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Steve last won the day on December 27 2018

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  1. Now there`s a difference! I find myself checking in on this post several times a week to see what it all ends up with. So i for one appreciate your updates So your cams are now locked in a fixed position all the time if i get you right?
  2. Great to see you back at it bud. Im sure you know, and its im pretty certain its in the camspecs, but its common for a cam to be spec`d at 0.050" valve lift IIRC (its been a while). Just putting it out there just in case...
  3. A conventional tester would have said everything is just dandy as it only shows the maximum pressure. The car ran on 3 when i got it in (still does as im afraid this car has now done its work). This car was somewhat obvious as it had a kind of a puffing noise. Like you could hear the compression escape somewhere. What i did first was to disconnect the PCV tube between the intake and the valvecover and held a piece of paper in front of the intake port. That made it obvious that there was compression escaping into the intake. So yes a sensor in the intake would tell you there was pulses that wasnt supposed to be there. But was it because of a leaking intakevalve maybe? Took out the glowplug on nr 1 and tested with the WPS and i could tell what really was happening right away.
  4. Sidenote. Here is a car i had yesterday. Problem is a hydraulic lifter resulting in a short EVO duration. About where my markers are set. Care to guess what a conventional compression tester would have showed
  5. Ah. You can actually get the covers of in the car? I had no idea. Well thats great news. Good luck with it all!
  6. There seems to be different resolution/sample rate between this last cyl 3 idle capture and yesterdays capture? On first look it looks like the intake opens SOONER today than i did yesterday. But they seem to close at about the same time. That must be a capture thing i think... There seems to be less exhaust energy from cylinder 2. It makes less pressure in the exhaust compared to the others. Looking back at page on in this thread i see that cyl 2 and 4 got higher compression than the other bank based on your relative compression test. This last intake snap throttle capture shows that those two (2 and 4) creates more pull on the intake during their intake strokes. Sot that probably agrees to more air drawn in on that bank resulting in better compression. I dont know man. Either your Dual AVCS system (thats what you got, right?) is playing games with you. Or the distance between heads changed and skewed timing. Or you got a cam ground wrongly. Or maybe you got one wrong cam (with different specs). Either way your cam timing seems to be different between banks. As you stated on page 1 already. I think we got evidence enough and its time to pull the engine and get yourself a degree wheel and a dial and start measuring actual numbers i am afraid. Unless its something with your AVCS and you can verify it by disabling it. But they should be zeroed at idle according to google (?) On the bright side those engines are relatively easy to pull at least I think(?) Edit: you put the WPS in ZOOM 3 but not RANGE 3. Am i right? OR valve sealing issues for some reason. If an intake valve is leaking on one cylinder it will leak pressure into the intake when its companion cylinder is on its intake stroke, resulting in a lower intake pull (less vacuum)
  7. Steve

