I understand what you are saying. I am however running the same wiring harness. Its a prebuilt Plug and Play harness. I did check the pinouts on the ecm and did a continuity test.

I printed the 200+ page MS3 extra megamanual, and calibrated every sensor. Checked and rechecked that I had the wideband setup correctly, and tried running it with and without wideband correction. I did not just plug the harness in, open the tune and expect it to run.

I agree the tune is probably way off, but it should be hitting on that cylinder if it is close enough to be firing the other cylinders unless there is some sort of issue with the engine.

I guess I am trying to get the thing to hit on all cylinders before I get to focused on the tune, as the misfire isn't doing me any favors for correcting the tune properly.

 

So I'll repeat again.

Are you getting a signal to the injector on cyl6 ? You seem to say yes ?

You also say you've verified 100% visually that fuel is being injected from that injector whilst the engine is turning ?

Same as all other injectors ?

Are you getting a spark at that cylinder ? Is the coil charging correctly ? which in itself is an indication of whether it can also fire correctly.

If you have done these tests properly, then you can rule out the install as far as ecu/wiring/injectors/ignition goes. And yes some of these tests will require a proper multimeter or oscilloscope.

So the problem is with the engine

The fact you claim you have only 10 mins runtime and the inlet port is clean, just shouts there has been a problem with that engine for a very long time.

And again, a single cylinder not firing on a V8 will really have minimal effect on the engine running. If the engine is running badly with a dead cylinder, there are other major problems that need addressed too.


Again, you need a wideband for both banks, it will massively help any diagnosis. Upload a datalog of the engine running, again there should be lots of valuable info in there....again assuming the ecu is setup correctly for any information to make sense to the log viewer.

And I would never suggest to anyone to try and use closed loop on a new install straight off, unless they were 100% sure all elements relating to that closed loop control were spot on.

Blindly hoping and relying on closed loop control can often cause more problems than it helps, especially for an inexperienced person and especially if the engine has running issues. Wideband info is only valid for such tuning if the engine is actually running correctly, otherwise readings can be meaningless for that purpose.

Is the misfire there all the time ? Right from cold, every time, it never fires on that cylinder ?

 

I am getting a signal to all injectors. I did not have the proper tools to verify, so I put a light in the harness and watched the pulses. I then decided that was not accurate enough and sent the ecu back to where I purchased it and they verified all circuits were operating correctly.

The plug is wet everytime I pull it, so there is fuel there. I verified the coil was working, and even swapped it with a known good coil from a running engine.

At this point, I could have had the motor pulled, tore down and reassembled by now but i wanted to make sure I wasn't chasing a phantom in the ECM/wiring/tuning. I think the motor has had an Issue for quite some time before I purchased it. Maybe the cam I bought wasn't ground properly. I have decided to pull the motor tonight and tear it down. I will let you know what I find.

 

Check compression with engine running. Compare bad with good cylinder. Notice if pressure builds or holds the same. Use pressure release to test multiple times while running.

Using an oscilloscope or meter with frequency (AC voltage may give you some insight if only option available) compare bad with good injector pulse.

 

Guys I don't wanna highjack this thread but I'm in deer need of help!!! This is my setup and what I have done to it
243 heads with ls6 springs and rockers
Ls6 cam intake and fuel rails
I am new at this I am mechanically inclined but this is my first attempt at rebuilding an engine I made sure valves where torqued to specs according to the manual and make sure my head bolts torqued to specs as well, timing chain was put back perfectly, I finally got to putting the car together I find it the first time and next thing you know fire coming out of my exhaust manifold side (exhaust manifold is installed all the way to the muffler)
Liquid gas leaking out through the exhaust and catching fire near spark plug ( I'm guessing spark from it causing it to combust)
Keep in mind this car has not been tuned yet it and no o2 sensors in it yet.
But still too much fuel coming out from what I see it's coming from the exhaust manifold and possibly dripping out near the header muffler joint (it is running a little rich too) ugh idk what to do ����

 

You've either some fucked injectors, fucked wiring, fucked ecu, or something else fucked.

No way ever should you have raw fuel running out of the engine.

Have someone competent look at it before you cost yourself a fortune and no not start/run the engine until the problem is resolved, all fuel removed from the engine, the oil/filters drained and replaced etc etc.

 

Just thought I would update this with my findings.

I ended up sending my Gold Box to efi source for a second time. Everything still checked out fine, but I had them replace the injector driver anyway. Finally, I was able to start/idle the motor and make changes to the VE table and see the correlating reaction on the wideband, but it would take extreme changes in ve to make a small AFR difference.

After building a second project powered by a micro-squirt and having very good luck with getting it to run correctly and respond to changes like i though it should, I decided to bite the bullet and order a second, brand new MS3 gold box. I ripped the old one out and put the new one in its place. Same tune, same engine, same everything and my problems have resolved.

 

Thanks for the update, I am having nearly the exact same problem.

 

I was leaning toward something commanding that injector to allow to much fuel, since you pretty much covered everything else. Strange they couldn't test the box and pick up on it, unless somehow you were picking up interference and installing the new box the wiring moved, not likely though.
Hopefully they take the other box back.

 

"Guys I don't wanna highjack this thread but".. You did it, anyway.