had no affect on the misfire.also my code reader gave me a code for misfire on cylinder 3.

 

[GRAVEDIGGER]

.my gap is. 28 on bpr7es I also swaped injectors and that did not do the issue

Well then... It could be ecu related. Maybe someone else can chime in with some helpful input. I'm still a bit foggy from last night.

 

[eli96talon]

Yea that's y I ask what are some sighn to look for on a bad ecu

 

[GRAVEDIGGER]

.the only thing I haven't done is put my noid light on the injector clip to see if it is get a signal.put when I unpluged cylinder 3 it had no affect on the misfire.also my code reader gave me a code for misfire on cylinder 3.

Yeah, check that connector for sure. Good luck!

 

[DSMnoobsause]

Check to see if you are getting a signal to cyl 3 injector then work your way back. If you do not see any obvious defects/corrosion. I would use a DVOM "digital volt ohm meter" and test from ecu side of the wiring harness to the injector connector and see if you have high resistance in line or a break in the line. If you to find resistance or a break. Then you will need to trace the harness all the way back to the ECU and find the break.

 

[eli96talon]

That's what I plan to do today...I work on cars alot and know the routine for checking a misfire and this one has me stressed.what is the omhs it should be reading on each injector clip

Just to help clarify this is what I have done to help figure out what the issue is. I checked compression its good.I swaped injectors around and the issue is still on cylinder 3.I swap spark plugs that didn't help.I swaped spark plug wires no help.swaped coil packs (nothing).swaped ignitors(nothing)I even pulled the head off to see if bent valves or something weird was going on.its all good.checked timing its good.boost leak test(nothing)the only last thing is the ecu but idk how to check it.there are no turbo eclipses in any junk yard around here and all my buddies have 97 and up eclipses so ican swap ecu with them

 

[DSMnoobsause]

Sry I should have said if you have any resistance you would need to inspect the wiring harness

 

[bryanwheat]

One side of the injector plug will have constant power and the other goes to the ecu. I would do a continuity to test from the injector plug to the ecu connector. Also check for power at the injector plug. What color is the plug in the cylinder when you pull it out?

 

[eli96talon]

Well at first it looked like a normal plug..after some time it started to turn black.I use the noid lights I have to check for power on the plug....

 

[bryanwheat]

IF it's turning black than i would suspect weak spark or that the injector is hung open.

 

[miguelmcv]

Take the injector off, Buy leave it connected and try to turn the car ON, you will see the injector spraying fuel (if it is Good), If it doesn't, then check your lines.

 

[eli96talon]

I thought it had weak spark so I put new plugs,wires,coil pack,and ignitor.I also put diffrent injectors on it non of that did anything at all.one thing I did notice is that when I had my stock intercooler on there it didn't misfire.then after I put my fmic on there and drove it it was misfiring. Im running 10lbs of boost on a 16g with stock fuel system.

 

[bryanwheat]

Take the injector off, Buy leave it connected and try to turn the car ON, you will see the injector spraying fuel (if it is Good), If it doesn't, then check your lines.

This works good and all until you have an injector shoot out of the rail because of the pressure.

 

[miguelmcv]

This works good and all until you have an injector shoot out of the rail because of the pressure.

Just push them against the valve cover, only to hold the pressure for a sec, which that's all what it will take to know if the injector is Good.

 

[eli96talon]

Well im sure the injectors are spraying cause when it misfires and I pull the plug out I can see all the fuel inside the cylinder

Ok well I just got back from work and came to turn the car on to start doing some diagnosing on it.its idling fine like nothing ever happend,no misfires no nothing!wtf? I know the problem isn't fixed,any ideas

Ok so I did two things diffrent..I took off my boost controller,and on my o2 sensor harness there was a white wire completely striped and there was another totally bare wire touching it.So I fixed that and now it only misfires on cylinder 3 when I go 100% wot. If I stay at 75% at 9lbs it wont misfire.so it got better but still not fixed all the way.