[Levanime]

so, lets make it clear,

car was running fine,
1) U did vcg job
2) Car started misfiring under load on cylinder 1
3) You have swapped injectors, coils, spark plugs from cylinder 1 to others - did not help
4) You have checked compression and all numbers including cylinder 1 are more/less equal
5) Injectors are coded

is this correct?

[f87king]

correct

[Levanime]

what happens if r in neutral or Parking and just rise RPMs?
does it misfire when rpm is high but engine has no load?

[dcafs]

Just putting another possibility out there......worn cam bearing ledges have been known to create misfires.

[feuer]

Originally Posted by dcafs

Just putting another possibility out there......worn cam bearing ledges have been known to create misfires.

How? Please explain further.

[dcafs]

Originally Posted by feuer

How? Please explain further.

Couldn't tell you.....didn't happen to me.

But I recall one of the tuners, Dzenno from years back kept having misfires and could not trace the source of them until his mechanic tore down the engine and found the cam ledges were worn.

I guess cam timing might have had something to do with it......but I remembered the issue, because he was tearing his hair out trying to find the problem.

It got some attention on here because he turned his misfire detection off at one point believing the misfire was a false code, and was criticized for putting his engine at risk for doing so.

The thread may still be on here?

[feuer]

Originally Posted by dcafs

Couldn't tell you.....didn't happen to me.

But I recall one of the tuners, Dzenno from years back kept having misfires and could not trace the source of them until his mechanic tore down the engine and found the cam ledges were worn.

I guess cam timing might have had something to do with it......but I remembered the issue, because he was tearing his hair out trying to find the problem.

It got some attention on here because he turned his misfire detection off at one point believing the misfire was a false code, and was criticized for putting his engine at risk for doing so.

The thread may still be on here?

Purely coincidental if you ask me. Cam ladges will throw Vanos and timing fault codes. Definitely not misfire on single cylinder only like discussed on this thread.

[f87king]

New HPFP same bs. Maybe cracked the valve cover while installing or the mosfets even tho I have MSD81...

[f87king]

Bump someone help

[Levanime]

I fix many DMEs,
never had case or heard that MSD81 mosfets failed.

cracked cover? for sure.

as long as problem started after vcg job reason is related to it.

[f87king]

Originally Posted by Levanime

I fix many DMEs,
never had case or heard that MSD81 mosfets failed.

cracked cover? for sure.

as long as problem started after vcg job reason is related to it.

exactly. theres oil pooling up near cylinder 5. just don't see why thats not the one misfiring. the cover is definitely hairline cracked near 3rd ignition ground I'm thinking of jbwelding or a local guy has one for sale

[Levanime]

no wonders then

keep us posted

[f87king]

Originally Posted by Levanime

no wonders then

keep us posted

thanks bro will do getting new turbos/single kit within the next few weeks as long as I get this fixed

[Jklad]

Great example of why you should just replace the whole valve cover rather than just replacing the gasket. It's the same amount of work( or less) and costs only a couple hundred more in parts for Fresh, clean shit, as long as your careful not to crack it during install. Do it once, do it right.

[f87king]

New valve cover and gasket today and a walnut blast same thing. This is crazy I looked inside of spark plug wells and 1 looked dry and 2-6 looked black weird

[RSL]

Originally Posted by e92335xi

B4 changing tune coils plugs gasket I had a no misfire car and great logs to show for it. Now my rail pressure is low

2 pages of stuff you've changed, I didn't see it mentioned that you reverted to the previous tune/stock bin to see if it stops, unless I missed it.

Where are logs?

[f87king]

Originally Posted by RSL

2 pages of stuff you've changed, I didn't see it mentioned that you reverted to the previous tune/stock bin to see if it stops, unless I missed it.

Where are logs?

http://datazap.me/u/tomhondros/misfire-log-2-2-0

http://datazap.me/u/tomhondros/misfi...-20&mark=34-48

tuner mentioned o2s just now

[RSL]

Originally Posted by e92335xi

http://datazap.me/u/tomhondros/misfire-log-2-2-0

http://datazap.me/u/tomhondros/misfi...-20&mark=34-48

tuner mentioned o2s just now

Yeah, bank 1 is just getting doused with fuel. Misfire is either fuel fouling or just keeping the plug so cold it doesn't reach self-cleaning temp. -34% trims on bank 1, still hits 10:1 AFR and that's when HPFP drops. It's hitting cat protection, but doesn't look like dropping into open loop. You may very likely just have a tune issue. Flash back to the original bin or last known "clean" tune and test. If it's resolved, issue is solely in the tune. Stop throwing money and parts at it until you've confirmed it's an actual parts problem.

[f87king]

Originally Posted by RSL

Yeah, bank 1 is just getting doused with fuel. Misfire is either fuel fouling or just keeping the plug so cold it doesn't reach self-cleaning temp. -34% trims on bank 1, still hits 10:1 AFR and that's when HPFP drops. It's hitting cat protection, but doesn't look like dropping into open loop. You may very likely just have a tune issue. Flash back to the original bin or last known "clean" tune and test. If it's resolved, issue is solely in the tune. Stop throwing money and parts at it until you've confirmed it's an actual parts problem.

I've changed tunes but I will flash a MHD OTS tune tomorrow and see.

[RSL]

If it does it on the OTS map too, you've at least narrowed it down. Those logs were on a E60 map, so guessing they're commanding a huge HPFP/scalars and if you were short on E85 or the E85 content wasn't as advertised, that would do it.

If you are running a tank of E85 right now, be careful with the current blend amount in there and which OTS map you dump back in, it might go just as bad in the other direction (lean) on a pump map. You may need to add pump gas to bring the blend down or just fill with straight 93 and test a pump gas OTS map.

[f87king]

Originally Posted by RSL

If it does it on the OTS map too, you've at least narrowed it down. Those logs were on a E60 map, so guessing they're commanding a huge HPFP/scalars and if you were short on E85 or the E85 content wasn't as advertised, that would do it.

If you are running a tank of E85 right now, be careful with the current blend amount in there and which OTS map you dump back in, it might go just as bad in the other direction (lean) on a pump map. You may need to add pump gas to bring the blend down or just fill with straight 93 and test a pump gas OTS map.

Did the 93 MHD map eased into throttle for a full pull so you can check whats up

[RSL]

Originally Posted by e92335xi

Did the 93 MHD map eased into throttle for a full pull so you can check whats up

You've definitely got issues, but that E60 map really makes a mess, stay off it until you get things sorted. I expected the OTS map to behave better with less demand from the fuel system, and it does to some extent, but the flat AFR, no boost and still falling HPFP on it are perplexing. On the 93 map, AFRs would seem to indicate it's in open loop (stoich throughout), but it's trimming, which would make me think that it's not open loop and O2s are working fine. Why it's targeting little/no boost and flat AFR is the question...maybe it is in a limp mode.

If it were me, I'd go all the way back to square one. Do a full/long write back to the OEM bin with absolutely no flash-time options (unless 3.5 bar if you have one installed) and use INPA to reset all AFR/injector/fuel pump adaptations, run 93 only and try again to take anything tune-related completely off the table.

You have not had any other codes besides the cyl 1 misfire? Were they cleared and car restarted prior to the 93 OTS pull? Did you do a leak down test or just a compression test?

I'll keep thinking on this, but moved in a whole other direction than I was expecting at this point...