    Fuel pressure

    Look at pressure through the DIFFERENTIAL fuel pressure PID instead. Should stay close to your set fuelpressure at all times. Like 300kps (if thats what you set it to or run)
  8. I think the 4 arrows i attached in this picture points at the same point on each cylinder. From there on up there is something wrong on two of them. Also the distance between those points and the nearest TDC/BDC is different in pairs. Two of them are around 30-35 degrees (the two hashy ones) while the two others are around 20-25 degrees. Again this isnt necessarily 100% accurate but indicates differences I bet all these differences equals pretty different AFR`s between cylinders
  9. Measuring the 3 cylinders there definitely seems to be differences between cylinders when it comes to cam timing. Of course my measurements are approximations but still. Your pressure measurements are flawed for some reason The WPS self calibrates when you turn it on, so the issue is probably in the probecalibration in the software. Do you choose the wps in the probemenu? Do you use the automotive software? The pressure should read around 0 psi (or atmospheric pressure) at that plateau at the exhaust stroke. The shape of that plateau looks normal so i suspect its just the readings that are skewed. Or is the software actually reading 0 when the sensor is measuring atmospheric? The manifold pressure reading... Two cylinders seem to be pulling more vacuum than the others. Also that hash on the top of them... Seem suspect. Try setting up the WPS as a pulse sensor. Range 3 zoom 3 IIRC. That way it indicates when pressure is changing and how fast it is changing) instead of pressure.
  10. Alright. I have no idea what stock thickness is but this might certainly be a factor
  11. Do you have a "known good" that tells you the cams are supposed to line up like that with each other and that part of the crank trigger? Since its not adjustable at all there is a question about what changed compared to stock. So.... Is the block skimmed? Are the heads skimmed? Is the headgasket thickness altered. Stuff like that. Heads that are moved further apart or closer to each other will change cam timing Oh. You are in the K range. What scope do you have again? I usually just bump it up to about 10Ms on my 4425
  12. MAYBE its not perfectly ground(?) Just speculating of course, but if its both cylinders we would have to look at what they have in common. IE cams. You dialed in the cams with a degreewheel or something? Or is it a non adjustable system where you just tighten it down and it should be good? Could be that the lobes are a bit offset from what they should have been. The WPS isnt lying so it has to be something there. The lower compression could be as you say because of later opening. Hard to tell as the cranking waveforms dont have rulers set up. And the running ones suffers a bit from slow sample rate/resolution. Can you bump up the samplerate?. However it is the EXHAUST valves that opens there (EVO). Also a perfectly sealed chamber (there is no such thing but just as an example) should have the same amount of air going up as it is going down. So pressure should stay the same. If that made sense. Probably not other than in my head...
  13. Its normal to see little activity during cranking. Camtiming looks mostly OK to me on the running captures and i think you are spot on that it is teh 1mm lift spec playing with your mind here. Looks like there are some differences between sides though. Like the intake valve closes later. Now your cranking captures... You can see that the little "dip" in the pressure after the powerstroke extends lower into "vacuum" on cylinder 1 commpared to cylinder 2. That indicates that MORE of the air trapped in the cylinder during the intakestroke has leaked out of the cylinder during the compression and powerstroke, leaving a vacuum condition in the void when the piston comes down to the BDC again. This also correlates to the lower compression numbers it reaches in that cylinder. Follow so far? Also it looks like the intake vacuum is less on average in cyl 1 than cyl 2. And there seems to be more turbulence. Now to figure where the compression goes... use your nr 1 coil as a reference and for example stick your WPS in the intake somehow (like brakebooster outlet, or evap or wherever) and see if you can catch anything abnormaly through there. And also at the dipstick tube. and the tailpipe. See what you can see. That way you could see wheter the compression goes through the intakevalves, pistonrings or the exhaustvalves. Hooking it up to the coolant tank can also show you if its a headgasket issue. Compression on my own built motor is quite low compared to OEM motor and specs. Its just how it is. Having them equal is more important than comparing them to stock specs. Thinks like camtiming is one thing that changes it And yeah. Scope seems to be a bit low on resolution/samplerate EDIT: Looking again at the cranking captures and what numbers you actually got there im not sure what they are. What compression numbers are you getting again?? Also reading your first post again i see that it was low comp on that BANK, not just one cylinder. Wonder what a capture on cyl 3 and 4 looks like now... Also. If you havent seen this then watch it. About compression numbers captured with the WPS compared to reguular gauges
  14. Set your PC logging to log EVERYTHING. No overrun FC isnt turning on but with the very few parameters you logged i cant see shit.
  15. Good choice on the WPS. I know it hurts the valet like a mofo (as i got one myself and really want another one in addition), but its THE pressuretransducer to get at this day. You can clearly see valve events and put up rotational rulers to measure at what crank degree they happen. Then you look at the odd man out. IE you compare to the other cylinders. A to tight valve clearence would make the valve open early and close late. There is plenty situations that a conventional compression test or leakdowntest wont show.
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